What is the response time of the moisture in oil sensor?

The thin-film polymer capacitive sensor is extremely responsive to a small step change in moisture level. This can be demonstrated by grasping the probe in your hand. The moisture from your skin will be detected within 2-3 seconds. However, this response time is diminished in oil due to the oil’s viscosity and the slow rate of travel of water through the oil. In still oil at 20 °C, 90% of the reading will be reached in ten minutes.  This response time dramatically improves by installing the probe in a flowing oil line. Since the sensor detects water by absorption, the greater the flow rate, the faster the response time.