GB/T 3048.4-2025 Test methods for electrical properties of electric cables and wires—Part 4：Test of DC resistance of conductors English, Anglais, Englisch, Inglés, えいご
1 Scope
This document specifies the test methods for the DC resistance of conductors of electric cables and wires, including test equipment, specimen preparation, test conditions, test procedures, test results and calculation, as well as test records.
This document is applicable to the measurement of the DC resistance of conductors of electric cables and wires. The measurement ranges are as follows:
——For double-arm bridges: 1×10-7Ω to 99.9Ω;
——For single-arm bridges: 1Ω and above.
This document is not applicable to the measurement of the DC resistance of conductors of electric cables and wires that have already been installed.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2900.10 Electrotechnical terminology - Electric cables
GB/T 3048.1 Test methods for electrical properties of electric cables and wires - Part 1: General
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2900.10 and GB/T 3048.1 as well as the following apply.
3.1
cables of spooled cables & cables of cables coil
samples of electric cables and wires in manufacturing length wound on cable drums or coiled into loops
4 Test equipment
4.1 The schematic diagram of a single-arm bridge is shown in Figure 1. The schematic diagram of a double-arm bridge is shown in Figure 2.
Key:
Ⓐ——Ammeter; E——DC power supply;
Ⓖ——Galvanometer; P——Shunt;
RV——Rheostat; R1, R2, R3——Bridge arm resistances;
RX——Resistance of the conductor under test; S1——Switch of DC power supply;
S2——Galvanometer switch.
Figure 1 Schematic diagram of single-arm bridge
Contents
Foreword II
Introduction V
1 Scope
2 Normative references
3 Terms and definitions
4 Test equipment
5 Specimen preparation
6 Test conditions
7 Test procedure
8 Test results and calculation
9 Test records
