Series TPEE are specially designed for the measurement of water content in oil. Series TPEE is ideal for online monitoring of moisture in lubrication or insulation oil, which is very important for the long-term performance and adaptive maintenance of plant and machinery. For instance, moisture affects dramatically the insulation characteristics of electrical transformer oil and therefore continuous monitoring is extremely important.
Humidity measurement in oil:
Similar to the humidity in the air, the water content in an oil can be described by the absolute value in ppm or by the relative value aw: - ppm (mass of water / mass of oil) - aw (actual water content as fraction of the water content in the saturated oil) aw = 0 corresponds to water-free oil, while aw = 1 describes fully saturated oil. Aw measurement with TPEE transmitter series is based on the outstanding long term stability and resistance to pollution of the TPEE capacitive sensor elements series HC.
The physical quantities measured are water activity aw and temperature T. With these quantities TPEE calculates the water content(ppm) in mineral transformer oils. Calculation of water content in non-mineral transformer oils and lubrication oils can be accomplished by downloading specific parameters of the oil.