Duct Relative Humidity Transmitter 3% RH Accuracy 0-5VDC/0-10VDC & 1000pT Temp Sensor. The HU-226 is an extremely fast, stable and accurate harsh environment humidity and temperature transducer. An ePTFE (expanded Teflon) filter media protects the polymer humidity capacitance sensor. Prolonged condensing humidity, harsh environments, contaminants, fog or other extreme environmental conditions do not affect the Teflon protected cross-linked capacitive humidity sensor.