Insulating oil testing

Insulating liquids – the lifeblood of transformers

Transformers are designed to be in operation for 40 years or even longer. For the responsible body, their positive economic balance is heavily dependent on avoiding repair times and possible downtimes.


The insulating oil is a decisive criterion for reliable operation. Its ageing condition, which is affected by oxidation, thermal stress, and contact with other materials, essentially determines the service life of the transformer. With BAUR you have an expert partner by your side, enabling you to test the insulating liquid before the transformer fails. The insulating oil testers from BAUR enable you to ensure the reliable operation of your transformers.


Test insulating oil – avoid downtimes


Insulating oil ensures the safe operation of power transformers. In addition to traditional insulating oils, new insulating liquids, such as natural or synthetic ester, are an increasingly popular choice. When insulating liquids are used for cooling and electrical insulation, impurities or ageing can have a huge impact on insulation capacity and result in plant shutdown or even an accident.


In order to prevent this, national and international standards as well as statutory provisions require the regular testing of insulating liquids. The diagnostics of the insulating liquids provides detailed information on the quality of the refining, the purity of the oil, and ageing as well as dielectric losses and dielectric strength. During the quality analysis, the results must be used to determine whether the insulating liquid still provides effective insulation or whether it needs to be reconditioned or changed.

Applications: Checking insulating liquids in transformers | BAUR GmbH

Accurate results for many decades


Even after decades of use, BAUR devices deliver precise measurement results in terms of insulating oil testing and diagnostics because they are designed for hundreds of thousands of oil sample measurements.

This has two advantages. 


  • Comparable measurement results, regardless of the device used
  • Trends can be assessed by comparing current and historic measurement results (even if the historic data was determined using a device of a previous generation)

Software solution for testing and assessment


We offer two series of devices for carrying out breakdown voltage tests and dissipation factor measurements. For both series, the BAUR ITS Lite software simplifies the processing of the measurement results, the customer-specific reporting as well as the data archiving. The BAUR ITS Lite software is used for the automatic transfer of measurement results and for the design and archiving of measurement logs from the BAUR DPA 75 C, DTA 100 C and DTL C oil testers. The logs can be stored in both PDF format and as a flexible text file (*.txt). Extensive language support and the integration of customised logos permit professional log generation.

A global leader for good reason

Applications: Over 20 standards worldwide | BAUR GmbH

Over 20 standards worldwide


BAUR works with universities, laboratories, and standardisation and test bodies to advance the testing of insulating materials and the associated standards. The expertise acquired over the last six decades in the development of our insulating oil testers has been incorporated into national and international standards, which today define the industry standard.

Applications: Report Manager | BAUR GmbH

Report Manager


BAUR Report Manager is used to automatically transfer measurement logs from BAUR oil
testers to a USB drive.

Insulating oil testing: Dissipation factor measurement and breakdown voltage

Applications: Dissipation factor measurement | BAUR GmbH
Applications: Breakdown voltage | BAUR GmbH

BAUR's solution expertise in measurement & testing technology: