Abstract: In order to calibrate energy loss of drop hammer impact testing machines, a portable speed measuring device using a photoelectric sensor to measure the impact speed was developed. The device is mainly composed of a grooved infrared photoelectric sensor, two fixed distance cylinders, a multifunctional pulse meter and a magnetic meter base. The measurement principle: when the hammer falls at a certain speed, it drives two cylinders with a fixed distance in between to go through the sensor one after the other. A multi-functional pulse meter reads the time interval between the two cylinders covering the sensor, and then the impact speed is calculated based on the distance and time interval between the cylinders. Based on the calibration parameters, a mathematical model was established and the measurement uncertainty was evaluated. For impact speeds not greater than 10 m/s, the maximum error of measurements is within ± 0.25%. The device can be used to measure the speed of transverse impacts, inclined impacts, and vertical impacts of packaging.