Products. Solutions. Overview colour scales

1.

Products
Solutions
Overview Colour Scales
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Slide 1
10/26/2018
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Services

2.

Overview Colour Scales
Different Colour Scales
• APHA/Hazen = PtCo
• L*a*b = CIELAB = CIEL*a*b
• ICUMSA
• Lovibond®
• EBC
• ….
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3.

Overview Colour Scales
APHA
• Synonym
• Hazen
• Pt/Co (Platinum Cobalt scale)
• Definition:
• corresponding norm: DIN EN ISO 6271:2015 Estimation of colour by the platinum cobalt
colour scale
• Colour scale corresponds to content of Platinum raning from 0 to 500 mg/l
• Procedure
• Comparison of probe against acid solution of K2PtCl6 and CoCl2
• Visual comparison or instrumental measurement
• Application
• Mainly and originally water/waster water
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4.

Overview Colour Scales
L*a*b
• Synonym
• CIELAB colour space
• CIE L*a*b
• Definition
• By International Comission on Illumination (CIE) in 1976
• Designed to be perceptually uniform to human colour vision
• Corresponding Norm:
• DIN EN ISO 11664-1: Colorimetry - Part 1: CIE standard colorimetric observers
• DIN EN ISO 11664-2: Colorimetry –Part 2: CIE standard illuminants
• DIN EN ISO 11664-3: Colorimetry –Part 3: CIE tristimulus values
• DIN EN ISO 11664-4: Colorimetry –Part 4: CIE 1976 L*a*b* Colour space
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5.

Overview Colour Scales
L*a*b
• Procedure
• Calculation from the Intensity according to DIN EN ISO 11664-1 – 11664-4
• Application
• TIFF files
• PDF “Lab colour space”
• OS X Digital Colour Meteor
• RawTherapee “Lab colour space”
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6.

Overview Colour Scales
ICUMSA
• Synonym
• ICUMSA= International Commision for Uniform Methods of Sugar Analysis
• Definition
• Photometric method to measure colour of filtrated sugar solutions
• Units: RBU /reference base units
• Range: 46 (brilliant white sugar, high quality) – 150 (dark sugar, low quality)
• Procedure
• Measures transmission at known sugar concentration (brix value) and definded wave lenghts
• λwhite sugar= 420 nm, λdark sugar= 560 nm
• Application
• Indicator for purity of sugar
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7.

Overview Colour Scales
Lovibond®
• Synonym
none
• Definition
• ISO 15305
• Procedure
• Comparison of probe with 84 glass standards of different optical density (Neutral N) and
colour (Red R, Yellow Y, Blue B)
• Colour and neutral filters are combined until colour shade and brightness are compliand
• Result: Set of RYBN glasses, which define Lovibond® colour
• Units: RYBN
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8.

Overview Colour Scales
Lovibond®
• Application
• Food & Beverage
• Oils and Fats
• Chemicals
• Pharmaceuticals
If measured photometrically, mostly two hue of red and yellow are determined
Called Lovibond® Red and Lovibond® Yellow
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9.

Overview Colour Scales
EBC
• Synonym
• European Brewery Convention
• Definition
• Determination of beer and wort colour
• Absorption of light at λ= 430 nm
• Procedure
• Filtration to turbidity smaller 1 EBC
• Determination of absorption in 10 mm cuvette
• If necessary dilution until absorption is smaller 2 extinction units (E430)
• Calculation of EBC colour scale according to E430*25*dilution factor
• Application
• Breweries
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10/26/2018
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