JJF (Min) 1129-2022 is a local measurement technical specification in Fujian Province, which stipulates the calibration method of gelatin transparency tester. The specification applies to gelatin transparency tester based on the principle of Spectrophotometric method, spectra-trophotometry. The tester is mainly used in the pharmaceutical, food, chemical and other industries to detect the transmittance of 6.67% gelatin solution in gelatin products at 45 ° C at wavelengths of 450nm and 620nm. The specification specifies in detail the environmental conditions of calibrate, Measurement instruments and equipment used, calibrate items and methods, including noise, error of transmittance indication and transmittance, and sexual repeability calibrate. Calibrating results should be recorded in detail in the calibrating certificate or report to ensure the accuracy and reliability of the tester.