Abstract:[Summary]:Elongation tester is a reliable equipment for testing elongation characteristics of wire and metal materials. It can accurately measure the elongation (elongation) characteristics of copper wire, aluminum wire, aluminum magnesium alloy wire, wire and so on. In order to realize the field calibration of the elongation tester, an on-line calibration device for the elongation tester is developed, which can be detected on the spot without using calipers and steel tape gauges. The experimental results show that the device can meet the needs of on-line calibration of elongation tester and can be popularized greatly, and has a good application prospect.