GB/T 30090-2013

This standard provides reference tables of temperature versus electromotive force (emf) for non-letter designated thermocouple combinations, which are specialized thermocouples not covered by standard letter-designated types (e.g., Type K, J). It is applied in metrology laboratories and industrial temperature measurement scenarios where custom or non-standard thermocouple alloys are used, ensuring accurate temperature conversion and calibration. The guide supports engineers and procurement professionals in selecting, testing, and verifying the performance of these thermocouples for precise thermal monitoring in manufacturing, research, and quality control processes.