From f75f1d632139a6c415c298af69b16b159541c72f Mon Sep 17 00:00:00 2001
From: jpawlowski <jpawlowski@users.noreply.github.com>
Date: Mon, 7 Nov 2016 06:19:04 +0000
Subject: [PATCH] Unit.pm: first part to integration dimensions

git-svn-id: https://svn.fhem.de/fhem/trunk@12517 2b470e98-0d58-463d-a4d8-8e2adae1ed80
---
 fhem/FHEM/Unit.pm | 3076 ++++++++++++++++++++++++++-------------------
 1 file changed, 1782 insertions(+), 1294 deletions(-)

diff --git a/fhem/FHEM/Unit.pm b/fhem/FHEM/Unit.pm
index fbe619f3b..d109a29ba 100644
--- a/fhem/FHEM/Unit.pm
+++ b/fhem/FHEM/Unit.pm
@@ -37,11 +37,13 @@ sub ReadingsUnit($$@) {
         $ud = Unit::GetDetailsFromReadingname( $n, $lang );
     }
 
-    return $ud->{"unit"} if ( !$format && defined( $ud->{"unit"} ) );
-    return $ud->{"unit_long"}
-      if ( $format && $format eq "1" && defined( $ud->{"unit_long"} ) );
-    return $ud->{"unit_abbr"}
-      if ( $format && $format eq "2" && defined( $ud->{"unit_abbr"} ) );
+    return $ud->{unit_symbol}
+      if ( !$format && defined( $ud->{unit_symbol} ) );
+    return $ud->{unit} if ( !$format && defined( $ud->{unit} ) );
+    return $ud->{unit_long}
+      if ( $format && $format eq "1" && defined( $ud->{unit_long} ) );
+    return $ud->{unit_abbr}
+      if ( $format && $format eq "2" && defined( $ud->{unit_abbr} ) );
     return $default;
 }
 
@@ -420,1560 +422,2018 @@ sub CommandDeleteunit($$$) {
 
 package Unit;
 
-my %unit_types = (
-    0  => "mathematics",
-    1  => "temperature",
-    2  => "pressure",
-    3  => "currency",
-    4  => "length",
-    5  => "time",
-    6  => "speed",
-    7  => "weight",
-    8  => "solar",
-    9  => "volume",
-    10 => "energy",
+my %autoscale = (
+    '0'     => { format => '%i',   scale => 1000, },
+    '0.001' => { format => '%i',   scale => 1000, },
+    '0.1'   => { format => '%.1f', scale => 1, },
+    '10'    => { format => '%i',   scale => 1, },
+    '1.0e3' => { format => '%.1f', scale => 0.001, },
+    '2.0e3' => { format => '%i',   scale => 0.001, },
+    '1.0e6' => { format => '%.1f', scale => 0.001, },
+    '2.0e6' => { format => '%i',   scale => 0.001, },
 );
 
-my %unitsDB = (
-
-    #TODO really translate all languages
-
-    # math
-    "deg" => {
-        "unit_type" => 0,
-        "unit"      => "°",
-        "unit_long" => {
-            "de" => "Grad",
-            "en" => "degree",
-            "fr" => "degree",
-            "nl" => "degree",
-            "pl" => "degree",
+my %scales_m = (
+    '1.0e-12' => {
+        'scale'      => 'p',
+        'scale_long' => {
+            de => 'Piko',
+            en => 'pico',
+            fr => 'pico',
+            nl => 'pico',
+            pl => 'pico',
         },
     },
 
-    "pct" => {
-        "unit_type" => 0,
-        "unit"      => "%",
-        "unit_long" => {
-            "de" => "Prozent",
-            "en" => "percent",
-            "fr" => "percent",
-            "nl" => "percent",
-            "pl" => "percent",
+    '1.0e-9' => {
+        'scale'      => 'n',
+        'scale_long' => {
+            de => 'Nano',
+            en => 'nano',
+            fr => 'nano',
+            nl => 'nano',
+            pl => 'nano',
+        },
+    },
+
+    '1.0e-6' => {
+        'scale'      => 'μ',
+        'scale_long' => {
+            de => 'Mikro',
+            en => 'micro',
+            fr => 'micro',
+            nl => 'micro',
+            pl => 'micro',
+        },
+    },
+
+    '1.0e-3' => {
+        'scale'      => 'm',
+        'scale_long' => {
+            de => 'Milli',
+            en => 'mili',
+            fr => 'mili',
+            nl => 'mili',
+            pl => 'mili',
+        },
+    },
+
+    '1.0e-2' => {
+        'scale'      => 'c',
+        'scale_long' => {
+            de => 'Zenti',
+            en => 'centi',
+            fr => 'centi',
+            nl => 'centi',
+            pl => 'centi',
+        },
+    },
+
+    '1.0e-1' => {
+        'scale'      => 'd',
+        'scale_long' => {
+            de => 'Dezi',
+            en => 'deci',
+            fr => 'deci',
+            nl => 'deci',
+            pl => 'deci',
+        },
+    },
+
+    '1.0e0' => {
+        'scale'      => '',
+        'scale_long' => '',
+    },
+
+    '1.0e1' => {
+        'scale'      => 'da',
+        'scale_long' => {
+            de => 'Deka',
+            en => 'deca',
+            fr => 'deca',
+            nl => 'deca',
+            pl => 'deca',
+        },
+    },
+
+    '1.0e2' => {
+        'scale'      => 'h',
+        'scale_long' => {
+            de => 'Hekto',
+            en => 'hecto',
+            fr => 'hecto',
+            nl => 'hecto',
+            pl => 'hecto',
+        },
+    },
+
+    '1.0e3' => {
+        'scale'      => 'k',
+        'scale_long' => {
+            de => 'Kilo',
+            en => 'kilo',
+            fr => 'kilo',
+            nl => 'kilo',
+            pl => 'kilo',
+        },
+    },
+
+    '1.0e6' => {
+        'scale'      => 'M',
+        'scale_long' => {
+            de => 'Mega',
+            en => 'mega',
+            fr => 'mega',
+            nl => 'mega',
+            pl => 'mega',
+        },
+    },
+);
+
+my %scales_sq = (
+    'scale'      => '2',
+    'scale_long' => {
+        de => 'Quadrat',
+        en => 'square',
+        fr => 'square',
+        nl => 'square',
+        pl => 'square',
+    },
+);
+
+my %scales_cu = (
+    'scale'      => '3',
+    'scale_long' => {
+        de => 'Kubik',
+        en => 'cubic',
+        fr => 'cubic',
+        nl => 'cubic',
+        pl => 'cubic',
+    },
+);
+
+my %unit_base = (
+
+  # based on https://de.wikipedia.org/wiki/Liste_physikalischer_Gr%C3%B6%C3%9Fen
+
+    0 => {
+        dimension      => 'L',
+        formula_symbol => 'l',
+        base_unit      => 'm',
+        base_parameter => {
+            de => 'Länge',
+            en => 'length',
+            fr => 'length',
+            nl => 'length',
+            pl => 'length',
+        },
+    },
+
+    1 => {
+        dimension      => 'M',
+        formula_symbol => 'm',
+        base_unit      => 'kg',
+        base_parameter => {
+            de => 'Masse',
+            en => 'mass',
+            fr => 'mass',
+            nl => 'mass',
+            pl => 'mass',
+        },
+    },
+
+    2 => {
+        dimension      => 'T',
+        formula_symbol => 't',
+        base_unit      => 's',
+        base_parameter => {
+            de => 'Zeit',
+            en => 'time',
+            fr => 'time',
+            nl => 'time',
+            pl => 'time',
+        },
+    },
+
+    3 => {
+        dimension      => 'I',
+        formula_symbol => 'i',
+        base_unit      => 'a',
+        base_parameter => {
+            de => 'elektrische Stromstärke',
+            en => 'electric current',
+            fr => 'electric current',
+            nl => 'electric current',
+            pl => 'electric current',
+        },
+    },
+
+    4 => {
+        dimension      => 'θ',
+        formula_symbol => 'T',
+        base_unit      => 'k',
+        base_parameter => {
+            de => 'absolute Temperatur',
+            en => 'absolute temperature',
+            fr => 'absolute temperature',
+            nl => 'absolute temperature',
+            pl => 'absolute temperature',
+        },
+    },
+
+    5 => {
+        dimension      => 'N',
+        formula_symbol => 'n',
+        base_unit      => 'mol',
+        base_parameter => {
+            de => 'Stoffmenge',
+            en => 'amount of substance',
+            fr => 'amount of substance',
+            nl => 'amount of substance',
+            pl => 'amount of substance',
+        },
+    },
+
+    6 => {
+        dimension      => 'J',
+        formula_symbol => 'Iv',
+        base_unit      => 'cd',
+        base_parameter => {
+            de => 'Lichtstärke',
+            en => 'luminous intensity',
+            fr => 'luminous intensity',
+            nl => 'luminous intensity',
+            pl => 'luminous intensity',
+        },
+    },
+
+    7 => {
+        dimension      => 'M L^2 T^−2',
+        formula_symbol => 'E',
+        base_unit      => 'j',
+        base_parameter => {
+            de => 'Energie',
+            en => 'energy',
+            fr => 'energy',
+            nl => 'energy',
+            pl => 'energy',
+        },
+    },
+
+    8 => {
+        dimension      => 'T^−1',
+        formula_symbol => 'f',
+        base_unit      => 'hz',
+        base_parameter => {
+            de => 'Frequenz',
+            en => 'frequency',
+            fr => 'frequency',
+            nl => 'frequency',
+            pl => 'frequency',
+        },
+    },
+
+    9 => {
+        dimension      => 'M L^2 T^−3',
+        formula_symbol => 'P',
+        base_unit      => 'w',
+        base_parameter => {
+            de => 'Leistung',
+            en => 'power',
+            fr => 'power',
+            nl => 'power',
+            pl => 'power',
+        },
+    },
+
+    10 => {
+        dimension      => 'M L^−1 T^−2',
+        formula_symbol => 'p',
+        base_unit      => 'pa',
+        base_parameter => {
+            de => 'Druck',
+            en => 'pressure',
+            fr => 'pressure',
+            nl => 'pressure',
+            pl => 'pressure',
+        },
+    },
+
+    11 => {
+        dimension      => 'M L^−1 T^−2',
+        formula_symbol => 'pabs',
+        base_unit      => 'pabs',
+        base_parameter => {
+            de => 'absoluter Druck',
+            en => 'absolute pressure',
+            fr => 'absolute pressure',
+            nl => 'absolute pressure',
+            pl => 'absolute pressure',
+        },
+    },
+
+    12 => {
+        dimension      => 'M L^−1 T^−2',
+        formula_symbol => 'pamb',
+        base_unit      => 'pamb',
+        base_parameter => {
+            de => 'Luftdruck',
+            en => 'air pressure',
+            fr => 'air pressure',
+            nl => 'air pressure',
+            pl => 'air pressure',
+        },
+    },
+
+    13 => {
+        dimension      => 'M L^2 T^−3 I^−1',
+        formula_symbol => 'U',
+        base_unit      => 'v',
+        base_parameter => {
+            de => 'elektrische Spannung',
+            en => 'electric voltage',
+            fr => 'electric voltage',
+            nl => 'electric voltage',
+            pl => 'electric voltage',
+        },
+    },
+
+    14 => {
+        dimension      => '1',
+        formula_symbol => '',
+        base_unit      => 'rad',
+        base_parameter => {
+            de => 'ebener Winkel',
+            en => 'plane angular',
+            fr => 'plane angular',
+            nl => 'plane angular',
+            pl => 'plane angular',
+        },
+    },
+
+    15 => {
+        dimension      => 'L T^−1',
+        formula_symbol => 'v',
+        base_unit      => 'kmh',
+        base_parameter => {
+            de => 'Geschwindigkeit',
+            en => 'speed',
+            fr => 'speed',
+            nl => 'speed',
+            pl => 'speed',
+        },
+    },
+
+    16 => {
+        dimension      => 'L^−2 J',
+        formula_symbol => 'Ev',
+        base_unit      => 'lx',
+        base_parameter => {
+            de => 'Beleuchtungsstärke',
+            en => 'illumination intensity',
+            fr => 'illumination intensity',
+            nl => 'illumination intensity',
+            pl => 'illumination intensity',
+        },
+    },
+
+    17 => {
+        dimension      => 'J',
+        formula_symbol => 'F',
+        base_unit      => 'lm',
+        base_parameter => {
+            de => 'Lichtstrom',
+            en => 'luminous flux',
+            fr => 'luminous flux',
+            nl => 'luminous flux',
+            pl => 'luminous flux',
+        },
+    },
+
+    18 => {
+        dimension      => 'L^3',
+        formula_symbol => 'V',
+        base_unit      => 'm3',
+        base_parameter => {
+            de => 'Volumen',
+            en => 'volume',
+            fr => 'volume',
+            nl => 'volume',
+            pl => 'volume',
+        },
+    },
+
+    19 => {
+        dimension      => '1',
+        formula_symbol => 'B',
+        base_unit      => 'b',
+        base_parameter => {
+            de => 'Logarithmische Größe',
+            en => 'logarithmic level',
+            fr => 'logarithmic level',
+            nl => 'logarithmic level',
+            pl => 'logarithmic level',
+        },
+    },
+
+    20 => {
+        dimension      => 'I T',
+        formula_symbol => 'C',
+        base_unit      => 'coul',
+        base_parameter => {
+            de => 'elektrische Ladung',
+            en => 'electric charge',
+            fr => 'electric charge',
+            nl => 'electric charge',
+            pl => 'electric charge',
+        },
+    },
+
+    21 => {
+        dimension      => '',
+        formula_symbol => 'F',
+        base_unit      => 'far',
+        base_parameter => {
+            de => 'elektrische Kapazität',
+            en => 'electric capacity',
+            fr => 'electric capacity',
+            nl => 'electric capacity',
+            pl => 'electric capacity',
+        },
+    },
+
+    22 => {
+        dimension      => '',
+        formula_symbol => 'F',
+        base_unit      => 'far',
+        base_parameter => {
+            de => 'elektrische Widerstand',
+            en => 'electric resistance',
+            fr => 'electric resistance',
+            nl => 'electric resistance',
+            pl => 'electric resistance',
+        },
+    },
+);
+
+#TODO really translate all languages
+my %unitsDB = (
+
+    pct => {
+
+        unit_symbol => '%',
+        unit_long   => {
+            de => 'Prozent',
+            en => 'percent',
+            fr => 'percent',
+            nl => 'percent',
+            pl => 'percent',
+        },
+
+        txt_format => '%value% %unit_symbol%',
+    },
+
+    gon => {
+
+        base_ref    => 14,
+        unit_symbol => '°',
+        unit        => 'gon',
+        unit_long   => {
+            de => 'Grad',
+            en => 'gradians',
+            fr => 'gradians',
+            nl => 'gradians',
+            pl => 'gradians',
+        },
+        txt_format => '%value%%unit_symbol%',
+    },
+
+    rad => {
+        base_ref  => 14,
+        unit      => 'rad',
+        unit_long => {
+            de => 'Radiant',
+            en => 'radiant',
+            fr => 'radiant',
+            nl => 'radiant',
+            pl => 'radiant',
         },
     },
 
     # temperature
-    "c" => {
-        "unit_type" => 1,
-        "unit"      => "°C",
-        "unit_long" => {
-            "de" => "Grad Celsius",
-            "en" => "Degree Celsius",
-            "fr" => "Degree Celsius",
-            "nl" => "Degree Celsius",
-            "pl" => "Degree Celsius",
+    c => {
+        base_ref    => 2,
+        unit_symbol => chr(0xC2) . chr(0xB0) . 'C',
+        unit        => 'C',
+        unit_long   => {
+            de => 'Grad Celsius',
+            en => 'Degrees Celsius',
+            fr => 'Degrees Celsius',
+            nl => 'Degrees Celsius',
+            pl => 'Degrees Celsius',
         },
+        txt_format => '%value%%unit_symbol%',
     },
 
-    "f" => {
-        "unit_type" => 1,
-        "unit"      => "°F",
-        "unit_long" => {
-            "de" => "Grad Fahrenheit",
-            "en" => "Degree Fahrenheit",
-            "fr" => "Degree Fahrenheit",
-            "nl" => "Degree Fahrenheit",
-            "pl" => "Degree Fahrenheit",
+    f => {
+        base_ref    => 2,
+        unit_symbol => chr(0xC2) . chr(0xB0) . 'F',
+        unit        => 'F',
+        unit_long   => {
+            de => 'Grad Fahrenheit',
+            en => 'Degree Fahrenheit',
+            fr => 'Degree Fahrenheit',
+            nl => 'Degree Fahrenheit',
+            pl => 'Degree Fahrenheit',
         },
+        txt_format => '%value% %unit_symbol%',
     },
 
-    "k" => {
-        "unit_type" => 1,
-        "unit"      => "K",
-        "unit_long" => {
-            "de" => "Kelvin",
-            "en" => "Kelvin",
-            "fr" => "Kelvin",
-            "nl" => "Kelvin",
-            "pl" => "Kelvin",
+    k => {
+        base_ref  => 2,
+        unit      => 'K',
+        unit_long => {
+            de => 'Kelvin',
+            en => 'Kelvin',
+            fr => 'Kelvin',
+            nl => 'Kelvin',
+            pl => 'Kelvin',
         },
     },
 
     # pressure
-    "bar" => {
-        "unit_type" => 3,
-        "unit"      => "bar",
-        "unit_long" => {
-            "de" => "Bar",
-            "en" => "Bar",
-            "fr" => "Bar",
-            "nl" => "Bar",
-            "pl" => "Bar",
+    bar => {
+        base_ref     => 10,
+        unit_scale_m => '1.0e0',
+        unit         => 'bar',
+        unit_long    => {
+            de => 'Bar',
+            en => 'Bar',
+            fr => 'Bar',
+            nl => 'Bar',
+            pl => 'Bar',
         },
     },
 
-    "pa" => {
-        "unit_type" => 3,
-        "unit"      => "Pa",
-        "unit_long" => {
-            "de" => "Pascal",
-            "en" => "Pascal",
-            "fr" => "Pascal",
-            "nl" => "Pascal",
-            "pl" => "Pascal",
+    mbar => {
+        unit_ref     => 'bar',
+        unit_scale_m => '1.0e-3',
+    },
+
+    pa => {
+        base_ref     => 10,
+        unit_scale_m => '1.0e0',
+        unit         => 'Pa',
+        unit_long    => {
+            de => 'Pascal',
+            en => 'Pascal',
+            fr => 'Pascal',
+            nl => 'Pascal',
+            pl => 'Pascal',
         },
     },
 
-    "hpa" => {
-        "unit_type" => 3,
-        "unit"      => "hPa",
-        "unit_long" => {
-            "de" => "Hecto Pascal",
-            "en" => "Hecto Pascal",
-            "fr" => "Hecto Pascal",
-            "nl" => "Hecto Pascal",
-            "pl" => "Hecto Pascal",
+    hpa => {
+        unit_ref     => 'pa',
+        unit_scale_m => '1.0e2',
+    },
+
+    pamb => {
+        base_ref     => 12,
+        unit_scale_m => '1.0e0',
+        unit         => 'Pa',
+        unit_long    => {
+            de => 'Pascal',
+            en => 'Pascal',
+            fr => 'Pascal',
+            nl => 'Pascal',
+            pl => 'Pascal',
         },
     },
 
-    "inhg" => {
-        "unit_type" => 3,
-        "unit"      => "inHg",
-        "unit_long" => {
-            "de" => "Zoll Quecksilbersäule",
-            "en" => "Inches of Mercury",
-            "fr" => "Inches of Mercury",
-            "nl" => "Inches of Mercury",
-            "pl" => "Inches of Mercury",
+    hpamb => {
+        unit_ref     => 'pamb',
+        unit_scale_m => '1.0e2',
+    },
+
+    inhg => {
+        base_ref  => 12,
+        unit      => 'inHg',
+        unit_long => {
+            de => 'Zoll Quecksilbersäule',
+            en => 'Inches of Mercury',
+            fr => 'Inches of Mercury',
+            nl => 'Inches of Mercury',
+            pl => 'Inches of Mercury',
         },
     },
 
-    "mmhg" => {
-        "unit_type" => 3,
-        "unit"      => "mmHg",
-        "unit_long" => {
-            "de" => "Millimeter Quecksilbersäule",
-            "en" => "Milimeter of Mercury",
-            "fr" => "Milimeter of Mercury",
-            "nl" => "Milimeter of Mercury",
-            "pl" => "Milimeter of Mercury",
-        },
-    },
-
-    "torr" => {
-        "unit_type" => 3,
-        "unit"      => "Torr",
-    },
-
-    "psi" => {
-        "unit_type" => 3,
-        "unit"      => "psi",
-        "unit_long" => {
-            "de" => "Pfund pro Quadratzoll",
-            "en" => "Pound-force per square inch",
-            "fr" => "Pound-force per square inch",
-            "nl" => "Pound-force per square inch",
-            "pl" => "Pound-force per square inch",
-        },
-    },
-
-    "psia" => {
-        "unit_type" => 3,
-        "unit"      => "psia",
-        "unit_long" => {
-            "de" => "Pfund pro Quadratzoll absolut",
-            "en" => "pound-force per square inch absolute",
-            "fr" => "pound-force per square inch absolute",
-            "nl" => "pound-force per square inch absolute",
-            "pl" => "pound-force per square inch absolute",
-        },
-    },
-
-    "psig" => {
-        "unit_type" => 3,
-        "unit"      => "psig",
-        "unit_long" => {
-            "de" => "Pfund pro Quadratzoll relativ",
-            "en" => "pounds-force per square inch gauge",
-            "fr" => "pounds-force per square inch gauge",
-            "nl" => "pounds-force per square inch gauge",
-            "pl" => "pounds-force per square inch gauge",
+    mmhg => {
+        base_ref  => 12,
+        unit      => 'mmHg',
+        unit_long => {
+            de => 'Millimeter Quecksilbersäule',
+            en => 'Milimeter of Mercury',
+            fr => 'Milimeter of Mercury',
+            nl => 'Milimeter of Mercury',
+            pl => 'Milimeter of Mercury',
         },
     },
 
     # length
-    "km" => {
-        "unit_type" => 4,
-        "unit"      => "km",
-        "unit_long" => {
-            "de" => "Kilometer",
-            "en" => "kilometer",
-            "fr" => "kilometer",
-            "nl" => "kilometer",
-            "pl" => "kilometer",
+    km => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e3',
+    },
+
+    hm => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e2',
+    },
+
+    dam => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e1',
+    },
+
+    m => {
+        base_ref     => 0,
+        unit_scale_m => '1.0e0',
+        unit         => 'm',
+        unit_long    => {
+            de => 'Meter',
+            en => 'meter',
+            fr => 'meter',
+            nl => 'meter',
+            pl => 'meter',
         },
     },
 
-    "m" => {
-        "unit_type" => 4,
-        "unit"      => "m",
-        "unit_long" => {
-            "de" => "Meter",
-            "en" => "meter",
-            "fr" => "meter",
-            "nl" => "meter",
-            "pl" => "meter",
+    dm => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e-1',
+    },
+
+    cm => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e-2',
+    },
+
+    mm => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e-3',
+    },
+
+    um => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e-6',
+    },
+
+    nm => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e-9',
+    },
+
+    pm => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e-12',
+    },
+
+    fm => {
+        unit_ref     => 'm',
+        unit_scale_m => '1.0e-15',
+    },
+
+    in => {
+        base_ref    => 4,
+        unit_symbol => '″',
+        unit        => 'in',
+        unit_long   => {
+            de => 'Zoll',
+            en => 'inch',
+            fr => 'inch',
+            nl => 'inch',
+            pl => 'inch',
+        },
+        unit_long_pl => {
+            de => 'Zoll',
+            en => 'inches',
+            fr => 'inches',
+            nl => 'inches',
+            pl => 'inches',
+        },
+        txt_format         => '%value%%unit_symbol%',
+        txt_format_long    => '%value% %unit_long%',
+        txt_format_long_pl => '%value% %unit_long_pl%',
+    },
+
+    ft => {
+        base_ref    => 0,
+        unit_symbol => '′',
+        unit        => 'ft',
+        unit_long   => {
+            de => 'Fuss',
+            en => 'foot',
+            fr => 'foot',
+            nl => 'foot',
+            pl => 'foot',
+        },
+        unit_long_pl => {
+            de => 'Fuss',
+            en => 'feet',
+            fr => 'feet',
+            nl => 'feet',
+            pl => 'feet',
+        },
+        txt_format         => '%value%%unit_symbol%',
+        txt_format_long    => '%value% %unit_long%',
+        txt_format_long_pl => '%value% %unit_long_pl%',
+    },
+
+    yd => {
+        base_ref  => 0,
+        unit      => 'yd',
+        unit_long => {
+            de => 'Yard',
+            en => 'yard',
+            fr => 'yard',
+            nl => 'yard',
+            pl => 'yard',
+        },
+        unit_long_pl => {
+            de => 'Yards',
+            en => 'yards',
+            fr => 'yards',
+            nl => 'yards',
+            pl => 'yards',
         },
     },
 
-    "mm" => {
-        "unit_type" => 4,
-        "unit"      => "mm",
-        "unit_long" => {
-            "de" => "Millimeter",
-            "en" => "milimeter",
-            "fr" => "milimeter",
-            "nl" => "milimeter",
-            "pl" => "milimeter",
-        },
-    },
-
-    "cm" => {
-        "unit_type" => 4,
-        "unit"      => "cm",
-        "unit_long" => {
-            "de" => "Zentimeter",
-            "en" => "centimeter",
-            "fr" => "centimeter",
-            "nl" => "centimeter",
-            "pl" => "centimeter",
-        },
-    },
-
-    "in" => {
-        "unit_type"   => 4,
-        "unit_symbol" => "″",
-        "unit"        => "in",
-        "unit_long"   => {
-            "de" => "Zoll",
-            "en" => "inch",
-            "fr" => "inch",
-            "nl" => "inch",
-            "pl" => "inch",
-        },
-        "unit_long_pl" => {
-            "de" => "Zoll",
-            "en" => "inches",
-            "fr" => "inches",
-            "nl" => "inches",
-            "pl" => "inches",
-        },
-        "txt_format"         => '%value%%unit_symbol%',
-        "txt_format_long"    => '%value% %unit_long%',
-        "txt_format_long_pl" => '%value% %unit_long_pl%',
-    },
-
-    "ft" => {
-        "unit_type"   => 4,
-        "unit_symbol" => "′",
-        "unit"        => "ft",
-        "unit_long"   => {
-            "de" => "Fuss",
-            "en" => "foot",
-            "fr" => "foot",
-            "nl" => "foot",
-            "pl" => "foot",
-        },
-        "unit_long_pl" => {
-            "de" => "Fuss",
-            "en" => "feet",
-            "fr" => "feet",
-            "nl" => "feet",
-            "pl" => "feet",
-        },
-        "txt_format"         => '%value%%unit_symbol%',
-        "txt_format_long"    => '%value% %unit_long%',
-        "txt_format_long_pl" => '%value% %unit_long_pl%',
-    },
-
-    "yd" => {
-        "unit_type" => 4,
-        "unit"      => "yd",
-        "unit_long" => {
-            "de" => "Yard",
-            "en" => "yard",
-            "fr" => "yard",
-            "nl" => "yard",
-            "pl" => "yard",
-        },
-        "unit_long_pl" => {
-            "de" => "Yards",
-            "en" => "yards",
-            "fr" => "yards",
-            "nl" => "yards",
-            "pl" => "yards",
-        },
-    },
-
-    "mi" => {
-        "unit_type" => 4,
-        "unit"      => "mi",
-        "unit_long" => {
-            "de" => "Meilen",
-            "en" => "miles",
-            "fr" => "miles",
-            "nl" => "miles",
-            "pl" => "miles",
+    mi => {
+        base_ref  => 0,
+        unit      => 'mi',
+        unit_long => {
+            de => 'Meilen',
+            en => 'miles',
+            fr => 'miles',
+            nl => 'miles',
+            pl => 'miles',
         },
     },
 
     # time
-    "sec" => {
-        "unit_type" => 5,
-        "unit"      => {
-            "de" => "s",
-            "en" => "s",
-            "fr" => "s",
-            "nl" => "s",
-            "pl" => "s",
+    sec => {
+        base_ref     => 2,
+        unit_scale_t => '1',
+        unit         => {
+            de => 's',
+            en => 's',
+            fr => 's',
+            nl => 'sec',
+            pl => 'sec',
         },
-        "unit_long" => {
-            "de" => "Sekunde",
-            "en" => "second",
-            "fr" => "second",
-            "nl" => "second",
-            "pl" => "second",
+        unit_long => {
+            de => 'Sekunde',
+            en => 'second',
+            fr => 'second',
+            nl => 'second',
+            pl => 'second',
         },
-        "unit_long_pl" => {
-            "de" => "Sekunden",
-            "en" => "seconds",
-            "fr" => "seconds",
-            "nl" => "seconds",
-            "pl" => "seconds",
+        unit_long_pl => {
+            de => 'Sekunden',
+            en => 'seconds',
+            fr => 'seconds',
+            nl => 'seconds',
+            pl => 'seconds',
         },
     },
 
-    "min" => {
-        "unit_type" => 5,
-        "unit"      => {
-            "de" => "Min",
-            "en" => "min",
-            "fr" => "min",
-            "nl" => "min",
-            "pl" => "min",
+    min => {
+        base_ref     => 2,
+        unit_scale_t => '60',
+        unit         => {
+            de => 'Min',
+            en => 'min',
+            fr => 'min',
+            nl => 'min',
+            pl => 'min',
         },
-        "unit_long" => {
-            "de" => "Minute",
-            "en" => "minute",
-            "fr" => "minute",
-            "nl" => "minute",
-            "pl" => "minute",
+        unit_long => {
+            de => 'Minute',
+            en => 'minute',
+            fr => 'minute',
+            nl => 'minute',
+            pl => 'minute',
         },
-        "unit_long_pl" => {
-            "de" => "Minuten",
-            "en" => "minutes",
-            "fr" => "minutes",
-            "nl" => "minutes",
-            "pl" => "minutes",
+        unit_long_pl => {
+            de => 'Minuten',
+            en => 'minutes',
+            fr => 'minutes',
+            nl => 'minutes',
+            pl => 'minutes',
         },
     },
 
-    "hr" => {
-        "unit_type" => 5,
-        "unit"      => {
-            "de" => "Std",
-            "en" => "hr",
-            "fr" => "hr",
-            "nl" => "hr",
-            "pl" => "hr",
+    hr => {
+        base_ref     => 2,
+        unit_scale_t => '3600',
+        unit         => 'h',
+        unit_long    => {
+            de => 'Stunde',
+            en => 'hour',
+            fr => 'hour',
+            nl => 'hour',
+            pl => 'hour',
         },
-        "unit_long" => {
-            "de" => "Stunde",
-            "en" => "hour",
-            "fr" => "hour",
-            "nl" => "hour",
-            "pl" => "hour",
-        },
-        "unit_long_pl" => {
-            "de" => "Stunden",
-            "en" => "hours",
-            "fr" => "hours",
-            "nl" => "hours",
-            "pl" => "hours",
+        unit_long_pl => {
+            de => 'Stunden',
+            en => 'hours',
+            fr => 'hours',
+            nl => 'hours',
+            pl => 'hours',
         },
     },
 
-    "d" => {
-        "unit_type" => 5,
-        "unit"      => {
-            "de" => "T",
-            "en" => "d",
-            "fr" => "d",
-            "nl" => "d",
-            "pl" => "d",
+    d => {
+        base_ref     => 2,
+        unit_scale_t => '86400',
+        unit         => {
+            de => 'T',
+            en => 'd',
+            fr => 'd',
+            nl => 'd',
+            pl => 'd',
         },
-        "unit_long" => {
-            "de" => "Tag",
-            "en" => "day",
-            "fr" => "day",
-            "nl" => "day",
-            "pl" => "day",
+        unit_long => {
+            de => 'Tag',
+            en => 'day',
+            fr => 'day',
+            nl => 'day',
+            pl => 'day',
         },
-        "unit_long_pl" => {
-            "de" => "Tage",
-            "en" => "days",
-            "fr" => "days",
-            "nl" => "days",
-            "pl" => "days",
+        unit_long_pl => {
+            de => 'Tage',
+            en => 'days',
+            fr => 'days',
+            nl => 'days',
+            pl => 'days',
         },
     },
 
-    "w" => {
-        "unit_type" => 5,
-        "unit"      => {
-            "de" => "W",
-            "en" => "w",
-            "fr" => "w",
-            "nl" => "w",
-            "pl" => "w",
+    w => {
+        base_ref     => 2,
+        unit_scale_t => '604800',
+        unit         => {
+            de => 'W',
+            en => 'w',
+            fr => 'w',
+            nl => 'w',
+            pl => 'w',
         },
-        "unit_long" => {
-            "de" => "Woche",
-            "en" => "week",
-            "fr" => "week",
-            "nl" => "week",
-            "pl" => "week",
+        unit_long => {
+            de => 'Woche',
+            en => 'week',
+            fr => 'week',
+            nl => 'week',
+            pl => 'week',
         },
-        "unit_long_pl" => {
-            "de" => "Wochen",
-            "en" => "weeks",
-            "fr" => "weeks",
-            "nl" => "weeks",
-            "pl" => "weeks",
+        unit_long_pl => {
+            de => 'Wochen',
+            en => 'weeks',
+            fr => 'weeks',
+            nl => 'weeks',
+            pl => 'weeks',
         },
     },
 
-    "m" => {
-        "unit_type" => 5,
-        "unit"      => {
-            "de" => "M",
-            "en" => "m",
-            "fr" => "m",
-            "nl" => "m",
-            "pl" => "m",
+    mon => {
+        base_ref     => 2,
+        unit_scale_t => '2592000',
+        unit         => {
+            de => 'M',
+            en => 'm',
+            fr => 'm',
+            nl => 'm',
+            pl => 'm',
         },
-        "unit_long" => {
-            "de" => "Monat",
-            "en" => "month",
-            "fr" => "month",
-            "nl" => "month",
-            "pl" => "month",
+        unit_long => {
+            de => 'Monat',
+            en => 'month',
+            fr => 'month',
+            nl => 'month',
+            pl => 'month',
         },
-        "unit_long_pl" => {
-            "de" => "Monate",
-            "en" => "Monat",
-            "fr" => "Monat",
-            "nl" => "Monat",
-            "pl" => "Monat",
+        unit_long_pl => {
+            de => 'Monate',
+            en => 'Monat',
+            fr => 'Monat',
+            nl => 'Monat',
+            pl => 'Monat',
         },
     },
 
-    "y" => {
-        "unit_type" => 5,
-        "unit"      => {
-            "de" => "J",
-            "en" => "y",
-            "fr" => "y",
-            "nl" => "y",
-            "pl" => "y",
+    y => {
+        base_ref     => 2,
+        unit_scale_t => '31536000',
+        unit         => {
+            de => 'J',
+            en => 'y',
+            fr => 'y',
+            nl => 'y',
+            pl => 'y',
         },
-        "unit_long" => {
-            "de" => "Jahr",
-            "en" => "year",
-            "fr" => "year",
-            "nl" => "year",
-            "pl" => "year",
+        unit_long => {
+            de => 'Jahr',
+            en => 'year',
+            fr => 'year',
+            nl => 'year',
+            pl => 'year',
         },
-        "unit_long_pl" => {
-            "de" => "Jahre",
-            "en" => "years",
-            "fr" => "years",
-            "nl" => "years",
-            "pl" => "years",
+        unit_long_pl => {
+            de => 'Jahre',
+            en => 'years',
+            fr => 'years',
+            nl => 'years',
+            pl => 'years',
         },
     },
 
     # speed
-    "bft" => {
-        "unit_type" => 6,
-        "unit"      => "bft",
-        "unit_long" => {
-            "de" => "Windstärke",
-            "en" => "wind force",
-            "fr" => "wind force",
-            "nl" => "wind force",
-            "pl" => "wind force",
+    bft => {
+        base_ref  => 15,
+        unit      => 'bft',
+        unit_long => {
+            de => 'Windstärke',
+            en => 'wind force',
+            fr => 'wind force',
+            nl => 'wind force',
+            pl => 'wind force',
         },
-        "txt_format_long" => '%unit_long% %value%',
+        txt_format_long => '%unit_long% %value%',
     },
 
-    "fts" => {
-        "unit_type" => 6,
-        "unit"      => "ft/s",
-        "unit_long" => {
-            "de" => "Feet pro Sekunde",
-            "en" => "feets per second",
-            "fr" => "feets per second",
-            "nl" => "feets per second",
-            "pl" => "feets per second",
+    kn => {
+        base_ref  => 15,
+        unit      => 'kn',
+        unit_long => {
+            de => 'Knoten',
+            en => 'knots',
+            fr => 'knots',
+            nl => 'knots',
+            pl => 'knots',
         },
     },
 
-    "kmh" => {
-        "unit_type" => 6,
-        "unit"      => "km/h",
-        "unit_long" => {
-            "de" => "Kilometer pro Stunde",
-            "en" => "kilometer per hour",
-            "fr" => "kilometer per hour",
-            "nl" => "kilometer per hour",
-            "pl" => "kilometer per hour",
+    fts => {
+        base_ref        => 15,
+        unit_ref        => 'ft',
+        unit_ref_t      => 'sec',
+        txt_format      => '%value% %unit%/%unit_t%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    "kn" => {
-        "unit_type" => 6,
-        "unit"      => "kn",
-        "unit_long" => {
-            "de" => "Knoten",
-            "en" => "knots",
-            "fr" => "knots",
-            "nl" => "knots",
-            "pl" => "knots",
+    mph => {
+        base_ref        => 15,
+        unit_ref        => 'mi',
+        unit_ref_t      => 'hr',
+        txt_format      => '%value% %unit%/%unit_t%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    "mph" => {
-        "unit_type" => 6,
-        "unit"      => "mi/h",
-        "unit_long" => {
-            "de" => "Meilen pro Stunde",
-            "en" => "miles per hour",
-            "fr" => "miles per hour",
-            "nl" => "miles per hour",
-            "pl" => "miles per hour",
+    kmh => {
+        base_ref        => 15,
+        unit_ref        => 'm',
+        unit_ref_t      => 'hr',
+        unit_scale_m    => '1.0e3',
+        txt_format      => '%value% %unit%/%unit_t%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    "mps" => {
-        "unit_type" => 6,
-        "unit"      => "m/s",
-        "unit_long" => {
-            "de" => "Meter pro Sekunde",
-            "en" => "meter per second",
-            "fr" => "meter per second",
-            "nl" => "meter per second",
-            "pl" => "meter per second",
+    mps => {
+        base_ref        => 15,
+        unit_ref        => 'm',
+        unit_ref_t      => 'sec',
+        unit_scale_m    => '1.0e0',
+        txt_format      => '%value% %unit%/%unit_t%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
     # weight
-    "mol" => {
-        "unit_type" => 7,
-        "unit"      => "mol",
+    mol => {
+        base_ref => 5,
+        unit     => 'mol',
     },
 
-    "n" => {
-        "unit_type" => 7,
-        "unit"      => "N",
-        "unit_long" => {
-            "de" => "Newton",
-            "en" => "Newton",
-            "fr" => "Newton",
-            "nl" => "Newton",
-            "pl" => "Newton",
+    pg => {
+        unit_ref     => 'g',
+        unit_scale_m => "1.0e-12",
+    },
+
+    ng => {
+        unit_ref     => 'g',
+        unit_scale_m => "1.0e-9",
+    },
+
+    ug => {
+        unit_ref     => 'g',
+        unit_scale_m => "1.0e-6",
+    },
+
+    mg => {
+        unit_ref     => 'g',
+        unit_scale_m => "1.0e-3",
+    },
+
+    cg => {
+        unit_ref     => 'g',
+        unit_scale_m => "1.0e-2",
+    },
+
+    dg => {
+        unit_ref     => 'g',
+        unit_scale_m => "1.0e-1",
+    },
+
+    g => {
+        base_ref     => 1,
+        unit_scale_m => "1.0e0",
+        unit         => 'g',
+        unit_long    => {
+            de => 'Gramm',
+            en => 'gram',
+            fr => 'gram',
+            nl => 'gram',
+            pl => 'gram',
         },
     },
 
-    "g" => {
-        "unit_type" => 7,
-        "unit"      => "g",
-        "unit_long" => {
-            "de" => "Gramm",
-            "en" => "gram",
-            "fr" => "gram",
-            "nl" => "gram",
-            "pl" => "gram",
+    kg => {
+        unit_ref     => 'g',
+        unit_scale_m => "1.0e3",
+    },
+
+    t => {
+        unit_ref     => 'g',
+        unit_scale_m => "1.0e6",
+        unit         => 't',
+        unit_long    => {
+            de => 'Tonne',
+            en => 'ton',
+            fr => 'ton',
+            nl => 'ton',
+            pl => 'ton',
+        },
+        unit_long_pl => {
+            de => 'Tonnen',
+            en => 'tons',
+            fr => 'tons',
+            nl => 'tons',
+            pl => 'tons',
         },
     },
 
-    "dg" => {
-        "unit_type" => 7,
-        "unit"      => "dg",
-        "unit_long" => {
-            "de" => "Dekagramm",
-            "en" => "dekagram",
-            "fr" => "dekagram",
-            "nl" => "dekagram",
-            "pl" => "dekagram",
+    lb => {
+        base_ref  => 1,
+        unit      => 'lb',
+        unit_long => {
+            de => 'Pfund',
+            en => 'pound',
+            fr => 'pound',
+            nl => 'pound',
+            pl => 'pound',
         },
     },
 
-    "kg" => {
-        "unit_type" => 7,
-        "unit"      => "kg",
-        "unit_long" => {
-            "de" => "Kilogramm",
-            "en" => "kilogram",
-            "fr" => "kilogram",
-            "nl" => "kilogram",
-            "pl" => "kilogram",
+    lbs => {
+        base_ref  => 1,
+        unit      => 'lbs',
+        unit_long => {
+            de => 'Pfund',
+            en => 'pound',
+            fr => 'pound',
+            nl => 'pound',
+            pl => 'pound',
         },
     },
 
-    "t" => {
-        "unit_type" => 7,
-        "unit"      => "t",
-        "unit_long" => {
-            "de" => "Tonne",
-            "en" => "ton",
-            "fr" => "ton",
-            "nl" => "ton",
-            "pl" => "ton",
-        },
-        "unit_long_pl" => {
-            "de" => "Tonnen",
-            "en" => "tons",
-            "fr" => "tons",
-            "nl" => "tons",
-            "pl" => "tons",
+    # luminous intensity
+    cd => {
+        base_ref  => 6,
+        unit      => 'cd',
+        unit_long => {
+            de => 'Candela',
+            en => 'Candela',
+            fr => 'Candela',
+            nl => 'Candela',
+            pl => 'Candela',
         },
     },
 
-    "lb" => {
-        "unit_type" => 7,
-        "unit"      => "lb",
-        "unit_long" => {
-            "de" => "Pfund",
-            "en" => "pound",
-            "fr" => "pound",
-            "nl" => "pound",
-            "pl" => "pound",
+    # illumination intensity
+    lx => {
+        base_ref  => 16,
+        unit      => 'lx',
+        unit_long => {
+            de => 'Lux',
+            en => 'Lux',
+            fr => 'Lux',
+            nl => 'Lux',
+            pl => 'Lux',
         },
     },
 
-    "lbs" => {
-        "unit_type" => 7,
-        "unit"      => "lbs",
-        "unit_long" => {
-            "de" => "Pfund",
-            "en" => "pound",
-            "fr" => "pound",
-            "nl" => "pound",
-            "pl" => "pound",
+    # luminous flux
+    lm => {
+        base_ref  => 17,
+        unit      => 'lm',
+        unit_long => {
+            de => 'Lumen',
+            en => 'Lumen',
+            fr => 'Lumen',
+            nl => 'Lumen',
+            pl => 'Lumen',
         },
     },
 
-    # solar
-    "cd" => {
-        "unit_type" => 8,
-        "unit"      => "cd",
-        "unit_long" => {
-            "de" => "Candela",
-            "en" => "Candela",
-            "fr" => "Candela",
-            "nl" => "Candela",
-            "pl" => "Candela",
+    uvi => {
+        unit      => 'UVI',
+        unit_long => {
+            de => 'UV-Index',
+            en => 'UV-Index',
+            fr => 'UV-Index',
+            nl => 'UV-Index',
+            pl => 'UV-Index',
         },
-    },
-
-    "lx" => {
-        "unit_type" => 8,
-        "unit"      => "lx",
-        "unit_long" => {
-            "de" => "Lux",
-            "en" => "Lux",
-            "fr" => "Lux",
-            "nl" => "Lux",
-            "pl" => "Lux",
-        },
-    },
-
-    "lm" => {
-        "unit_type" => 8,
-        "unit"      => "lm",
-        "unit_long" => {
-            "de" => "Lumen",
-            "en" => "Lumen",
-            "fr" => "Lumen",
-            "nl" => "Lumen",
-            "pl" => "Lumen",
-        },
-    },
-
-    "uvi" => {
-        "unit_type" => 8,
-        "unit"      => "UVI",
-        "unit_long" => {
-            "de" => "UV-Index",
-            "en" => "UV-Index",
-            "fr" => "UV-Index",
-            "nl" => "UV-Index",
-            "pl" => "UV-Index",
-        },
-        "txt_format"         => '%unit% %value%',
-        "txt_format_long"    => '%unit_long% %value%',
-        "txt_format_long_pl" => '%unit_long% %value%',
+        txt_format         => '%unit% %value%',
+        txt_format_long    => '%unit_long% %value%',
+        txt_format_long_pl => '%unit_long% %value%',
     },
 
     # volume
-    "ml" => {
-        "unit_type" => 9,
-        "unit"      => "ml",
-        "unit_long" => {
-            "de" => "Milliliter",
-            "en" => "mililitre",
-            "fr" => "mililitre",
-            "nl" => "mililitre",
-            "pl" => "mililitre",
+    cm3 => {
+        base_ref      => 18,
+        unit_ref      => 'm',
+        unit_scale_cu => '1.0e-2',
+    },
+
+    m3 => {
+        base_ref      => 18,
+        unit_ref      => 'm',
+        unit_scale_cu => '1.0e0',
+    },
+
+    ml => {
+        unit_ref     => 'l',
+        unit_scale_m => '1.0e-3',
+    },
+
+    l => {
+        base_ref  => 18,
+        unit      => 'l',
+        unit_long => {
+            de => 'Liter',
+            en => 'liter',
+            fr => 'liter',
+            nl => 'liter',
+            pl => 'liter',
         },
-        "unit_long_pl" => {
-            "de" => "Milliliter",
-            "en" => "mililitres",
-            "fr" => "mililitres",
-            "nl" => "mililitres",
-            "pl" => "mililitres",
+        unit_long_pl => {
+            de => 'Liter',
+            en => 'liters',
+            fr => 'liters',
+            nl => 'liters',
+            pl => 'liters',
         },
     },
 
-    "l" => {
-        "unit_type" => 9,
-        "unit"      => "l",
-        "unit_long" => {
-            "de" => "Liter",
-            "en" => "litre",
-            "fr" => "litre",
-            "nl" => "litre",
-            "pl" => "litre",
-        },
-        "unit_long_pl" => {
-            "de" => "Liter",
-            "en" => "litres",
-            "fr" => "litres",
-            "nl" => "litres",
-            "pl" => "litres",
+    hl => {
+        unit_ref     => 'l',
+        unit_scale_m => '1.0e2',
+    },
+
+    b => {
+        base_ref     => 19,
+        unit_scale_m => '1.0e0',
+        unit         => 'B',
+        unit_long    => {
+            de => 'Bel',
+            en => 'Bel',
+            fr => 'Bel',
+            nl => 'Bel',
+            pl => 'Bel',
         },
     },
 
-    "oz" => {
-        "unit_type" => 9,
-        "unit"      => "oz",
-        "unit_long" => {
-            "de" => "Unze",
-            "en" => "ounce",
-            "fr" => "ounce",
-            "nl" => "ounce",
-            "pl" => "ounce",
-        },
-        "unit_long_pl" => {
-            "de" => "Unzen",
-            "en" => "ounces",
-            "fr" => "ounces",
-            "nl" => "ounces",
-            "pl" => "ounces",
+    db => {
+        unit_ref     => 'b',
+        unit_scale_m => '1.0e-1',
+    },
+
+    ua => {
+        unit_ref     => 'a',
+        unit_scale_m => '1.0e-6',
+    },
+
+    ma => {
+        unit_ref     => 'a',
+        unit_scale_m => '1.0e-3',
+    },
+
+    a => {
+        base_ref     => 3,
+        unit_scale_m => '1.0e0',
+        unit         => 'A',
+        unit_long    => {
+            de => 'Ampere',
+            en => 'Ampere',
+            fr => 'Ampere',
+            nl => 'Ampere',
+            pl => 'Ampere',
         },
     },
 
-    "floz" => {
-        "unit_type" => 9,
-        "unit"      => "fl oz",
-        "unit_long" => {
-            "de" => "fl. Unze",
-            "en" => "fl. ounce",
-            "fr" => "fl. ounce",
-            "nl" => "fl. ounce",
-            "pl" => "fl. ounce",
-        },
-        "unit_long_pl" => {
-            "de" => "fl. Unzen",
-            "en" => "fl. ounces",
-            "fr" => "fl. ounces",
-            "nl" => "fl. ounces",
-            "pl" => "fl. ounces",
+    uv => {
+        unit_ref     => 'v',
+        unit_scale_m => '1.0e-6',
+    },
+
+    mv => {
+        unit_ref     => 'v',
+        unit_scale_m => '1.0e-3',
+    },
+
+    v => {
+        base_ref     => 13,
+        unit_scale_m => '1.0e0',
+        unit         => 'V',
+        unit_long    => {
+            de => 'Volt',
+            en => 'Volt',
+            fr => 'Volt',
+            nl => 'Volt',
+            pl => 'Volt',
         },
     },
 
-    "ozfl" => {
-        "unit_type" => 9,
-        "unit"      => "fl oz",
-        "unit_long" => {
-            "de" => "fl. Unze",
-            "en" => "fl. ounce",
-            "fr" => "fl. ounce",
-            "nl" => "fl. ounce",
-            "pl" => "fl. ounce",
-        },
-        "unit_long_pl" => {
-            "de" => "fl. Unzen",
-            "en" => "fl. ounces",
-            "fr" => "fl. ounces",
-            "nl" => "fl. ounces",
-            "pl" => "fl. ounces",
+    uj => {
+        unit_ref     => 'j',
+        unit_scale_m => '1.0e-6',
+    },
+
+    mj => {
+        unit_ref     => 'j',
+        unit_scale_m => '1.0e-3',
+    },
+
+    j => {
+        base_ref     => 7,
+        unit_scale_m => '1.0e0',
+        unit         => 'J',
+        unit_long    => {
+            de => 'Joule',
+            en => 'Joule',
+            fr => 'Joule',
+            nl => 'Joule',
+            pl => 'Joule',
         },
     },
 
-    "quart" => {
-        "unit_type" => 9,
-        "unit"      => "quart",
-        "unit_long" => {
-            "de" => "Quart",
-            "en" => "quart",
-            "fr" => "quart",
-            "nl" => "quart",
-            "pl" => "quart",
-        },
-        "unit_long_pl" => {
-            "de" => "Quarts",
-            "en" => "quarts",
-            "fr" => "quarts",
-            "nl" => "quarts",
-            "pl" => "quarts",
+    uw => {
+        unit_ref     => 'j',
+        unit_scale_m => '1.0e-6',
+    },
+
+    mw => {
+        unit_ref     => 'j',
+        unit_scale_m => '1.0e-3',
+    },
+
+    w => {
+        base_ref     => 9,
+        unit_scale_m => '1.0e0',
+        unit         => 'Watt',
+        unit_long    => {
+            de => 'Watt',
+            en => 'Watt',
+            fr => 'Watt',
+            nl => 'Watt',
+            pl => 'Watt',
         },
     },
 
-    "gallon" => {
-        "unit_type" => 9,
-        "unit"      => "gallon",
-        "unit_long" => {
-            "de" => "Gallone",
-            "en" => "gallon",
-            "fr" => "gallon",
-            "nl" => "gallon",
-            "pl" => "gallon",
+    va => {
+        unit_ref => 'w',
+    },
+
+    uwpscm => {
+        unit_ref        => 'w',
+        unit_scale_m    => '1.0e-6',
+        unit_ref_sq     => 'm',
+        unit_scale_sq   => '1.0e-2',
+        txt_format      => '%value% %unit%/%unit_sq%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
         },
-        "unit_long_pl" => {
-            "de" => "Gallonen",
-            "en" => "gallons",
-            "fr" => "gallons",
-            "nl" => "gallons",
-            "pl" => "gallons",
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    # energy
-    "b" => {
-        "unit_type" => 10,
-        "unit"      => "B",
-        "unit_long" => {
-            "de" => "Bel",
-            "en" => "Bel",
-            "fr" => "Bel",
-            "nl" => "Bel",
-            "pl" => "Bel",
+    uwpsm => {
+        unit_ref        => 'w',
+        unit_scale_m    => '1.0e-6',
+        unit_ref_sq     => 'm',
+        unit_scale_sq   => '1.0e0',
+        txt_format      => '%value% %unit%/%unit_sq%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    "db" => {
-        "unit_type" => 10,
-        "unit"      => "dB",
-        "unit_long" => {
-            "de" => "Dezibel",
-            "en" => "Decibel",
-            "fr" => "Decibel",
-            "nl" => "Decibel",
-            "pl" => "Decibel",
+    mwpscm => {
+        unit_ref        => 'w',
+        unit_scale_m    => '1.0e-3',
+        unit_ref_sq     => 'm',
+        unit_scale_sq   => '1.0e-2',
+        txt_format      => '%value% %unit%/%unit_sq%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    "uwpscm" => {
-        "unit_type" => 10,
-        "unit"      => "uW/cm2",
-        "unit_long" => {
-            "de" => "Micro-Watt pro Quadratzentimeter",
-            "en" => "Micro-Watt per square centimeter",
-            "fr" => "Micro-Watt per square centimeter",
-            "nl" => "Micro-Watt per square centimeter",
-            "pl" => "Micro-Watt per square centimeter",
+    mwpsm => {
+        unit_ref        => 'w',
+        unit_scale_m    => '1.0e-3',
+        unit_ref_sq     => 'm',
+        unit_scale_sq   => '1.0e0',
+        txt_format      => '%value% %unit%/%unit_sq%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    "wpsm" => {
-        "unit_type" => 10,
-        "unit"      => "W/m2",
-        "unit_long" => {
-            "de" => "Watt pro Quadratmeter",
-            "en" => "Watt per square meter",
-            "fr" => "Watt per square meter",
-            "nl" => "Watt per square meter",
-            "pl" => "Watt per square meter",
+    wpscm => {
+        unit_ref        => 'w',
+        unit_scale_m    => '1.0e0',
+        unit_ref_sq     => 'm',
+        unit_scale_sq   => '1.0e-2',
+        txt_format      => '%value% %unit%/%unit_sq%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    "a" => {
-        "unit_type" => 10,
-        "unit"      => "A",
-        "unit_long" => {
-            "de" => "Ampere",
-            "en" => "Ampere",
-            "fr" => "Ampere",
-            "nl" => "Ampere",
-            "pl" => "Ampere",
+    wpsm => {
+        unit_ref        => 'w',
+        unit_scale_m    => '1.0e0',
+        unit_ref_sq     => 'm',
+        unit_scale_sq   => '1.0e0',
+        txt_format      => '%value% %unit%/%unit_sq%',
+        txt_format_long => {
+            de => '%value% %unit_long% pro %unit_long_t%',
+            en => '%value% %unit_long% per %unit_long_t%',
+            fr => '%value% %unit_long% per %unit_long_t%',
+            nl => '%value% %unit_long% per %unit_long_t%',
+            pl => '%value% %unit_long% per %unit_long_t%',
+        },
+        txt_format_long_pl => {
+            de => '%value% %unit_long_pl% pro %unit_long_t%',
+            en => '%value% %unit_long_pl% per %unit_long_t%',
+            fr => '%value% %unit_long_pl% per %unit_long_t%',
+            nl => '%value% %unit_long_pl% per %unit_long_t%',
+            pl => '%value% %unit_long_pl% per %unit_long_t%',
         },
     },
 
-    "v" => {
-        "unit_type" => 10,
-        "unit"      => "V",
-        "unit_long" => {
-            "de" => "Volt",
-            "en" => "Volt",
-            "fr" => "Volt",
-            "nl" => "Volt",
-            "pl" => "Volt",
+    coul => {
+        base_ref  => 20,
+        unit      => 'C',
+        unit_long => {
+            de => 'Coulomb',
+            en => 'Coulomb',
+            fr => 'Coulomb',
+            nl => 'Coulomb',
+            pl => 'Coulomb',
         },
     },
 
-    "w" => {
-        "unit_type" => 10,
-        "unit"      => "Watt",
-        "unit_long" => {
-            "de" => "Watt",
-            "en" => "Watt",
-            "fr" => "Watt",
-            "nl" => "Watt",
-            "pl" => "Watt",
+    far => {
+        base_ref  => 21,
+        unit      => 'F',
+        unit_long => {
+            de => 'Farad',
+            en => 'Farad',
+            fr => 'Farad',
+            nl => 'Farad',
+            pl => 'Farad',
         },
     },
 
-    "j" => {
-        "unit_type" => 10,
-        "unit"      => "J",
-        "unit_long" => {
-            "de" => "Joule",
-            "en" => "Joule",
-            "fr" => "Joule",
-            "nl" => "Joule",
-            "pl" => "Joule",
-        },
-    },
-
-    "coul" => {
-        "unit_type" => 10,
-        "unit"      => "C",
-        "unit_long" => {
-            "de" => "Coulomb",
-            "en" => "Coulomb",
-            "fr" => "Coulomb",
-            "nl" => "Coulomb",
-            "pl" => "Coulomb",
-        },
-    },
-
-    "far" => {
-        "unit_type" => 10,
-        "unit"      => "F",
-        "unit_long" => {
-            "de" => "Farad",
-            "en" => "Farad",
-            "fr" => "Farad",
-            "nl" => "Farad",
-            "pl" => "Farad",
-        },
-    },
-
-    "ohm" => {
-        "unit_type" => 10,
-        "unit"      => "Ω",
-        "unit_long" => {
-            "de" => "Ohm",
-            "en" => "Ohm",
-            "fr" => "Ohm",
-            "nl" => "Ohm",
-            "pl" => "Ohm",
-        },
-    },
-
-    "s" => {
-        "unit_type" => 10,
-        "unit"      => "S",
-        "unit_long" => {
-            "de" => "Siemens",
-            "en" => "Siemens",
-            "fr" => "Siemens",
-            "nl" => "Siemens",
-            "pl" => "Siemens",
-        },
-    },
-
-    "wb" => {
-        "unit_type" => 10,
-        "unit"      => "Wb",
-        "unit_long" => {
-            "de" => "Weber",
-            "en" => "Weber",
-            "fr" => "Weber",
-            "nl" => "Weber",
-            "pl" => "Weber",
-        },
-    },
-
-    "t" => {
-        "unit_type" => 10,
-        "unit"      => "T",
-        "unit_long" => {
-            "de" => "Tesla",
-            "en" => "Tesla",
-            "fr" => "Tesla",
-            "nl" => "Tesla",
-            "pl" => "Tesla",
-        },
-    },
-
-    "h" => {
-        "unit_type" => 10,
-        "unit"      => "H",
-        "unit_long" => {
-            "de" => "Henry",
-            "en" => "Henry",
-            "fr" => "Henry",
-            "nl" => "Henry",
-            "pl" => "Henry",
-        },
-    },
-
-    "bq" => {
-        "unit_type" => 10,
-        "unit"      => "Bq",
-        "unit_long" => {
-            "de" => "Becquerel",
-            "en" => "Becquerel",
-            "fr" => "Becquerel",
-            "nl" => "Becquerel",
-            "pl" => "Becquerel",
-        },
-    },
-
-    "gy" => {
-        "unit_type" => 10,
-        "unit"      => "Gy",
-        "unit_long" => {
-            "de" => "Gray",
-            "en" => "Gray",
-            "fr" => "Gray",
-            "nl" => "Gray",
-            "pl" => "Gray",
-        },
-    },
-
-    "sv" => {
-        "unit_type" => 10,
-        "unit"      => "Sv",
-        "unit_long" => {
-            "de" => "Sievert",
-            "en" => "Sievert",
-            "fr" => "Sievert",
-            "nl" => "Sievert",
-            "pl" => "Sievert",
-        },
-    },
-
-    "kat" => {
-        "unit_type" => 10,
-        "unit"      => "kat",
-        "unit_long" => {
-            "de" => "Katal",
-            "en" => "Katal",
-            "fr" => "Katal",
-            "nl" => "Katal",
-            "pl" => "Katal",
+    ohm => {
+        base_ref    => 22,
+        unit_symbol => 'Ω',
+        unit        => 'Ohm',
+        unit_long   => {
+            de => 'Ohm',
+            en => 'Ohm',
+            fr => 'Ohm',
+            nl => 'Ohm',
+            pl => 'Ohm',
         },
     },
 
 );
 
 my %readingsDB = (
-    "airpress" => {
-        "unified" => "pressure_hpa",    # link only
+    airpress => {
+        unified => 'pressure_hpa',    # link only
     },
-    "azimuth" => {
-        "short" => "AZ",
-        "unit"  => "deg",
+    azimuth => {
+        short => 'AZ',
+        unit  => 'gon',
     },
-    "compasspoint" => {
-        "short" => "CP",
+    compasspoint => {
+        short => 'CP',
     },
-    "dewpoint" => {
-        "unified" => "dewpoint_c",      # link only
+    dewpoint => {
+        unified => 'dewpoint_c',      # link only
     },
-    "dewpoint_c" => {
-        "short" => "D",
-        "unit"  => "c",
+    dewpoint_c => {
+        short => 'D',
+        unit  => 'c',
     },
-    "dewpoint_f" => {
-        "short" => "Df",
-        "unit"  => "f",
+    dewpoint_f => {
+        short => 'Df',
+        unit  => 'f',
     },
-    "dewpoint_k" => {
-        "short" => "Dk",
-        "unit"  => "k",
+    dewpoint_k => {
+        short => 'Dk',
+        unit  => 'k',
     },
-    "elevation" => {
-        "short" => "EL",
-        "unit"  => "deg",
+    elevation => {
+        short => 'EL',
+        unit  => 'gon',
     },
-    "feelslike" => {
-        "unified" => "feelslike_c",    # link only
+    feelslike => {
+        unified => 'feelslike_c',    # link only
     },
-    "feelslike_c" => {
-        "short" => "Tf",
-        "unit"  => "c",
+    feelslike_c => {
+        short => 'Tf',
+        unit  => 'c',
     },
-    "feelslike_f" => {
-        "short" => "Tff",
-        "unit"  => "f",
+    feelslike_f => {
+        short => 'Tff',
+        unit  => 'f',
     },
-    "heat_index" => {
-        "unified" => "heat_index_c",    # link only
+    heat_index => {
+        unified => 'heat_index_c',    # link only
     },
-    "heat_index_c" => {
-        "short" => "HI",
-        "unit"  => "c",
+    heat_index_c => {
+        short => 'HI',
+        unit  => 'c',
     },
-    "heat_index_f" => {
-        "short" => "HIf",
-        "unit"  => "f",
+    heat_index_f => {
+        short => 'HIf',
+        unit  => 'f',
     },
-    "high" => {
-        "unified" => "high_c",          # link only
+    high => {
+        unified => 'high_c',          # link only
     },
-    "high_c" => {
-        "short" => "Th",
-        "unit"  => "c",
+    high_c => {
+        short => 'Th',
+        unit  => 'c',
     },
-    "high_f" => {
-        "short" => "Thf",
-        "unit"  => "f",
+    high_f => {
+        short => 'Thf',
+        unit  => 'f',
     },
-    "humidity" => {
-        "short" => "H",
-        "unit"  => "pct",
+    humidity => {
+        short => 'H',
+        unit  => 'pct',
     },
-    "humidityabs" => {
-        "unified" => "humidityabs_c",    # link only
+    humidityabs => {
+        unified => 'humidityabs_c',    # link only
     },
-    "humidityabs_c" => {
-        "short" => "Ha",
-        "unit"  => "c",
+    humidityabs_c => {
+        short => 'Ha',
+        unit  => 'c',
     },
-    "humidityabs_f" => {
-        "short" => "Haf",
-        "unit"  => "f",
+    humidityabs_f => {
+        short => 'Haf',
+        unit  => 'f',
     },
-    "humidityabs_k" => {
-        "short" => "Hak",
-        "unit"  => "k",
+    humidityabs_k => {
+        short => 'Hak',
+        unit  => 'k',
     },
-    "horizon" => {
-        "short" => "HORIZ",
-        "unit"  => "deg",
+    horizon => {
+        short => 'HORIZ',
+        unit  => 'gon',
     },
-    "indoordewpoint" => {
-        "unified" => "indoordewpoint_c",    # link only
+    indoordewpoint => {
+        unified => 'indoordewpoint_c',    # link only
     },
-    "indoordewpoint_c" => {
-        "short" => "Di",
-        "unit"  => "c",
+    indoordewpoint_c => {
+        short => 'Di',
+        unit  => 'c',
     },
-    "indoordewpoint_f" => {
-        "short" => "Dif",
-        "unit"  => "f",
+    indoordewpoint_f => {
+        short => 'Dif',
+        unit  => 'f',
     },
-    "indoordewpoint_k" => {
-        "short" => "Dik",
-        "unit"  => "k",
+    indoordewpoint_k => {
+        short => 'Dik',
+        unit  => 'k',
     },
-    "indoorhumidity" => {
-        "short" => "Hi",
-        "unit"  => "pct",
+    indoorhumidity => {
+        short => 'Hi',
+        unit  => 'pct',
     },
-    "indoorhumidityabs" => {
-        "unified" => "indoorhumidityabs_c",    # link only
+    indoorhumidityabs => {
+        unified => 'indoorhumidityabs_c',    # link only
     },
-    "indoorhumidityabs_c" => {
-        "short" => "Hai",
-        "unit"  => "c",
+    indoorhumidityabs_c => {
+        short => 'Hai',
+        unit  => 'c',
     },
-    "indoorhumidityabs_f" => {
-        "short" => "Haif",
-        "unit"  => "f",
+    indoorhumidityabs_f => {
+        short => 'Haif',
+        unit  => 'f',
     },
-    "indoorhumidityabs_k" => {
-        "short" => "Haik",
-        "unit"  => "k",
+    indoorhumidityabs_k => {
+        short => 'Haik',
+        unit  => 'k',
     },
-    "indoortemperature" => {
-        "unified" => "indoortemperature_c",    # link only
+    indoortemperature => {
+        unified => 'indoortemperature_c',    # link only
     },
-    "indoortemperature_c" => {
-        "short" => "Ti",
-        "unit"  => "c",
+    indoortemperature_c => {
+        short => 'Ti',
+        unit  => 'c',
     },
-    "indoortemperature_f" => {
-        "short" => "Tif",
-        "unit"  => "f",
+    indoortemperature_f => {
+        short => 'Tif',
+        unit  => 'f',
     },
-    "indoortemperature_k" => {
-        "short" => "Tik",
-        "unit"  => "k",
+    indoortemperature_k => {
+        short => 'Tik',
+        unit  => 'k',
     },
-    "israining" => {
-        "short" => "IR",
+    israining => {
+        short => 'IR',
     },
-    "level" => {
-        "short" => "LVL",
-        "unit"  => "pct",
+    level => {
+        short => 'LVL',
+        unit  => 'pct',
     },
-    "low" => {
-        "unified" => "low_c",    # link only
+    low => {
+        unified => 'low_c',    # link only
     },
-    "low_c" => {
-        "short" => "Tl",
-        "unit"  => "c",
+    low_c => {
+        short => 'Tl',
+        unit  => 'c',
     },
-    "low_f" => {
-        "short" => "Tlf",
-        "unit"  => "f",
+    low_f => {
+        short => 'Tlf',
+        unit  => 'f',
     },
-    "luminosity" => {
-        "short" => "L",
-        "unit"  => "lx",
+    luminosity => {
+        short => 'L',
+        unit  => 'lx',
     },
-    "pct" => {
-        "short" => "PCT",
-        "unit"  => "pct",
+    pct => {
+        short => 'PCT',
+        unit  => 'pct',
     },
-    "pressure" => {
-        "unified" => "pressure_hpa",    # link only
+    pressure => {
+        unified => 'pressure_hpa',    # link only
     },
-    "pressure_hpa" => {
-        "short" => "P",
-        "unit"  => "hpa",
+    pressure_hpa => {
+        short => 'P',
+        unit  => 'hpamb',
     },
-    "pressure_in" => {
-        "short" => "Pin",
-        "unit"  => "inhg",
+    pressure_in => {
+        short => 'Pin',
+        unit  => 'inhg',
     },
-    "pressure_mm" => {
-        "short" => "Pmm",
-        "unit"  => "mmhg",
+    pressure_mm => {
+        short => 'Pmm',
+        unit  => 'mmhg',
     },
-    "pressure_psi" => {
-        "short" => "Ppsi",
-        "unit"  => "psi",
+    pressure_psi => {
+        short => 'Ppsi',
+        unit  => 'psi',
     },
-    "pressure_psig" => {
-        "short" => "Ppsi",
-        "unit"  => "psig",
+    pressure_psig => {
+        short => 'Ppsi',
+        unit  => 'psig',
     },
-    "pressureabs" => {
-        "unified" => "pressureabs_hpa",    # link only
+    pressureabs => {
+        unified => 'pressureabs_hpamb',    # link only
     },
-    "pressureabs_hpa" => {
-        "short" => "Pa",
-        "unit"  => "hpa",
+    pressureabs_hpa => {
+        short => 'Pa',
+        unit  => 'hpamb',
     },
-    "pressureabs_in" => {
-        "short" => "Pain",
-        "unit"  => "inhg",
+    pressureabs_in => {
+        short => 'Pain',
+        unit  => 'inhg',
     },
-    "pressureabs_mm" => {
-        "short" => "Pamm",
-        "unit"  => "mmhg",
+    pressureabs_mm => {
+        short => 'Pamm',
+        unit  => 'mmhg',
     },
-    "pressureabs_psi" => {
-        "short" => "Ppsia",
-        "unit"  => "psia",
+    pressureabs_psi => {
+        short => 'Ppsia',
+        unit  => 'psia',
     },
-    "pressureabs_psia" => {
-        "short" => "Ppsia",
-        "unit"  => "psia",
+    pressureabs_psia => {
+        short => 'Ppsia',
+        unit  => 'psia',
     },
-    "rain" => {
-        "unified" => "rain_mm",    # link only
+    rain => {
+        unified => 'rain_mm',    # link only
     },
-    "rain_mm" => {
-        "short" => "R",
-        "unit"  => "mm",
+    rain_mm => {
+        short => 'R',
+        unit  => 'mm',
     },
-    "rain_in" => {
-        "short" => "Rin",
-        "unit"  => "in",
+    rain_in => {
+        short => 'Rin',
+        unit  => 'in',
     },
-    "rain_day" => {
-        "unified" => "rain_day_mm",    # link only
+    rain_day => {
+        unified => 'rain_day_mm',    # link only
     },
-    "rain_day_mm" => {
-        "short" => "Rd",
-        "unit"  => "mm",
+    rain_day_mm => {
+        short => 'Rd',
+        unit  => 'mm',
     },
-    "rain_day_in" => {
-        "short" => "Rdin",
-        "unit"  => "in",
+    rain_day_in => {
+        short => 'Rdin',
+        unit  => 'in',
     },
-    "rain_night" => {
-        "unified" => "rain_night_mm",    # link only
+    rain_night => {
+        unified => 'rain_night_mm',    # link only
     },
-    "rain_night_mm" => {
-        "short" => "Rn",
-        "unit"  => "mm",
+    rain_night_mm => {
+        short => 'Rn',
+        unit  => 'mm',
     },
-    "rain_night_in" => {
-        "short" => "Rnin",
-        "unit"  => "in",
+    rain_night_in => {
+        short => 'Rnin',
+        unit  => 'in',
     },
-    "rain_week" => {
-        "unified" => "rain_week_mm",     # link only
+    rain_week => {
+        unified => 'rain_week_mm',     # link only
     },
-    "rain_week_mm" => {
-        "short" => "Rw",
-        "unit"  => "mm",
+    rain_week_mm => {
+        short => 'Rw',
+        unit  => 'mm',
     },
-    "rain_week_in" => {
-        "short" => "Rwin",
-        "unit"  => "in",
+    rain_week_in => {
+        short => 'Rwin',
+        unit  => 'in',
     },
-    "rain_month" => {
-        "unified" => "rain_month_mm",    # link only
+    rain_month => {
+        unified => 'rain_month_mm',    # link only
     },
-    "rain_month_mm" => {
-        "short" => "Rm",
-        "unit"  => "mm",
+    rain_month_mm => {
+        short => 'Rm',
+        unit  => 'mm',
     },
-    "rain_month_in" => {
-        "short" => "Rmin",
-        "unit"  => "in",
+    rain_month_in => {
+        short => 'Rmin',
+        unit  => 'in',
     },
-    "rain_year" => {
-        "unified" => "rain_year_mm",     # link only
+    rain_year => {
+        unified => 'rain_year_mm',     # link only
     },
-    "rain_year_mm" => {
-        "short" => "Ry",
-        "unit"  => "mm",
+    rain_year_mm => {
+        short => 'Ry',
+        unit  => 'mm',
     },
-    "rain_year_in" => {
-        "short" => "Ryin",
-        "unit"  => "in",
+    rain_year_in => {
+        short => 'Ryin',
+        unit  => 'in',
     },
-    "snow" => {
-        "unified" => "snow_cm",          # link only
+    snow => {
+        unified => 'snow_cm',          # link only
     },
-    "snow_cm" => {
-        "short" => "S",
-        "unit"  => "cm",
+    snow_cm => {
+        short => 'S',
+        unit  => 'cm',
     },
-    "snow_in" => {
-        "short" => "Sin",
-        "unit"  => "in",
+    snow_in => {
+        short => 'Sin',
+        unit  => 'in',
     },
-    "snow_day" => {
-        "unified" => "snow_day_cm",      # link only
+    snow_day => {
+        unified => 'snow_day_cm',      # link only
     },
-    "snow_day_cm" => {
-        "short" => "Sd",
-        "unit"  => "cm",
+    snow_day_cm => {
+        short => 'Sd',
+        unit  => 'cm',
     },
-    "snow_day_in" => {
-        "short" => "Sdin",
-        "unit"  => "in",
+    snow_day_in => {
+        short => 'Sdin',
+        unit  => 'in',
     },
-    "snow_night" => {
-        "unified" => "snow_night_cm",    # link only
+    snow_night => {
+        unified => 'snow_night_cm',    # link only
     },
-    "snow_night_cm" => {
-        "short" => "Sn",
-        "unit"  => "cm",
+    snow_night_cm => {
+        short => 'Sn',
+        unit  => 'cm',
     },
-    "snow_night_in" => {
-        "short" => "Snin",
-        "unit"  => "in",
+    snow_night_in => {
+        short => 'Snin',
+        unit  => 'in',
     },
-    "sunshine" => {
-        "unified" => "solarradiation",    # link only
+    sunshine => {
+        unified => 'solarradiation',    # link only
     },
-    "solarradiation" => {
-        "short" => "SR",
-        "unit"  => "wpsm",
+    solarradiation => {
+        short => 'SR',
+        unit  => 'wpsm',
     },
-    "temp" => {
-        "unified" => "temperature_c",     # link only
+    temp => {
+        unified => 'temperature_c',     # link only
     },
-    "temp_c" => {
-        "unified" => "temperature_c",     # link only
+    temp_c => {
+        unified => 'temperature_c',     # link only
     },
-    "temp_f" => {
-        "unified" => "temperature_f",     # link only
+    temp_f => {
+        unified => 'temperature_f',     # link only
     },
-    "temp_k" => {
-        "unified" => "temperature_k",     # link only
+    temp_k => {
+        unified => 'temperature_k',     # link only
     },
-    "temperature" => {
-        "unified" => "temperature_c",     # link only
+    temperature => {
+        unified => 'temperature_c',     # link only
     },
-    "temperature_c" => {
-        "short" => "T",
-        "unit"  => "c",
+    temperature_c => {
+        short => 'T',
+        unit  => 'c',
     },
-    "temperature_f" => {
-        "short" => "Tf",
-        "unit"  => "f",
+    temperature_f => {
+        short => 'Tf',
+        unit  => 'f',
     },
-    "temperature_k" => {
-        "short" => "Tk",
-        "unit"  => "k",
+    temperature_k => {
+        short => 'Tk',
+        unit  => 'k',
     },
-    "uv" => {
-        "unified" => "uvi",    # link only
+    uv => {
+        unified => 'uvi',    # link only
     },
-    "uvi" => {
-        "short" => "UV",
-        "unit"  => "uvi",
+    uvi => {
+        short => 'UV',
+        unit  => 'uvi',
     },
-    "uvr" => {
-        "short" => "UVR",
-        "unit"  => "uwpscm",
+    uvr => {
+        short => 'UVR',
+        unit  => 'uwpscm',
     },
-    "valvedesired" => {
-        "unified" => "valve",    # link only
+    valvedesired => {
+        unified => 'valve',    # link only
     },
-    "valvepos" => {
-        "unified" => "valve",    # link only
+    valvepos => {
+        unified => 'valve',    # link only
     },
-    "valveposition" => {
-        "unified" => "valve",    # link only
+    valveposition => {
+        unified => 'valve',    # link only
     },
-    "valvepostc" => {
-        "unified" => "valve",    # link only
+    valvepostc => {
+        unified => 'valve',    # link only
     },
-    "valve" => {
-        "short" => "VAL",
-        "unit"  => "pct",
+    valve => {
+        short => 'VAL',
+        unit  => 'pct',
     },
-    "visibility" => {
-        "unified" => "visibility_km",    # link only
+    visibility => {
+        unified => 'visibility_km',    # link only
     },
-    "visibility_km" => {
-        "short" => "V",
-        "unit"  => "km",
+    visibility_km => {
+        short => 'V',
+        unit  => 'km',
     },
-    "visibility_mi" => {
-        "short" => "Vmi",
-        "unit"  => "mi",
+    visibility_mi => {
+        short => 'Vmi',
+        unit  => 'mi',
     },
-    "wind_chill" => {
-        "unified" => "wind_chill_c",     # link only
+    wind_chill => {
+        unified => 'wind_chill_c',     # link only
     },
-    "wind_chill_c" => {
-        "short" => "Wc",
-        "unit"  => "c",
+    wind_chill_c => {
+        short => 'Wc',
+        unit  => 'c',
     },
-    "wind_chill_f" => {
-        "short" => "Wcf",
-        "unit"  => "f",
+    wind_chill_f => {
+        short => 'Wcf',
+        unit  => 'f',
     },
-    "wind_chill_k" => {
-        "short" => "Wck",
-        "unit"  => "k",
+    wind_chill_k => {
+        short => 'Wck',
+        unit  => 'k',
     },
-    "wind_compasspoint" => {
-        "short" => "Wdc",
+    wind_compasspoint => {
+        short => 'Wdc',
     },
-    "windspeeddirection" => {
-        "unified" => "wind_compasspoint",    # link only
+    windspeeddirection => {
+        unified => 'wind_compasspoint',    # link only
     },
-    "winddirectiontext" => {
-        "unified" => "wind_compasspoint",    # link only
+    winddirectiontext => {
+        unified => 'wind_compasspoint',    # link only
     },
-    "wind_direction" => {
-        "short" => "Wd",
-        "unit"  => "deg",
+    wind_direction => {
+        short => 'Wd',
+        unit  => 'gon',
     },
-    "wind_dir" => {
-        "unified" => "wind_direction",       # link only
+    wind_dir => {
+        unified => 'wind_direction',       # link only
     },
-    "winddir" => {
-        "unified" => "wind_direction",       # link only
+    winddir => {
+        unified => 'wind_direction',       # link only
     },
-    "winddirection" => {
-        "unified" => "wind_direction",       # link only
+    winddirection => {
+        unified => 'wind_direction',       # link only
     },
-    "wind_gust" => {
-        "unified" => "wind_gust_kmh",        # link only
+    wind_gust => {
+        unified => 'wind_gust_kmh',        # link only
     },
-    "wind_gust_kmh" => {
-        "short" => "Wg",
-        "unit"  => "kmh",
+    wind_gust_kmh => {
+        short => 'Wg',
+        unit  => 'kmh',
     },
-    "wind_gust_bft" => {
-        "short" => "Wgbft",
-        "unit"  => "bft",
+    wind_gust_bft => {
+        short => 'Wgbft',
+        unit  => 'bft',
     },
-    "wind_gust_fts" => {
-        "short" => "Wgfts",
-        "unit"  => "fts",
+    wind_gust_fts => {
+        short => 'Wgfts',
+        unit  => 'fts',
     },
-    "wind_gust_kn" => {
-        "short" => "Wgkn",
-        "unit"  => "kn",
+    wind_gust_kn => {
+        short => 'Wgkn',
+        unit  => 'kn',
     },
-    "wind_gust_mph" => {
-        "short" => "Wgmph",
-        "unit"  => "mph",
+    wind_gust_mph => {
+        short => 'Wgmph',
+        unit  => 'mph',
     },
-    "wind_gust_mps" => {
-        "short" => "Wgmps",
-        "unit"  => "mps",
+    wind_gust_mps => {
+        short => 'Wgmps',
+        unit  => 'mps',
     },
-    "wind_speed" => {
-        "unified" => "wind_speed_kmh",    # link only
+    wind_speed => {
+        unified => 'wind_speed_kmh',    # link only
     },
-    "wind_speed_kmh" => {
-        "short" => "Ws",
-        "unit"  => "kmh",
+    wind_speed_kmh => {
+        short => 'Ws',
+        unit  => 'kmh',
     },
-    "wind_speed_bft" => {
-        "short" => "Wsbft",
-        "unit"  => "bft",
+    wind_speed_bft => {
+        short => 'Wsbft',
+        unit  => 'bft',
     },
-    "wind_speed_fts" => {
-        "short" => "Wsfts",
-        "unit"  => "fts",
+    wind_speed_fts => {
+        short => 'Wsfts',
+        unit  => 'fts',
     },
-    "wind_speed_kn" => {
-        "short" => "Wskn",
-        "unit"  => "kn",
+    wind_speed_kn => {
+        short => 'Wskn',
+        unit  => 'kn',
     },
-    "wind_speed_mph" => {
-        "short" => "Wsmph",
-        "unit"  => "mph",
+    wind_speed_mph => {
+        short => 'Wsmph',
+        unit  => 'mph',
     },
-    "wind_speed_mps" => {
-        "short" => "Wsmps",
-        "unit"  => "mps",
+    wind_speed_mps => {
+        short => 'Wsmps',
+        unit  => 'mps',
     },
 );
 
 # Get unit list in local language as hash
 sub GetList (@) {
     my ( $lang, $type ) = @_;
+    my $l = ( $lang ? lc($lang) : "en" );
     my %list;
 
     foreach my $u ( keys %unitsDB ) {
         my $details = GetDetails( $u, $lang );
-        my $tid     = $details->{"unit_type"};
-        my $tn      = ( $unit_types{$tid} ? $unit_types{$tid} : "unknown" );
+        my $tn = (
+              $details->{base_parameter}
+            ? $details->{base_parameter}
+            : "others"
+        );
         $list{$tn}{$u} = $details
-          if ( !$type || $type eq $tid || lc($type) eq $tn );
+          if ( !$type || lc($type) eq $tn );
     }
 
     return \%list;
@@ -1992,61 +2452,89 @@ sub GetDetails ($@) {
         foreach my $k ( keys %{ $unitsDB{$u} } ) {
             $details{$k} = $unitsDB{$u}{$k};
         }
-        $details{"unit_abbr"} = $u;
+        $details{unit_abbr} = $u;
+
+        foreach ( 'unit_ref', 'unit_ref_t', 'unit_ref_sq', 'unit_ref_cu' ) {
+            my $suffix = $_;
+            $suffix =~ s/^[a-z]+_[a-z]+//;
+            if ( defined( $details{$_} ) ) {
+                my $ref = $details{$_};
+                if ( !defined( $unitsDB{$ref} ) ) {
+                    ::Log 1, "Unit::GetDetails($unit) broken reference $_";
+                    next;
+                }
+                foreach my $k ( keys %{ $unitsDB{$ref} } ) {
+                    next if ( $k =~ /^unit_scale/ );
+                    if ( !defined( $details{$k} ) ) {
+                        $details{$k} = $unitsDB{$ref}{$k};
+                    }
+                    else {
+                        $details{ $k . $suffix } = $unitsDB{$ref}{$k}
+                          if ( !defined( $details{ $k . $suffix } ) );
+                    }
+                }
+            }
+        }
+
+        if ( $details{unit_scale_m} ) {
+            my $ref = $details{unit_scale_m};
+            foreach my $k ( keys %{ $scales_m{$ref} } ) {
+                $details{ $k . '_m' } = $scales_m{$ref}{$k}
+                  if ( !defined( $details{ $k . '_m' } ) );
+            }
+        }
+        if ( $details{unit_scale_sq} ) {
+            foreach my $k ( keys %scales_sq ) {
+                $details{ $k . "_sq" } = $scales_sq{$k}
+                  if ( !defined( $details{ $k . "_sq" } ) );
+            }
+        }
+        if ( $details{unit_scale_cu} ) {
+            foreach my $k ( keys %scales_cu ) {
+                $details{ $k . "_cu" } = $scales_cu{$k}
+                  if ( !defined( $details{ $k . "_cu" } ) );
+            }
+        }
+
+        if ( defined( $details{base_ref} ) ) {
+            my $ref = $details{base_ref};
+            foreach my $k ( keys %{ $unit_base{$ref} } ) {
+                $details{$k} = $unit_base{$ref}{$k}
+                  if ( !defined( $details{$k} ) );
+            }
+        }
 
         if ($lang) {
             $details{"lang"} = $l;
-
-            if (   $details{"txt_format"}
-                && ref( $unitsDB{$u}{"txt_format"} ) eq "HASH"
-                && $unitsDB{$u}{"txt_format"}{$l} )
-            {
-                delete $details{"txt_format"};
-                $details{"txt_format"} = $unitsDB{$u}{"txt_format"}{$l};
+            foreach ( keys %details ) {
+                if ( $details{$_}
+                    && ref( $details{$_} ) eq "HASH" )
+                {
+                    my $v;
+                    $v = $details{$_}{$l}
+                      if ( $details{$_}{$l} );
+                    delete $details{$_};
+                    $details{$_} = $v if ($v);
+                }
             }
 
-            if (   $details{"txt_format_long"}
-                && ref( $unitsDB{$u}{"txt_format_long"} ) eq "HASH"
-                && $unitsDB{$u}{"txt_format_long"}{$l} )
-            {
-                delete $details{"txt_format_long"};
-                $details{"txt_format_long"} =
-                  $unitsDB{$u}{"txt_format_long"}{$l};
-            }
+            $details{unit} = $details{scale_m} . $details{unit}
+              if ( $details{scale_m} );
+            $details{unit_long} =
+              $details{scale_long_m} . lc( $details{unit_long} )
+              if ( $details{scale_long_m} );
 
-            if (   $details{"txt_format_long_pl"}
-                && ref( $unitsDB{$u}{"txt_format_long_pl"} ) eq "HASH"
-                && $unitsDB{$u}{"txt_format_long_pl"}{$l} )
-            {
-                delete $details{"txt_format_long_pl"};
-                $details{"txt_format_long_pl"} =
-                  $unitsDB{$u}{"txt_format_long_pl"}{$l};
-            }
-
-            if (   $details{"unit"}
-                && ref( $unitsDB{$u}{"unit"} ) eq "HASH"
-                && $unitsDB{$u}{"unit"}{$l} )
-            {
-                delete $details{"unit"};
-                $details{"unit"} = $unitsDB{$u}{"unit"}{$l};
-            }
-
-            if (   $details{"unit_long"}
-                && ref( $unitsDB{$u}{"unit_long"} ) eq "HASH"
-                && $unitsDB{$u}{"unit_long"}{$l} )
-            {
-                delete $details{"unit_long"};
-                $details{"unit_long"} = $unitsDB{$u}{"unit_long"}{$l};
-            }
-
-            if (   $details{"unit_long_pl"}
-                && ref( $unitsDB{$u}{"unit_long_pl"} ) eq "HASH"
-                && $unitsDB{$u}{"unit_long_pl"}{$l} )
-            {
-                delete $details{"unit_long_pl"};
-                $details{"unit_long_pl"} = $unitsDB{$u}{"unit_long_pl"}{$l};
-            }
+            $details{unit_sq} = $details{unit_sq} . $details{scale_sq}
+              if ( $details{scale_sq} );
+            $details{unit_long_sq} =
+              $details{scale_long_sq} . lc( $details{unit_long_sq} )
+              if ( $details{scale_long_sq} );
 
+            $details{unit_cu} = $details{unit_cu} . $details{scale_cu}
+              if ( $details{scale_cu} );
+            $details{unit_long_cu} =
+              $details{scale_long_cu} . lc( $details{unit_long_cu} )
+              if ( $details{scale_long_cu} );
         }
 
         return \%details;
@@ -2106,7 +2594,7 @@ sub GetDetailsFromReadingname ($@) {
         $u = lc($1);
     }
 
-    return if ( !%return && !$u );
+    return {} if ( !%return && !$u );
     return \%return if ( !$u );
 
     my $unitDetails = GetDetails( $u, $l );