Abstract

It is very challenging to measure moisture levels in oils. There is not a good method to measure it. Using the novel moisture sensor invented by Dr. Zhi David Chen, we tried various methods to measure the moisture levels in oils. The initial trials are to immerse the sensor chip into the oils to see any sensor reading changes with the change of moisture levels in oils. It was observed that the sensor reading was unstable even after immersion into the oil for two weeks. The idea for immersion of the sensor chip into the oils failed due to the instability of the sensor.

It is known our sensor is very stable in air or nitrogen. The second idea was to heat the oil so that the moisture inside the oil evaporated to the atmosphere in enclosed space above the oil. Because the humidity in air was very high and the moisture level in oil was very low, it is necessary to purge the enclosed space to a very dry condition by a dry nitrogen flow for overnight. After this, the oil was heated and it was observed that dew point (moisture) increased with time. It is difficult to correlate the dew point or PPMv reading to the moisture inside the oil.

The last idea is to heat the oil to let all moisture evaporated fully. Before heating, the dew point (PPMv) can be measured. During heating the dew point (PPMv) increased to the maximum and began to decrease until the dew point (PPMv) became the same as dew point (PPMv) before heating. This means that all moisture inside the oil was fully evaporated. By integration of the dew point (PPMv) with time or the area inside the curve (S), one can link S with moisture levels using an empirical parameter A. Once A is determined, one can obtain S in any oils to calculate the moisture levels in the Oil.

Document Type

Article

Publication Date

Spring 6-11-2025

Notes/Citation Information

[1] Dr. JiangBiao He, Dr. Chen, Reza Ilka, Yiju Wang. Power Electronic Converters with Advanced Immersion Cooling and Moisture Sensor Technologies, Monthly Progress Report, 2024.

[2] Zhi David Chen. Novel Humidity Sensors Based on Nanoscale Hybrid Dielectric Materials, the Electrochemical Society Interface, Winter 2017.

[3] Zhi Chen. Dew Point Sensors and Their Manufacturing Method, Chinese Patent No. 201410246545 (2016).

[4] Zhi Chen. Hybrid Dielectric Moisture Sensors, US Patent No. 9,285,334 (2016).

[5] Zhi David Chen. Novel Humidity Sensors Based on Nanoscale Hybrid Dielectric Materials, the Electrochemical Society Interface, Winter 2017.

[6] Zhi Chen, Mao-Chang Jin, Chao Zhen, and Guan-Hua Chen. Properties of Modified Anodic-Spark-Deposition Alumina Porous Ceramic Films as Humidity Sensors, Department of Materials Science and Engineering, 1991.

[7] Zhi Chen and Mao-Chang Jin. An Alpha- Alumina Moisture Sensor for Relative and Absolute Humidity Measurement, Department of Materials Science and Engineering, 2019.

[8] Valvoline. Standard Test Method for Determination of Water Petroleum Products, Lubricating Oils, and Additives by Coulometric Karl Fischer Titration, ASTM Int’l 2020.

[9] Valvoline et al. Additive in Oils, (n.d.).

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