4
3 Functions and features
The unit continuously measures the relative water content and the temperature of
hydraulics and lubricants�
3.1 Applications
The unit is suitable for mineral oils, synthetic esters and bio oils� It covers the
following measuring ranges:
• Relative humidity: 0���100 %
• Temperature: -20���+120 °C
4 Function
4.1 Measuring principle
4.1.1 Temperature measurement
The unit measures the oil temperature by means of a platinum measuring resistor
(Pt1000).
Since the sensor is located directly in the oil, the conductivity of the
surrounding medium must not exceed a value of 3 ms/m� Too high a
conductivity deteriorates the measurement accuracy; the sensor will,
however, not be damaged�
4.1.2 Humidity measurement
The unit measures the relative water content by means of a capacitive transducer�
The oil's water saturation level is indicated in the range of 0���100 %:
0 %
dry oil
100 %
oil is fully saturated with water
(
7�1 Reference values for the assessment of the measured values
