1.1 requirements: the diameter of copper single wire of power extension line shall meet the process requirements

1.2 inspection method: use 0-25mm lever micrometer with scale of 0.01mm to detect the diameter of copper single wire. 2. Scratch resistance

2.1 requirements: the printed characters should be clear and solid, and the handwriting should still be clear and distinguishable after passing the scratch resistance test.

2.2 inspection method: wipe 10 times with a ball of water soaked absorbent cotton or a piece of cotton cloth, and check visually.

3.3 insulation thickness and sheath thickness

3.1 requirements: the thickness of insulation and sheath shall meet the requirements of process card.

3.2 inspection method: cut the insulation and sheath into thin slices and put them into the projector for measurement.

4 voltage test

4.1 requirements:

A. the power cord plug of SPT, SJT and SVT products shall be subjected to 1500 V and 50 Hz AC voltage test for 1 min without breakdown;

B st type 18awg-15awg product cable shall withstand 2000V 50Hz AC voltage test, 14awg-10awg product cable shall withstand 3000v50hz AC voltage test for 1min at any time, without breakdown phenomenon;

C 227iec02 (RV) cable shall withstand 2500V and 50Hz AC voltage test for 5min without breakdown;

D. wires and cables of other types of products shall be subjected to 2000V 50Hz AC voltage test for 5min without breakdown;

3.4.2 inspection method: the test shall be conducted in accordance with Article 3 of GB 5023.2 PVC insulated cables with additional voltages up to and including 450 / 750V - Part 2: Test methods.