Abstract: The real-time detection system with Charge-Couple Device （CCD） sensors is a kind of quality control device based on photoelectric detection technology. It was designed to visualize and measure work pieces directly on the machine tool, particularly Electric Discharge Machining (EDM). In order to improve the precision of measurements, three methods were presented to calibrate this measuring system. The methods were overall constant calibration, C calibration and D calibration. After the calibration, a series of experiments were conducted to test the stability and precision of this measuring system. Experimental results show that these methods are able to improve this real-time detection system.

Key words: CCD sensor； electric discharge machining（EDM）； precision； stability； calibration