ASTM D3612

ASTM D3612 – Standard Test Method for Analysis of Gases Dissolved in Electrical Insulating Oil by Gas Chromatography

Description:

Significance and Use

5.1 Oil and oil-immersed electrical insulation materials may decompose under the influence of thermal and electrical stresses, and in doing so, generate gaseous decomposition products of varying composition which dissolve in the oil. The nature and amount of the individual component gases that may be recovered and analyzed may be indicative of the type and degree of the abnormality responsible for the gas generation. The rate of gas generation and changes in concentration of specific gases over time are also used to evaluate the condition of the electric apparatus.

Note 1: Guidelines for the interpretation of gas-in-oil data are given in IEEE C57.104.

Scope

1.1 This test method covers three procedures for extraction and measurement of gases dissolved in electrical insulating oil having a viscosity of 20 cSt (100 SUS) or less at 40°C (104°F), and the identification and determination of the individual component gases extracted. Other methods have been used to perform this analysis.

1.2 The individual component gases that may be identified and determined include:

	Hydrogen—H2
	Oxygen—O2
	Nitrogen—N2
	Carbon monoxide—CO
	Carbon dioxide—CO2
	Methane—CH4
	Ethane—C2H6
	Ethylene—C2H4
	Acetylene—C2H2
	Propane—C3H8
	Propylene—C3H6