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Temperature Calibration in Transformer Stations

temperature calibration for transformer sensors

Ensure Higher Throughput and Safety at Transformer Stations
Transformer stations convert high voltages from power plant lines to lower voltages that can be used in local households.

The process of converting one voltage to another causes energy loss, which in turn is converted into heat. This elevated temperature heats up the oil in which the transformer coils are placed. As the transformer heats up, the throughput efficiency is reduced due to higher resistance in the coils, causing even more heat dissipation.

There is a serious risk associated with this process. If it is allowed to heat up too fast, the oil cooling system may not cool sufficiently, possibly causing a transformer to burn-out.

To better control the temperature and help prevent these dangerous conditions, special sensors are used to monitor the temperature in the oil.

What makes these sensors special, is that they perform multiple measurements. This redundancy is used to monitor and control the oil-cooling system, and if necessary, to shut down the transformer altogether.

The system employs long, capillary sensors with a very long thermosensitive element, and need to be calibrated to ensure perfect control of the transformer station.

Due to the length of the sensor, the calibration requires a temperature calibrator with a very deep immersion depth; and one that can perform very accurate calibration.

The JOFRA CTC-652 temperature calibrator features an immersion depth of 190 mm and is specially developed to serve this purpose.

Using the CTC-652 temperature calibrator with a reference sensor, an accuracy of 0.35°C / 0.63°F at a calibration temperature of 200°C / 392°F can be obtained.

The key to an accurate calibration of very long sensors is that the active part of the sensor be fully immersed. The CTC-652 temperature calibrator serves this purpose; and is light weight and easy to carry, heats very quickly, and needs only 5 minutes to stabilize.

Click here for a pdf version of the application note.