Electrical characteristics of an insulating liquid may be affected deleteriously by excessive water content. A high water content may make a dielectric liquid unsuitable for some electrical applications due to deterioration of properties such as the dielectric breakdown voltage.

These tests are suitable for use in acceptance specifications, in control of processing, and in evaluating the condition of dielectric liquids in service.

1. Scope

1.1 This test method covers the measurement of water present in insulating liquids by coulometric Karl Fischer titration. This test method is used commonly for test specimens below 100 % relative saturation of water in oil. The coulometric test method is known for its high degree of sensitivity (typically 10 g H2O). This test method requires the use of equipment specifically designed for coulometric titration.

1.2 This test method recommends the use of commercially available coulometric Karl Fischer titrators and reagents.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practice and determine the applicability of regulatory limitations prior to use. For specific precautionary statements see and .

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

IEC Standard

Index Terms

coulometric Karl Fischer titration; free water; Karl Fischer method; Karl Fischer reagent; moisture content; solvent verification solutions; water content;

ICS Code

ICS Number Code 29.040.10 (Insulating oils)

Citing ASTM Standards

[Back to Top]