The A-620 Rev A standard has passed in balloting and now is awaiting publication.   Section 19, which focuses on test requirements, was the major change to the standard.   Under "mechanical tests" it describes the expectation for assemblers following the standard to perform crimp pull testing on cables and harnesses with crimps unless one of the following exceptions apply:

1. There is an agreement by the customer of the assembly supplier not requiring testing.
2. There is an agreement by the customer of the assembly supplier to accept the testing requirements of the assembly supplier.
3. The assembly is built to class 1 or 2 requirements (General Electronics or Dedicated Service) and crimp height measurements are performed.   Crimp height measurements do not eliminate a requirement for pull tests in Class 3 (high performance products).

The PT-4000: Crimp Pull Testing Made Easy.

The PT-4000 provides pull tests on crimps in cables and harnesses for all IPC product classes.   The controlled rate of pull needed for class 2 and the 1-inch per minute rate for class 3 are strengths of the PT-4000. To see a video on the PT-4000 or to show others what crimp testing is, click on our newly updated video.

One of the problems with crimp pull tests is that they can only be used on a sample basis since they destroy the sample parts tested.   The ideal test would be non-destructive that can be done quickly and easily and applied to 100% of the parts.   Non-destructive electrical tests have not been useful.   Since the resistance of even a bad termination is much lower than a few inches of wire, the wire resistance must be eliminated requiring cutting into the wire insulation next to the crimp.

Now a promising new test technology that is non-destructive changes that, at least in battery cables and other applications with very large gauge wires.   The approach works by delivering a high current pulse through the crimp and attached wire.   Small changes in the voltage field between the termination and the adjacent wire strands are converted into a micro ohm resistance measurement providing a precise indicator of crimp quality.

To learn more about how this technology has been applied to battery cables see:

See us next at these shows:

• Assembly Tech. Expo, Rosemont, IL       Sept. 26- 28
• Aerospace Testing Expo, Anaheim, CA   November 14-16