The instrument is powered by 24Vdc. The DewTrak II uses the chilled mirror dew point temperature condensation principle to determine the water vapor concentration in gas mixtures, and a platinum resistance thermometer to accurately measure that temperature. Outputs include 4 to 20mA, 0 to 5 Vdc, or 0-10Vdc and an RS232 serial port as well as electrically isolated relay contacts.