Automotive wiring harness processors should strictly inspect the quality of copper wires, and the specific inspection standards must be carried out in strict accordance with the following steps:
1. Appearance inspection: place the spool filled with copper wire on the ground packaging table, hold a piece of white paper with one hand and place it at a position 1-2cm away from the copper wire, and place the spool of copper wire with the other hand. Scroll for a week and visually check whether the appearance meets the following standards:
1) Smooth surface, no black lines, no random lines, no pitting, no oxidation, no scratches, no scratches and bumps, no poor tin plating (tin sticking, tin leakage), no slashes, no hand joints, No handprints.
3) The tension is moderate but not too loose or too tight.
4) There is no sticky ash phenomenon on the surface of the copper wire after rolling (overfilled)
2. Wire diameter inspection: The wire diameter should be strictly controlled in accordance with the national general standards, and when the customer has special requirements. The specific inspection steps are as follows:
1) First debug whether the micrometer is reset to zero.
2) Put the copper wire to be inspected outside the clamping line of the micrometer, and twist the end of the micrometer with appropriate force (the force should not be too heavy or too light).
3) Observe the reading after hearing the micrometer beep three times.
4) The readings should be repeated two or three times in this way (the same copper wire) can not detect the same position each time, and should be tested in sections.
5) For copper wires with a wire diameter of 0.2cm or more, check the different interfaces of the copper wires to avoid flat wires.
3. Elongation test: The elongation is required to be in accordance with the national standard, and the customer has special requirements to be strictly controlled according to their requirements. The specific steps are as follows:
1) Turn on the switch of the elongation tester.
2) Observe whether the clip on the left is in the original position, and whether the reading displayed by the instrument returns to zero. If the left sensing clip is not in the original position and the reading displayed by the instrument does not return to zero, press the reset button and the zero button immediately.
3) Gently open the clip, put one end of the copper wire to be tested into the induction clip, press the induction clip, then gently straighten the copper wire and put the other end into another induction clip, press the induction clip Clamp the copper wire firmly and press the test button.
4) After the induction clip breaks the copper wire and stops moving, observe the displayed reading which is the elongation rate of the detected copper wire.
4. Resistivity test: The specific test steps of resistivity requirements are as follows:
1) Turn on the power switch of the resistivity tester.
2) Clamp the sensing clips on both sides and observe whether the reading is zero.
3) If the reading displayed by the instrument is 0, take a 1m long section of the copper wire to be tested and clamp both ends of the copper wire with two induction clips. The detected copper wire should not be in contact with any metal objects, press the test key.