Fundamentals of Color Measurement - ISA NorCal

1 Fundamentals of Color MeasurementISA NorCal TECH May 2 Bill DeutschlanderWorleyParsons 925-313-5628 Spectrum of Light Near InfraredUltravioletRedOrangeYellowGreenB lueIndigoVioletMicrowaveRadio WaveInfrared (IR)VisibleUltravioletX-RayGamma Ray10110101010101010101010101010-1-2-3-4 -5-6-7-8-9-10-11-12-133um2um1um 700nm400nm200nmSpectrum of Color measurement1002064007001100 Wavelength(nm)385 430 550 620 670 Yellowredblue green= Color of liquidVisible Light(VIS)Ultraviolett(UV)Near Infrared(NIR) Color Scales and Terms APHA - American Public Health Assoc.

2 , Hazen Standard astm American Society for Testing and Materials, Hazen and SayBolt Standards EBC European Brewery Convention; 430 nm, 1 cm Hazen Unit of the Color Standard Scale for APHA/ astm . Also know as Pt-Co. Saybolt Color Scale unit for Petroleum Products based upon visual comparison of Optical FiltersPhotometry - PrinciplesI0 IRAbsorption of light:Scattering of light:ISI0 IDAbsorption - Lambert Beer s Law II = I0 exp[- c d]T = I / I0A: AbsorbanceT: Transmission : Molar decading coefficientof absorption (l / mol*cm)c: Concentration of absorbing substance (mol / l)d: optical path length (OPL) (cm)I0 IdA = log T = c dAbsorption - Lambert Beer s Law IIA:AbsorbanceE: Extinction (Europe)AU: Absorbance UnitsCU.

3 Concentration Units (competitor)OD: Optical Density A = log T = c dUnits of Absorption:OD = A / OPLcmAbsorption - Lambert Beer s Law III012345 Concentration1009080706050403020100 AbsorbanceAbsorbance (A)% Transmission% TransmissionAbsorption - Lambert Beer s Law IVAbsorbance Transmission (CU) (%) 0 100 0,5 32 1 10 2 1 3 0,1 4 0,01 A = -log TAbsorption - Different Colors0,00,10,20,30,43504004505005506006 50700We lle nl nge / Wavelength (nm )S ig n a l ( C U )Gelb/YellowRot/RedBlau/BlueColor Analysis, APHA01234380430480530580 Absorbance0,00,10,20,30,40,5380430480530 580 AbsorbanceWavelength (nm)

4 500 APHA 5 cm cuvette50 APHA 5 cm cuvetteColor Analysis Single BeamAbsorption:Dual BeamAbsorption:A = c dA = Ameas - ArefArefAmeasColor Analysis - Comparison Single and Dual BeamSingle Beam Absorption: No Turbidity No Bubbles Significant Color changesDual Beam Absorption: Compensation of turbidity Compensation of bubbles High sensitivity Compensation of lamp agingArefAmeasColor IntensityColor Analysis - Typical Apps Single and Dual BeamArefAmeas Color dosage Quality control / Purity (absence of Color ) Decolorization control Color scales: APHA, Hazen, EBC, ASBC, astm , ICUMSA, Lovibond Concentration of inks / colorants Residual Color in waste water Metals in solution: Iron, copper, nickel, chromium Huminic matter in drinking water Chlorophyll in edible oil Bleaching of edible oil, sugar Lignin in hydrosulforic acid Dissolved water in organics Phase separation: organic and aqueous phase Chlorine / chlorine dioxide / hypochlorite Phase separation.

5 - Beer / Water- Wine / Water- Juice / Water- Hemoglobinconcentration in bloodColor Analyzer Manufacturers Ametek Process Instruments Model 4000 Galvanic Applied Sciences Monitek Monispec AD Optek Model AF26 Sigrist ColorPlus Wedgewood Analytical Model AF21, AF22 Ametek Model 4000 GAS Monitek Monispec ADOptek Control 4000/AF26 Sigrist ColorPlusWedgewood Analytical 980/AF21,AF22