The PF4 differential pressure transmitter was developed in collaboration with cleanroom* experts. The thermal measurement technique allows exact measurements in the lowest measurement rang- es. Thanks to the differential pressure measurement devices, ROTRONIC customers can now mea- sure a further important parameter in addition to humidity, temperature, low dew point and CO2. Equipped with the optional temperature probe or a HygroClip2 probe, the device can be used for a wide variety of applications.