Common test methods for insulating and sheathing materials of electric and optical cables - Part 13: Methods for general application - Measurement for determining the density - Water
1 Scope
GB/T 2951 specifies the test methods to be used for testing polymeric insulating and sheathing materials of electric cables and optical cables for power distribution and telecommunications including cables used on ships, and in offshore applications.
This part of GB/T 2951 gives the methods for determining the density, water absorption tests and shrinkage test which apply to the most common types of insulating and sheathing compounds (elastomeric, PVC, PE, PP, etc.).
1.1 Normative References
The following normative document contains provisions which, through reference in this text, constitute provisions of this part of GB/T 2951. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies.
ISO 1183:1987 Plastics — Methods for Determining the Density and Relative Density of Non-cellular Plastics
2 Test Values
Full test conditions (such as temperatures, durations, etc.) and full test requirements are not specified in this standard; it is intended that they should be specified by the standard dealing with the relevant type of cable.
Any test requirements which are given in this part may be modified by the relevant cable standard to suit the needs of a particular type of cable.
3 Applicability
Conditioning values and testing parameters are specified for the most common types of insulating and sheathing compounds and of electric and optical cables, wires and cords.
Foreword II
1 Scope
1.1 Normative References
2 Test Values
3 Applicability
4 Type Tests and Other Tests
5 Pre-conditioning
6 Test Temperature
7 Median Value
8 Methods for Determining the Density
8.1 Suspension Method (General Method)
8.2 Pycnometer Method (Reference Method)
8.3 Apparent Mass Method
8.4 Correction for Filled Polyethylene (PE)
9 Water Absorption Tests
9.1 Electrical Test
9.2 Gravimetric Water Absorption Test
10 Shrinkage Test for Insulation
10.1 Sampling
10.2 Preparation of test pieces
10.3 Procedure
10.4 Expression of results
11 Shrinkage Test for PE Sheaths
11.1 Test Equipment
11.2 Sampling
11.3 Preparation of test pieces
11.4 Test procedure
11.5 Expression of results
