External magnetic speed sensor for connection to UniTest 2, UniLog, and JLog2. With this sensor and two magnets, speed measurements can be made independently of light sources or artificial light influences. The magnets must be attached to the motor shaft, while the sensor itself is aligned flat to the magnets and mounted in the model at a maximum distance of 10 mm. The underside with the small black sensor faces the magnet. A built-in LED allows for easy functional control. As soon as the magnet approaches the sensor with the correct magnetic side, the LED lights up. While the connection to the UniLog is automatically recognized, the UniTest 2 requires a software switch between the internal and external sensor.