The Development of the Calibration System for the Clock Tester

This article uses NI-VISA technology combined with image recognition technology of OPENCV and Tesseract to develop a set of automatic calibration system for clock testers. This system uses PC to control general-purpose counter, function signal generator, RF switch and camera through USB interface, GPIB interface and RS232 interface. It has realized effective traceability of daily clock time difference rate, frequency, warm-up characteristics, frequency offset and time offset parameters of clock testers according to JJF1662-2017. Currently, this system has been in use for one year, which effectively solves the problems of low efficiency and high error rate in traditional manual calibration. This article first analyzes and compares similar systems, then elaborates the hardware structure and the implementation method of key technologies of this system. It then shows the data and curves tested by this system, and finally summarizes the advantages of this system.