The RAFTP/A humidity transducer registers the relative humidity 0...100% r.h. using a capacitive sensor and converts this measured value into a linear output signal 0-10 V respectively 4-20 mA. An additional passive resistive sensor is available for measuring temperature.
As an option the device has a potential-free changeover contact and a backlit display.
The display content can be rotated in 90° steps using a menu and the measured value, the switching threshold set, the state of the respective relay, the MIN/MAX measured values for the selected intervals (1 h / 6 h / 12 h / 24 h) etc. can be read out. In addition the humidity measuring device has a heating function to protect the sensor at high humidity 95...99% r.h.. If the relative humidity exceeds the threshold value set ex-works for more than 10 minutes the heating function is activated. The sensor is heated for a limited time and thus dried and protected against condensation. During the heating and the subsequent temperature balancing phase the output signal is kept stable at the last measured value before the heating function was triggered.
The humidity sensor is very well protected against contamination by a screwable sintered filter and can, if required, be finely calibrated in situ using an offset controller.