Test gases - precision gas mixtures for the calibration of measuring equipment

Test gases are indispensable for modern measuring technology. They are used for the calibration of physical measuring processes which cannot be reduced to basic features such as mass, volume, or natural constants. With this, the measurement errors of analyzers are directly dependent on the exactness of the test gas. As an important aid in research and development, the technological sciences, the medical sciences, and in environmental protection, test gases are used if precise gas mixtures with a defined composition are required. The article focuses on the production of test gases. Furthermore, definitions are explained, test applications are described, and the analytical error prevention and aspects of test gas transfer are discussed. (orig.)