Analysis of the Effect of Temperature on the Accuracy of Moisture Content Measurement in Transformer Oil

Lince Markis; Paulus Susetyo Wardana; Indra Budi H

doi:10.59890/ijir.v4i6.200

Authors

Lince Markis University of 17 Agustus 1945 Surabaya, East Java, Indonesia
Paulus Susetyo Wardana Politeknik Elektronika Negeri Surabaya, East Java, Indonesia
Indra Budi H University of 17 Agustus 1945 Surabaya, East Java, Indonesia

DOI:

https://doi.org/10.59890/ijir.v4i6.200

Keywords:

Transformer Oil, Moisture Measurement, Temperature Effect, Dielectric Insulation, Karl Fischer Titration, Sensor Accuracy

Abstract

Transformer oil plays a critical role in insulation and cooling systems in power transformers. One of the key parameters affecting transformer reliability is moisture content, as excessive water contamination can reduce dielectric strength and accelerate insulation degradation. However, moisture measurement accuracy is strongly influenced by oil temperature variations during testing. This study aims to analyze the effect of temperature on the accuracy of moisture content measurements in transformer oil. The research employed an experimental approach using transformer oil samples tested at different temperature levels ranging from 20°C to 80°C. Moisture measurements were conducted using a capacitive moisture sensor and compared with Karl Fischer Titration (KFT) as the reference method. The results indicate that increasing temperature significantly affects measurement stability and accuracy. At higher temperatures, moisture readings tend to increase due to enhanced molecular activity and water solubility in oil. Statistical analysis shows that temperature contributes substantially to measurement deviation, with the highest accuracy obtained within the temperature range of 40°C–50°C. The maximum relative error reached 9.88% at 80°C, while the minimum error of 1.66% was observed at 50°C. The overall performance measured yielded an MAE of 1.29 ppm and an RMSE of 1.63 ppm. The study concludes that temperature compensation mechanisms are necessary to improve the reliability of real-time transformer oil monitoring systems

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