This standard specifies the test equipment, sample preparation, test steps, test results and calculations for the volume resistivity test of semi-conductive rubber and plastic materials. This standard is applicable to the measurement of the volume resistivity of rubber and plastic semi-conductive materials for wires and cables, and the measurement range is not greater than 10 to the fifth power of ohms. The test should be carried out under the conditions of an ambient temperature of 23 ± 2 degrees and a relative humidity of 50 ± 5%. GB/T 3048.3-1994 Test methods for electrical properties of wires and cables Volume resistivity test of semi-conductive rubber and plastic materials GB/T3048.3-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test methods for electrical properties of electric cables and cables
Volume resistivity test of semi-conductive rubber and plastic materials GB/T 3048.394
Replaces GB3048.383
Test methods for determining electrical properties of electric cables and wiresMeasuremeni of volumeresistivity of semi-conducting rubbers and plastics1Subject content and scope of application
This standard specifies the test equipment, sample preparation, test steps, test results and calculations for the volume resistivity test of semi-conducting rubber and plastic materials.
This standard is applicable to the measurement of volume resistivity of rubber and plastic semi-conductive materials for wires and cables, and the measurement range is not large}1. The test should be carried out under the condition of ambient temperature of 23 ± 2 (and relative humidity of (50 ± 5)%. The general requirements, definitions and periodic calibration requirements of the electrical performance test of wires and cables are specified in GB/T3048.1. 2 Reference standards
GB/T3048.1 General principles for electrical performance test methods of wires and cables 3 Test equipment
The wiring schematic diagram of the measurement system is shown in Figure 1. www.bzxz.net
1 Wiring schematic diagram of the measurement system
1 Insulation board; 2 Test piece; 3—Current 4-Potential electrode; 5-Voltmeter? 6-Ammeter 3.1 DC power supply
It can be adjusted to the power consumption between the two potential electrodes of the test piece greater than 0.1W, and its insulation resistance to ground should be not less than 10. 3.2 Electrode
3.2.1 Current electrode: A clip-shaped electrode made of brass or stainless steel, the length should not be less than the width of the test piece, and the contact width with the test piece is about Approved by the State Administration of Technical Supervision on 199405-19
Implementation on 1995-01-01
GB/T 3048.3-94
3.2.2 The potential electrode is made of stainless steel, as shown in Figure 2, the length should not be less than the width of the test piece, the distance is 15mm, and the top of the part in contact with the test piece should have a radius of not more than 0.5 mm fillet. The distance between the two measuring electrodes is 20mm, the error is not more than 10±2%, and the insulation resistance between the measuring electrodes should be greater than 100. The pressure of the potential electrode along the width of the test piece is about 65N/m3.3 The accuracy of the ammeter
is ±5%.
3.4 ​​The input impedance of the voltmeter
should not be less than 102. Electrostatic voltmeter, vacuum tube voltmeter or digital voltmeter can be used. The insulation resistance of the input end to the ground should be greater than 1020.
The width of the test piece Magic
3.5 Insulation board
Figure 2 Potential electrode
1 Insulation 12 Stainless steel electrode
The insulation resistivity should be no less than 1052·cⅡ. The sample used as current electrode F is placed on the insulation board. 3.6 Heating box
The temperature control range is required to be 70+3℃.
4 Sample preparation
4.1 At least 3 samples of the same size should be prepared for each test. The sample is a rectangular test piece with a length of 110mm. Width 50mm1, thickness 2mm or 4mm. The thickness should be measured at 6 points along the test length and the average value should be calculated. The difference between the measured value of each point and the average value should not exceed ±5%.
4.2 The surface of the test piece should be clean. If necessary, the surface of the test piece can be gently wiped with soil mixed with water, and then rinsed with steamed water, and then placed in the air (1 to dry. The surface of the test piece should not be damaged during scrubbing. It is not allowed to use organic solvents that have a corrosive or swelling effect on the test piece to clean the test piece. 4.3 Chemical or plastic molding The test piece should be placed for at least 16 hours before it can be used for testing, but the longest placement time shall not exceed 28 days. The test piece used for comparative test should have the same placement time as much as possible. 5 Test steps
5.1 Install L current electrodes at both ends of the test piece, place them on the insulating board, and heat them in a heating box at 70±3℃ for 2 hours. 5.2 After heating, take out the test piece, current electrode and insulating board as they are, and place them for 16 hours in an environment with a temperature of 23±2℃ and a relative humidity of (50±5)%.
5.3 Place the potential electrode, and the edge of the electrode in contact with the test piece should be perpendicular to the direction of current flow. The distance between the potential electrode and the current electrode at any end should be no less than 20mm.
5.4 Turn on the current. Read the current and voltage readings after charging for 1min. 5.5 The same test piece shall be measured twice. Before each measurement, the potential electrodes shall be slightly moved in parallel so that the voltage distributed on the test piece between the current electrodes can be measured as evenly as possible. The potential electrodes after the movement shall still maintain the requirements specified in Article 5.3. 6 Test results and calculations
GB/T 3048.3-94
6.1 The volume resistivity of each sample is calculated using the following formula: U·A
Where: p—volume resistivity of the sample, Q·cm; U—average value of voltage reading V;
1—average value of current reading, A;
A—cross section of the test piece, cm;
L—distance between the two potential electrodes in contact with the test piece, cm. 6.2 The volume resistivity of the semi-conductive material shall be the middle value of the calculated volume resistivities of the three samples. Additional remarks:
This standard is proposed by the Ministry of Machinery and Electronics Industry of the People's Republic of China. This standard is under the jurisdiction of the Shanghai Cable Research Institute of the Ministry of Machinery and Electronics Industry. This standard was drafted by Shanghai Cable Research Institute of the Ministry of Machinery and Electronics Industry, etc. The main drafters of this standard are Zhu Zhongzhu and Jin Biaoyi. This standard was first issued in 1983 and revised for the first time in May 1994.
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