Automatic timing device for constant load tensile testing equipment

The invention relates to an automatic timing device, in particular to an automatic timing device for constant load tensile testing equipment. The automatic timing device comprises a timing and display part, a photoelectric switch part and a switch locator, and specifically comprises a 8-digit timer, a photoelectric switch and a magnetic gauge stand, wherein the photoelectric switch is used for detecting lever arm state change after fracture of a test specimen. According to the automatic timing device, the photoelectric switch is fixed on the constant load tensile testing equipment by the photoelectric switch, and is triggered by the lever arm position change during fracture of the test specimen to send a signal, and the signal stops timing of the timer and displays a count on a timer screen. Compared with the fact that the conventional constant load tensile testing equipment requires an experimenter to wait beside the equipment for manual timing, the automatic timing device for the constant load tensile testi