NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Chemical Traceability What is available for industrial gases?

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Confusion - Chemistry No consistency in concepts involved with measurement traceability  confusion No consistency in concepts involved with measurement traceability  confusion Need consistent understanding of Need consistent understanding of RelationRelation RoleRole DefinitionsDefinitions UseUse Must build on the VIM 2007 definitions Must build on the VIM 2007 definitions Aka: ISO Guide 99:2007Aka: ISO Guide 99:2007

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 ISO Guide 99 Quantity Quantity Reference = measurement unit, reference material or measurement procedure or combination of theseReference = measurement unit, reference material or measurement procedure or combination of these IUPAC-IFCC format for medicine is: System- component: kind-of-quantityIUPAC-IFCC format for medicine is: System- component: kind-of-quantity Plasma (Blood)Sodium ion; amount- of-substance concentration equal to 143 mmol/l in a given person at a given time Plasma (Blood)Sodium ion; amount- of-substance concentration equal to 143 mmol/l in a given person at a given time Kind of Quantity Kind of Quantity NOTE 1 The division of the concept of ‘quantity’ according to ‘kind of quantity’ is to some extent arbitrary.NOTE 1 The division of the concept of ‘quantity’ according to ‘kind of quantity’ is to some extent arbitrary.

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 ISO Guide 99 Measurand Measurand Note - In chemistry, “analyte”, or the name of a substance or compound, are terms sometimes used for ‘measurand’. This usage is erroneous because these terms do not refer to quantities.Note - In chemistry, “analyte”, or the name of a substance or compound, are terms sometimes used for ‘measurand’. This usage is erroneous because these terms do not refer to quantities. Measurement Standard Measurement Standard realization of the definition of a given quantity, with stated quantity value and associated measurement uncertainty, used as a referencerealization of the definition of a given quantity, with stated quantity value and associated measurement uncertainty, used as a reference

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 QuantitySystem Component (Analyte) Kind of Quantity Measurement Unit ordinal Petroleum fuel Octane number NA rationalbutter Sodium chloride Amount of substance Mole per kilogram Logarithmic differential lakewaterpHone differentialthermostatwater Celsius temperature Degree Celsius draft IUPAC

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 NTRM NIST Traceable Reference Material NIST Traceable Reference Material Must include the trademark on certificateMust include the trademark on certificate Suppliers provide gas standardsSuppliers provide gas standards Special publication Special publication

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 NTRMs Mixture ComponentsAmount of Substance Range Carbon Monoxide in Nitrogen10 µmol/mol to 13 % mol/mol Carbon Monoxide in Air10 µmol/mol to 45 µmol/mol Carbon Dioxide in Nitrogen0.5 % mol/mol to 20 % mol/mol Propane in Air3 µmol/mol to 500 µmol/mol Propane in Nitrogen100 µmol/mol to 4 % mol/mol Methane in Air1 µmol/mol to 100 µmol/mol Oxygen in Nitrogen2 % mol/mol to 21 % mol/mol Nitric Oxide in Nitrogen5 µmol/mol to 3000 µmol/mol Sulfur Dioxide in Nitrogen50 µmol/mol to 3500 µmol/mol

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Principles of Traceability Methods, Measurands and Results Methods, Measurands and Results Measurement scales, Standards and Units Measurement scales, Standards and Units Calibration Calibration Effect on Measurement Results Effect on Measurement Results Controlling Fixed Conditions Controlling Fixed Conditions ECTRACE 2003

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Principles of Traceability Controlling Variables with Calibration Standards Controlling Variables with Calibration Standards Common References Allow Arbitrary Definition Common References Allow Arbitrary Definition Role of Method Development Role of Method Development Role of Method Validation Role of Method Validation Traceability and Measurement Uncertainty Traceability and Measurement Uncertainty ECTRACE 2003

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Unbroken Chain Chemistry Test Calibration LabsTesting Labs NMI Weight Thermometer Chemical standard(?) Cal Lab 1 Weight Cal Lab 3 Chemical Standard Cal Lab 2 Thermometer Chemical Standard Preparation Determinative Test Method uses Balance Thermometer Instrument Result of test unit Measurement Instrument

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Recommendations (Draft) Measurement in Chemistry Planning and Performing a measurement Planning and Performing a measurement Define the measurandDefine the measurand System, component, kind-of-quantity with any specifications System, component, kind-of-quantity with any specifications Decide the metrological reference for the final measurement resultDecide the metrological reference for the final measurement result Select the target measurement uncertaintySelect the target measurement uncertainty

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Recommendations (continued) Choose and validate a measurement procedure Choose and validate a measurement procedure Establish the calibration hierarchy to enable the creation of a metrological traceability chain for the expected measurement result Establish the calibration hierarchy to enable the creation of a metrological traceability chain for the expected measurement result Make a model uncertainty budget Make a model uncertainty budget Evaluate an approximate estimate of the expected measurement uncertainty of the measurement result based on the established calibration hierarchy Evaluate an approximate estimate of the expected measurement uncertainty of the measurement result based on the established calibration hierarchy Check whether the target measurement uncertainty will be met Check whether the target measurement uncertainty will be met

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Recommendations (continued) Acquire the relevant measuring system and calibration Acquire the relevant measuring system and calibration Carry out the measurement according to the chosen and validated measurement procedure Carry out the measurement according to the chosen and validated measurement procedure Evaluate, then calculate the actual measurement uncertainty Evaluate, then calculate the actual measurement uncertainty Report the measurement result with measured quantity values and measurement uncertainty Report the measurement result with measured quantity values and measurement uncertainty Specify the metrological traceability Specify the metrological traceability

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Implementation of Metrology in Chemistry Include basic features of metrology in chemistry in curricula of analytical chemistry Include basic features of metrology in chemistry in curricula of analytical chemistry Use concepts and associated terminology given in the VIM Use concepts and associated terminology given in the VIM Evaluate measurement uncertainty based on the GUM (e.g.; Eurachem/Citac) Evaluate measurement uncertainty based on the GUM (e.g.; Eurachem/Citac) State the metrological reference of any (chemical) measurement result State the metrological reference of any (chemical) measurement result

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 References The material was prepared from: The material was prepared from: Metrological Traceability of Measurement Results in Chemistry - Recommendations comments were due by Feb 2008Metrological Traceability of Measurement Results in Chemistry - Recommendations comments were due by Feb 2008 Analytical Chemistry Division Analytical Chemistry Division Working Party on Harmonization of quality assurance schemesWorking Party on Harmonization of quality assurance schemes Traceability in Chemical Measurements, Eurachem/CITAC Guide, 2003, in Chemical Measurements, Eurachem/CITAC Guide, 2003, ISO International Vocabulary of Basic and General Terms in Metrology (VIM): 3rd edition, 2007ISO International Vocabulary of Basic and General Terms in Metrology (VIM): 3rd edition,

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Contact information Testing Committee Chair Testing Committee Chair Marlene MooreMarlene Moore

NCSL INTERNATIONAL SERVING THE WORLD OF MEASUREMENT SINCE 1961 Questions ? Thank you Thank you