Metrological Verification and Calibration of Thermogravimetric Analyzers

Thermogravimetric analyzer (TGA), one of the most important instrument for the characterization of physical and chemical properties of materials, measures the mass change of samples at a programmed temperature. The accuracy of the mass and temperature measurement of TGA is significant for the consistency of the measurement results. The weight, and the certified reference materials for melting point and Curie point were used to verify two typical TGAs according to JJG 1135-2017 Verification Regulation of Thermogravimetric Analyzers. The verification method, data analysis, result judgement and uncertainty evaluation of all metrological technique requirements including zero shift, baseline shift, indicated error and repeatability of mass, indicated error of heating rate, and indicated error and repeatability of temperature were described. Furthermore, the data analysis and uncertainty evaluation of metrological calibration were also described. The results show that by using the metrological verification and calibration, the metrological properties of TGAs were evaluated scientifically and reasonably, and the traceability of mass and temperature were achieved, which can assure the accuracy and consistency of the thermogravimetric analysis results.