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copper relative atomic mass
copper relative atomic mass, Total:132 items.
In the international standard classification, copper relative atomic mass involves: Non-ferrous metals, Quantities and units, Water quality, Crude petroleum, Metalliferous minerals, Products of the chemical industry, Soil quality. Pedology, Testing of metals, Petroleum products in general, Fuels, Animal feeding stuffs, Powder metallurgy, Beverages, Photography, Organic chemicals, Farming and forestry, General methods of tests and analysis for food products, Meat, meat products and other animal produce, Materials and articles in contact with foodstuffs, Analytical chemistry, Products of non-ferrous metals, Pharmaceutics, Paint ingredients.
RU-GOST R, copper relative atomic mass
- GOST R 57060-2016 Copper. Measurement of impurities mass fraction in copper by an inductively coupled plasma atomic emission spectrometry method
- GOST 34247-2017 Copper concentrate. Measurement of copper and impurities weight fraction by an inductively coupled plasma atomic emission spectrometry method
- GOST 34248-2017 Copper and polymetallic ores. Measurement of copper and impurities weight fraction by an inductively coupled plasma atomic emission spectrometry method
- GOST R 55761-2013 Batches, sugar mash, brew from food raw material. Determination mass concentration of cations, anions of non-organic and organic acids content by capillary electrophoresis method
- GOST R 50061-1992 Surface active agents. Sulfated ethoxylated alcohols and alkylphenols. Estimation of the mean relative molecular mass
- GOST R 56372-2015 Mixed feed, concentrates and premixes. Determination of mass fraction of iron, manganese, zinc, cobalt, copper, molybdenum and selenium by atomic absorption spectroscopy method
- GOST 32881-2014 Food products, food raw materials. Method for determination of the non-steroidal anti-inflammatory drug residue content by high performance liquid chromatography - mass spectrometry
- GOST 33616-2015 Food products, food raw materials. Method for determination of residues of arsenic containing growth stimulators using high performance liquid chromatography-mass spectrometry with inductively coupled plasma
- GOST R ISO 16962-2012 Zinc and/or aluminium based coatings on steel. Determination of coating thickness, chemical composition and mass per unit area byglow discharge atomic emission spectrometry method
CZ-CSN, copper relative atomic mass
- CSN 65 2475-1981 Sodium Chloride (Salt) Method of Atomie Absorption Spectroscophy of Copper Content Determination
General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China, copper relative atomic mass
- GB/T 5113-1985 Atomic mass unit and kilogram conversion tables
- GB/T 17282-1998 Method for estimation of molecular weight (relative molecular mass) of petroleum oils from viscosity measurements
- GB/T 17138-1997 Soil quality--Determination of copper, zinc--Flame atomic absorption spectrophotometry
- GB/T 17282-2012 Test method for estimation of mean relative molecular mass of petroleum oils from viscosity measurements
- GB/T 42511-2023 Determination of calcium, copper, iron, potassium, magnesium, manganese, sodium, nickel and zinc in cemented carbide cobalt powder by flame atomic absorption spectrometry
- GB/T 11988-2008 Surface active agents-Technical alkane sulfonates-Determination of mean relative molecular mass and content of the alkane monosulfonate
- GB/T 7717.16-2022 Acrylonitrile for industrial use—Part 16: Determination of iron and copper content—Graphite furnace atomic absorption spectrometry and inductively coupled plasma mass spectrometry
- GB/T 5178-2008 Surface active agentsm-Determination of mean relative molecular mass for technical straight-chain sodium alkylbenzenesulfonates--
Gas-liquid chromatographic method
Indonesia Standards, copper relative atomic mass
- SNI 06-2515-1991 Water, Test method for copper content by atomic absorption spectrophotometer in an extraction manuver
- SNI 06-2516-1991 Water, Test method for copper content by carbon stove atomic absorption spectrophotometer apparatus
British Standards Institution (BSI), copper relative atomic mass
- BS DD CEN/TS 15022-4:2006 Copper and copper alloys - Determination of tin content - Medium tin content - Flame atomic absorption spectrometry method (FAAS)
- BS DD CEN/TS 15022-4:2007 Copper and copper alloys. Determination of tin content. Medium tin content. Flame atomic absorption spectrometry method (FAAS)
- BS EN 15022-4:2011 Copper and copper alloys. Determination of tin content. Medium tin content. Flame atomic absorption spectrometric method (FAAS)
- BS 6829-3.1:1989 Analysis of surface active agents (raw materials). Sodium alkylbenzenesulphonates. Method for determination of mean relative molecular mass
- BS EN 15916-2:2010 Copper and copper alloys.
Determination of tellurium
content.
Part 2: Medium tellurium content.Flame
atomic absorption spectrometric method
(FAAS)
- BS 6829-5.2:1989 Analysis of surface active agents (raw materials). Ethoxylated alcohol and alkylphenol sulphates. Method for estimation of mean relative molecular mass
- 20/30404078 DC BS EN 16274. Method for Analysis of Allergens. Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry
- BS EN ISO 6845:1989 Surface active agents - Technical alkane sulfonates - Determination of mean relative molecular mass and content of the alkane monosulphonates and the alkane monosulfonate content
- BS EN ISO 6845:2003 Surface active agents. Technical alkane sulfonates. Determination of mean relative molecular mass and content of the alkane monosulphonates and the alkane monosulfonate content
- BS 6068-2.29:1987 Water quality - Physical, chemical and biochemical methods - Determination of cobalt, nickel, copper, zinc, cadmium and lead: flame atomic absorption spectrometric methods
- BS 7755-3.13:1998 Soil quality. Chemical methods. Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil. Flame and electrothermal atomic absorption spectrometric methods
- 23/30461294 DC BS ISO 18118. Surface chemical analysis. Auger electron spectroscopy and X-ray photoelectron spectroscopy. Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
- BS ISO 18118:2015 Tracked Changes. Surface chemical analysis. Auger electron spectroscopy and X-ray photoelectron spectroscopy. Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
- BS ISO 18118:2005 Surface chemical analysis - Auger electron spectroscopy and X-ray photoelectron spectroscopy - Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
American Society for Testing and Materials (ASTM), copper relative atomic mass
- ASTM D2502-04(2009) Standard Test Method for Estimation of Molecular Weight (Relative Molecular Mass) of Petroleum Oils From Viscosity Measurements
- ASTM D2502-92(1996) Standard Test Method for Estimation of Molecular Weight (Relative Molecular Mass) of Petroleum Oils From Viscosity Measurements
- ASTM D2502-12 adjunct(2020) Standard Test Method for Estimation of Molecular Weight (Relative Molecular Mass) of Petroleum Oils From Viscosity Measurements
- ASTM D2502-92(2002) Standard Test Method for Estimation of Molecular Weight (Relative Molecular Mass) of Petroleum Oils From Viscosity Measurements
- ASTM D2503-92(2002)e1 Standard Test Method for Relative Molecular Mass (Molecular Weight) of Hydrocarbons by Thermoelectric Measurement of Vapor Pressure
- ASTM D2503-92(2007) Standard Test Method for Relative Molecular Mass (Molecular Weight) of Hydrocarbons by Thermoelectric Measurement of Vapor Pressure
- ASTM D2503-92(2012) Standard Test Method for Relative Molecular Mass (Molecular Weight) of Hydrocarbons by Thermoelectric Measurement of Vapor Pressure
- ASTM D2502-14(2019) Standard Test Method for Estimation of Mean Relative Molecular Mass of Petroleum Oils from Viscosity Measurements
- ASTM D2502-14(2019)e1 Standard Test Method for Estimation of Mean Relative Molecular Mass of Petroleum Oils from Viscosity Measurements
- ASTM D2502-14 Standard Test Method for Estimation of Mean Relative Molecular Mass of Petroleum Oils from Viscosity Measurements
- ASTM D2503-82(1987)e1 Standard Test Method for Molecular Weight (Relative Molecular Mass) of Hydrocarbons by Thermoelectric Measurement of Vapor Pressure
- ASTM E841-12 Standard Test Method for Determination of Copper in Iron Ores and Related Materials by Atomic Absorption Spectrometry
- ASTM D2503-92(1997) Standard Test Method for Relative Molecular Mass (Molecular Weight) of Hydrocarbons by Thermoelectric Measurement of Vapor Pressure
- ASTM D2503-92(2016) Standard Test Method for Relative Molecular Mass (Molecular Weight) of Hydrocarbons by Thermoelectric Measurement of Vapor Pressure
- ASTM E841-04 Standard Test Method for Determination of Copper in Iron Ores and Related Materials by Atomic Absorption Spectroscopy
- ASTM E841-99 Standard Test Method for Determination of Copper in Iron Ores and Related Materials by Atomic Absorption Spectroscopy
- ASTM E841-12a Standard Test Method for Determination of Copper in Iron Ores and Related Materials by Flame Atomic Absorption Spectrometry
- ASTM E1735-95(2000)e1 Standard Test Method for Determining Relative Image Quality of Industrial Radiographic Film Exposed to X-Radiation from 4 to 25 MV
- ASTM E1735-19 Standard Practice for Determining Relative Image Quality Response of Industrial Radiographic Imaging Systems from 4 to 25 MeV
VN-TCVN, copper relative atomic mass
- TCVN 6193-1996 Water quality.Determination of cobalt nickel, copper, zinc, cadmium, and lead.Flame atomic absorption spectrometric methods
Association Francaise de Normalisation, copper relative atomic mass
- XP ISO/TS 10832:2010 Qualité du sol - Effets des polluants vis-à-vis des champignons mycorhyzogènes - Essai de germination des spores
- NF ISO 6841:1988 Agents de surface - Alkylbenzène sulfonates de sodium linéaires techniques - Détermination de la masse moléculaire relative moyenne par chromatographie gaz-liquide.
- NF ISO 6843:1988 Agents de surface - Sulfates d'alcools et d'alkylphenols éthoxylés - Évaluation de la masse moléculaire relative moyenne.
- NF EN ISO 6845:2003 Agents de surface - Alcanesulfonates techniques - Détermination de la masse moléculaire relative moyenne des alcanemonosulfonates et de leur teneur
- NF T75-616*NF EN 16274:2021 Method for analysis of allergens - Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry
- NF T73-238*NF EN ISO 6845:2003 Surface active agents - Technical alkane sulfonates - Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content
Professional Standard - Light Industry, copper relative atomic mass
- QB/T 2345-2013 Determination of mean relative molecular weight of alkyldimethylbetain by GC
- QB/T 2345-1997 Determination of the Average Relative Molecular Mass of Fatty Alkyl Dimethyl Betaines by Gas-Liquid Chromatography
- QB/T 1914-2013 Determination of mean relative molecular weight of alkyltrimethylammonium halide and alkyldimethylbenzylammonium halide by GC
BE-NBN, copper relative atomic mass
- NBN T 94-404-1977 Determination of the copper mass in particles collected by air filtration - Atomic absorption spectrophotometry
- NBN T 63-162-1988 Surface active agents - Sulfated ethoxylated alcohols and alkylphenols - Estimation of the mean relative molecular mass
ES-AENOR, copper relative atomic mass
Professional Standard - Commodity Inspection, copper relative atomic mass
- SN/T 2047-2008 Determination of impurities in copper concentrates for import.Inductively coupled plasma atomic emission spectrometry
- SN/T 1797.10-2008 Technical regulation on safety and sanitation for insepcetion of iron ore.Part 10:Relative reducibility for quality evaluation
Group Standards of the People's Republic of China, copper relative atomic mass
- T/ZJBX 10-2021 Determination of the proportion of protein hydrolysates with relative molecular weight less than 1000u in protein feed
- T/CGA 031-2022 Method for chenical analysis of water in gold industry—Determination of silver, arsenic, barium, cadmium, chromium, copper, iron, manganese, nickel, lead and zinc content—Inductively coupled plasma optical emission spectrometry
Korean Agency for Technology and Standards (KATS), copper relative atomic mass
- KS M ISO 6841-2007(2018) Surface active agents－Technical straight-chain sodium alkylbenzenesulfonates－Determination of mean relative molecular mass by gas-liquid chromatography
- KS I ISO 11047:2019 Soil quality — Determination of cadmium, chromium, cobalt, copper,lead, manganese, nickel and zinc in aqua regia extracts of soil —Flame and electrothermal atomic absorption spectrometric methods
- KS I ISO 11047:2009 Soil quality-Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil-Flame and electrothermal atomic absorption spectrometric methods
- KS M ISO 6845-2007(2018) Surface active agents－Technical alkane sulfonates－Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content
- KS D ISO 18118:2005 Surface chemical analysis－Auger electron spectroscopy and X-ray photoelectron spectroscopy－Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
International Organization for Standardization (ISO), copper relative atomic mass
- ISO 6841:1983 Surface active agents — Technical straight-chain sodium alkylbenzenesulphonates — Determination of mean relative molecular mass — Gas-liquid chromatographic method
- ISO 6843:1988 Surface active agents; sulfated ethoxylated alcohols and alkylphenols; estimation of the mean relative molecular mass
- ISO 6845:1982 Surface active agents — Technical alkane sulphonates — Determination of mean relative molecular mass of alkane monosulphonates
- ISO 6841:1988 Surface active agents; technical straight-chain sodium alkylbenzenesulfonates; determination of mean relative molecular mass by gas-liquid chromatography
- ISO 13876:2013 Soil quality.Determination of polychlorinated biphenyls (PCB) by gas chromatography with mass selective detection (GC-MS) and gas chromatography with electron-capture detection (GC-ECD)
- ISO 11047:1998 Soil quality - Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil - Flame and electrothermal atomic absorption spectrometric methods
- ISO 6845:1989 Surface active agents; technical alkane sulfonates; determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content
- ISO 18118:2004 Surface chemical analysis - Auger electron spectroscopy and X-ray photoelectron spectroscopy - Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
- ISO 18118:2015 Surface chemical analysis - Auger electron spectroscopy and X-ray photoelectron spectroscopy - Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
- ISO/DIS 18118:2023 Surface chemical analysis — Auger electron spectroscopy and X-ray photoelectron spectroscopy — Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
- ISO/FDIS 18118:2023 Surface chemical analysis — Auger electron spectroscopy and X-ray photoelectron spectroscopy — Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
KR-KS, copper relative atomic mass
- KS M ISO 6843-2008 Surface active agents－Sulfated ethoxylated alcohols and alkylphenols－Estimation of the mean relative molecular mass
- KS I ISO 11047-2019 Soil quality — Determination of cadmium, chromium, cobalt, copper,lead, manganese, nickel and zinc in aqua regia extracts of soil —Flame and electrothermal atomic absorption spectrometric methods
- KS M ISO 6841-2007(2023) Surface active agents－Technical straight-chain sodium alkylbenzenesulfonates－Determination of mean relative molecular mass by gas-liquid chromatography
- KS M ISO 6845-2007(2023) Surface active agents－Technical alkane sulfonates－Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content
API - American Petroleum Institute, copper relative atomic mass
- API MPMS 11.1 VOL IV-1980 Manual of Petroleum Measurement Standards Chapter 11.1 - Volume Correction Factors Volume IV Table 23A - Generalized Crude Oils Correction of Observed Relative Density to Relative Density 60/60 Degrees F Table 24A - Generalized Crude Oils Correction of Vo
German Institute for Standardization, copper relative atomic mass
- DIN EN 16274:2021-11 Method for analysis of allergens - Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry; German version EN 16274:2021
- DIN EN 16274:2021 Method for analysis of allergens - Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry; German version EN 16274:2021
- DIN ISO 11047:2003 Soil quality - Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil - Flame and electrothermal atomic absorption spectrometric methods (ISO 11047:1998)
- DIN EN ISO 6845:2003 Surface active agents - Technical alkane sulfonates - Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content (ISO 6845:1989); German version EN ISO 6845:2003
- DIN ISO 11047:2003-05 Soil quality - Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil - Flame and electrothermal atomic absorption spectrometric methods (ISO 11047:1998)
- DIN EN ISO 6845:2003-06 Surface active agents - Technical alkane sulfonates - Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content (ISO 6845:1989); German version EN ISO 6845:2003
- DIN EN 13615:2002 Methods for the analysis of ingot tin - Determination of impurity element contents in tin grades 99,90 % and 99,85 % by atomic spectrometry; German version EN 13615:2001
- DIN ISO 7627-6:1991-07 Hardmetals; chemical analysis by flame atomic absorption spectrometry; determination of chronium in contents from 0,01 to 2 % (m/m); identical with ISO 7627-6:1985
- DIN ISO 7627-3:1991-07 Hardmetals; chemical analysis by flame atomic absorption spectrometry; determination of cobalt, iron, manganese and nickel in contents from 0,01 to 0,5 % (m/m); identical with ISO 7627-3:1983
- DIN ISO 7627-4:1991-07 Hardmetals; chemical analysis by flame atomic absorption spectrometry; determination of molybdenum, titanium and vanadium in contents from 0,01 to 0,5 % (m/m); identical with ISO 7627-4:1983
- DIN ISO 7627-2:1991-07 Hardmetals; chemical analysis by flame atomic absorption spectrometry; determination of calcium, potassium, magnesium and sodium in contents from 0,001 to 0,02 % (m/m); identical with ISO 7627-2:1983
AENOR, copper relative atomic mass
- UNE 55842:1990 SURFACE ACTIVE AGENTS. SULFATED ETHOXYLATED ALCOHOLS AND ALKYLPHENOLS. ESTIMATION OF THE MEAN RELATIVE MOLECULAR MASS
- UNE 55806:1990 SURFACE ACTIVE AGENTS. TECHNICAL STRAIGHT-CHAIN SODIUM ALKYLBENZENESULFONATES. DETERMINATION OF MEAN RELATIVE MOLECULAR MASS BY GAS-LIQUID CHROMATOGRAPHY
- UNE 77309:2001 Soil quality. Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil. Flame and electrothermal atomic absorption spectrometric methods.
- UNE-EN ISO 6845:2003 Surface active agents - Technical alkane sulfonates - Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content (ISO 6845:1989)
Professional Standard - Geology, copper relative atomic mass
- DZ/T 0064.83-2021 Methods of analysis of groundwater quality - Part 83: Determination of copper, zinc, cadmium, nickel and cobalt by flame atomic absorption spectrophotometry
- DZ/T 0064.21-2021 Methods of analysis of groundwater quality - Part 21: Determination of copper, lead, zinc, cadmium, nickel, chromium, molybdenum and silver by flameless atomic absorption spectrophotometry
- DZ/T 0064.20-2021 Analytical methods of groundwater quality - Part 20: Determination of copper, lead, zinc, cadmium, nickel and cobalt content Chelating resin exchange enrichment flame atomic absorption spectrophotometry
ESDU - Engineering Sciences Data Unit, copper relative atomic mass
- SPB-M6-2-2010 Apr.08: Colloidal Interactions Between Asphaltene and Different Surfaces Measured by Atomic force microscopy (AFM)
AT-ON, copper relative atomic mass
- OENORM EN 16274-2021 Method for analysis of allergens - Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry
CH-SNV, copper relative atomic mass
- SN EN 16274-2021 Method for analysis of allergens - Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry
IT-UNI, copper relative atomic mass
- UNI EN 16274-2021 Method for analysis of allergens - Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry
Lithuanian Standards Office , copper relative atomic mass
- LST EN 16274-2021 Method for analysis of allergens - Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry
- LST ISO 11047:2004 Soil quality. Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil. Flame and electrothermal atomic absorption spectrometric methods (idt ISO 11047:1998)
- LST EN ISO 6845:2003 Surface active agents - Technical alkane sulfonates - Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content (ISO 6845:1989)
ES-UNE, copper relative atomic mass
- UNE-EN 16274:2022 Method for Analysis of Allergens - Quantification of an extended list of 57 suspected allergens in ready to inject fragrance materials by gas chromatography mass spectrometry
海关总署, copper relative atomic mass
- SN/T 5323-2021 Determination of the migration amount of parabens in food contact materials, polymer materials, plastics, liquid chromatography-tandem mass spectrometry
European Committee for Standardization (CEN), copper relative atomic mass
- EN ISO 6845:2003 Surface active agents - Technical alkane sulfonates - Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content
IN-BIS, copper relative atomic mass
Danish Standards Foundation, copper relative atomic mass
- DS/EN ISO 6845:2003 Surface active agents - Technical alkane sulfonates - Determination of the mean relative molecular mass of the alkane monosulfonates and the alkane monosulfonate content
- DS 263:1982 Water quality. Determination of metal in water, sludge and sediment by atomic absorption spectrophotometry in flam. Special guidelines for cadmium, cobalt copper, iron nickel, lead and zink
Japanese Industrial Standards Committee (JISC), copper relative atomic mass
- JIS K 0167:2011 Surface chemical analysis -- Auger electron spectroscopy and X-ray photoelectron spectroscopy -- Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
GOSTR, copper relative atomic mass
- GOST 34596-2019 Food products, feed, food raw materials. Determination of the mass fraction of methylmercury compounds and inorganic mercury compounds by high performance liquid chromatography-mass spectrometry with inductively coupled plasma
Standard Association of Australia （SAA）, copper relative atomic mass
- AS ISO 18118:2006 Surface chemical analysis - Auger electron spectroscopy and X-ray photoelectron spectroscopy - Guide to the use of experimentally determined relative sensitivity factors for the quantitative analysis of homogeneous materials
Hebei Provincial Standard of the People's Republic of China, copper relative atomic mass
- DB13/T 5127.8-2019 Determination of Toxic and Hazardous Substances in Extracts of Implantable Medical Device Polymer Materials by High Performance Liquid Chromatography for Migration of Terephthalic Acid
TH-TISI, copper relative atomic mass
- TIS 1780.16-1999 General Methods of test for pigments and extenders part 16:determination of relative tinting strength (or equivalent colouring value)and colour on reduction of coloured pigments-visual comparison method