---
title: "ASTM D117"
url: "https://mat-cs.com/astm-d117/"
description: "This guide describes methods of testing and specifications for electrical insulating liquids intended for use in electrical cables, transformers, liquid-filled circuit breakers, and other electrical apparatus where the liquids are used as insulating, or heat transfer media, or both."
---

ASTM Standard

# ASTM D117

Standard Guide for Sampling, Test Methods, and Specifications for Electrical Insulating Liquids

[Back to all techniques](/analytical-techniques/)

## Abstract

This guide describes methods of testing and specifications for electrical insulating oils of petroleum origin intended for use in electrical cables, transformers, oil circuit breakers, and other electrical apparatus where the oils are used as insulating, or heat transfer media, or both. This guide is classified into the following categories: sampling practices, physical tests, electrical tests, chemical tests, and specifications. The test methods shall be as follows: aniline point; coefficient of thermal expansion; color; examination; flash and fire point; interfacial tension; pour point of petroleum products; refractive index; relative density; specific heat; thermal conductivity; turbidity; viscosity; dielectric breakdown voltage; dissipation factor and relative permittivity; gassing tendency; resistivity; stability under electrical discharge; acidity; carbon-type composition; compatibility with construction material; copper content; furanic compounds; gas analysis; gas content; inorganic chlorides and sulfates; neutralization numbers; oxidation inhibitor content; oxidation stability; polychlorinated biphenyl content; sediment and soluble sludge; sulfur; water content; mineral insulating oil for electrical apparatus; and high firepoint electrical insulating oils.

## Scope

1.1 This guide describes methods of testing and specifications for electrical insulating liquids intended for use in electrical cables, transformers, liquid-filled circuit breakers, and other electrical apparatus where the liquids are used as insulating, or heat transfer media, or both.

1.2 The purpose of this guide is to outline the applicability of the available test methods. Where more than one is available for measuring a given property, their relative advantages are described, along with an indication of laboratory convenience, precision, (95 % confidence limits), and applicability to specific types of electrical insulating liquids.

1.3 This guide is classified into the following categories: Sampling Practices, Physical Tests, Electrical Tests, Chemical Tests, and Specifications. Within each test category, the test methods are listed alphabetically by property measured. A list of standards follows:

Category

Section

ASTM Standard

_Sampling:_

3

D923

_Physical Tests:_

Aniline Point

4

D611

Coefficient of Thermal Ex-

pansion

5

D1903

Color

6

D1500

Examination: Visual Infrared

7

D1524, D2144, D2129

Flash and Fire Point

8

D92

Interfacial Tension

9

D971

Pour Point of Petroleum

Products

10

D97, D5949, D5950

Particle Count in Mineral

Insulating Oil

11

D6786

Refractive Index and Specific

Optical Dispersion

12

D1218

Relative Density (Specific

Gravity)

13

D287, D1217, D1298, D1481, D4052

Specific Heat

14

D2766

Thermal Conductivity

15

D2717

Viscosity

16

D445, D2161, D7042

_Electrical Tests:_

Dielectric Breakdown Voltage

17

D877, D1816, D3300

Dissipation Factor and Rela-

tive Permittivity (Dielectric

Constant)

18

D924

Gassing Characteristic

Under Thermal Stress

19

D7150

Gassing Tendency

20

D2300

Resistivity

21

D1169

_Chemical Tests:_

Acidity, Approximate

22

D1534

Carbon-Type Composition

23

D2140

Compatibility with Construc-

tion Material

24

D3455

Copper Content

25

D3635

Elements by Inductively

Coupled Plasma (ICP-AES)

26

D7151

Furanic Compounds in

Electrical Insulating Liquids

27

D5837

Dissolved Gas Analysis

28

D3612

Gas Content of Cable and

Capacitor Liquids

29

D831, D1827, D2945

Neutralization (Acid and

Base) Numbers

30

D664, D974

Oxidation Inhibitor Content

31

D2668, D4768

Oxidation Stability

32

D1934, D2112, D2440

Polychlorinated Biphenyl

Content (PCB)

33

D4059

Sulfur, Corrosive

34

D1275

Water Content

35

D1533

_Specification:_

Mineral Insulating Liquid for

Electrical Apparatus

36

D3487

Less Flammable Electrical

Insulating Liquids

37

D5222

Silicone Fluid used for Electrical

Insulation

38

D4652

Natural (Vegetable Oil) Ester

Fluids used in Electrical

Apparatus

39

D6871

1.4 The values stated in SI units are to be regarded as standard. The values stated in parentheses are provided for information only.