Development of an Online Calibration System for Digital Thermometers Based on Image Recognition
In the metrological verification of digital display thermometers,the verification of its LED indication value is one of the important verification items.A basic temperature verification system is built by using thermostatic bath,sec-ond-class standard platinum resistance thermometer,thermometer,CCD camera,strip light source and upper com-puter.According to the verification requirements of JJG 1162-2019,a digital thermometer indication verification scheme based on image processing is proposed.Through the design of online verification process,the CCD camera is used to obtain the target image and upload it to the upper computer,and automatic recognition and qualification determination of indication values are achieved by image processing algorithms.The results of indication recognition are compared with the values of the standard to achieve online calibration of digital thermometer.Through experimental verification,the recognition accuracy can reach over 96%.
digital thermometerindication verificationimage processing