Different physical processes are used to measure temperatures. Temperatures can be read off directly on a scale, e.g. by the expansion of a measuring medium.

In industry, temperatures are often measured electronically. The advantage of electronic measurement is that further processing or transmission of signals to remote locations (controllers, external displays) is easier.

The WL 920 trainer can be used to carry out and compare different temperature measurement procedures. The trainer includes liquid thermometers, bimetal thermometers, as well as a thermocouple,a Pt100 resistance thermometer and an NTC thermistor, each with different protective sleeves, for electronic temperature measurement. A psychrometer with two liquid thermometers is used to measure the relative air humidity.

To compare the different measuring methods, the temperature sensors being studied are attached to a height-adjustable device above the experimental tank. A fan ensures almost constant ambient conditions. A second tank with electronically controlled heater supplies water temperatures up to approx. 80°C.
The heated water at a specified temperature is fed into the experimental tank. By lowering the height-adjustable device, the temperature sensors are immersed in the water and the temperature measurement begins.

The measured values can be read as analogue or digital values. A 3-channel line recorder can record the measured values of the electronic temperature sensors continuously over time and thus also document the different time response. Defined temperature jumps and steady and transient temperature behaviour can be studied.