19.1 Apparent density affects the dielectric and physical characteristics of insulating board and is a factor in the economics of its use in apparatus. This test is useful for specification, design, and quality control purposes.

1.1 These test methods cover the sampling and testing of electrical insulating boards. These boards are porous, usually fibrous sheets used for dielectric and structural purposes in electrical apparatus.

1.2 These test methods are not intended for testing vulcanized fibre or molded laminated sheets.

1.3 These test methods are applicable to board materials having a nominal thickness of at least 0.030 in. (0.76 mm).

Note 1: For materials thinner than 0.030 in. (0.76 mm) see Test Methods D202.

1.4 The test methods appear in the following sections:

 
Sections

ASTM Method
Reference

Apparent Density

18 – 23

Aqueous Extract Characteristics

36 – 42

D202

Ash Content

43 – 46

T 413

Compatibility with Dielectric
 Liquids

47 – 52

D664, D877, D924,
D971, D974, D1169,
D1500, D1816,
D3455, D3487

Compressibility

79 – 85

Conditioning

11

D685

Degree of Polymerization

86 – 89

D4243

Dielectric Strength in Air

53 – 59

D149

Dielectric Strength in Oil

60 – 65

D149, D2413, D3426

Dimensions of Sheets

12 – 17

Moisture Content

31 – 35

D644

Oil Absorption

72 – 78

Reports

10

Sampling

6 – 9

D3636

Shrinkage

24 – 30

D644

Tensile Properties

66 – 71

D202

1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.6 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 consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.