With the coil temperature measuring device L-Temp, the temperatures in solenoid valves can be measured during operation. The measurement is sensorless, the L-Temp uses the coil as a temperature sensor. The operating temperatures within a test item can therefore be measured without modifying it. Different winding types are easily adjustable. In the basic version, the device has either one or two measuring channels, but can be expanded to up to 12 channels using the corresponding L-Temp plug-in module from the MCM family.