Chemical aspects of metrology in the chemical industry

 A brief description is given about the role of metrology in the chemical industry both in production and analysis. Chemical aspects in metrology such as sample stability, homogeneity, cross-contamination, cross-interference not known to other measuring fields have to be taken into account. The measurement carried out to decide about the quality of a chemical product must be fit for purpose. The measurement index (MI) can be used as a readily available key figure for this task. The quotient of the standard deviation of the measurement and the overall standard deviation of the process defines the ability of a given method to monitor process changes for a specific test item. The definition, origin and quality of reference and working calibration substances used are explained. Comparability to the first lab sample and consideration of the customer's needs are of utmost importance in the chemical industry whereas traceability to SI units is normally restricted to the calibration of laboratory equipment. Received: 25 April 2000 / Accepted: 2 August 2000