Water in Oil Sensor
The sensor is suitable for the detection of water penetration in a hydraulic oil or lubricating oil circuit.
Working principle of the sensor is a capacitive measurement of the water content in the oil. The physically measured value is called “water activity” (aw = water activity). New oil has the characteristic to bind a certain amount of the dissolving water. The maximum water concentration in the oil is the so-called “saturation point”. If this saturation point is exceeded, the surplus water can lead to corrosion in machines. The saturation point of the oil depends on the temperature and other various factors, such as on its composition, whether mineral or synthetic, the addition of additives and also changes with the aging of the oil.
The sensor measures the content of dissolved water in oil and triggers an alarm as soon as the water content, which had been set before as PAV (Pre Alarm Value 0.5aw) or MAV (Main AlarmValue 0.9aw), is exceeded.
Sensors with 4 – 20 mA output for the AW-value and the temperature are available.