1.1 requirements: the diameter of copper single wire of UL extension wire 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 printing should be clear and firm, and the handwriting should still be clear and recognizable after 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 UL extension plug of SPT, SJT and SVT finished wires and cables shall be tested at 1500V and 50Hz for 1min without breakdown;

B st type 18awg-15awg finished cable should be tested with 2000V, 50Hz and 14awg-10awg should be tested with 3000v50hz communication voltage for 1min without breakdown;

C. 227iec02 (RV) cable shall be tested for 5 min at 2500V and 50Hz without breakdown;

D. the finished wires and cables of other models shall be tested at 2000V and 50Hz for 5min without breakdown;

3.4.2 inspection method: UL extension wire shall be inspected according to the third rule of GB 5023.2 PVC insulated cables with rated voltage up to and including 450 / 750V Part 2: Test methods.