calibration mixture

in analysis
https://doi.org/10.1351/goldbook.C00781
A gaseous or liquid mixture of known composition, generally comprising one or more calibration components and an @I03026@ diluent, used directly for testing and calibration of analytical instruments.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2178 [Terms] [Paper]