The application of wire injection to harnesses

The testing of harness assemblies for screening performance is an issue for any company in the business of manufacturing them. The paper looks at adopting the new IEC 96.4.1 wire injection technique for the purpose of evaluating simple harness assemblies. It compares the screening performance of a harness using the wire injection technique to other test methods, such as the VG and ground plane techniques. It addresses the methods of sample construction, matching, termination and describes the use of the technique in the manufacturing environment where quality control testing may be required. It also determines the true accuracy of the test jigs and fixtures for the three test methods before testing the harness assembly by measuring a reference copper tube, where the predicted performance of the copper tube can be calculated using the Schelkunoff (1934) equation. It also describes a theoretical technique from which the upper frequency limit of each test method can be determined, and hence the accuracy of the results obtained for the harness and test method