Requirements and features of harness testing in the defense industry

1. Overview

High-quality testing is essential for harnesses and cables used in helicopters, special vehicles, ships, and guidance systems.
As a specialized manufacturer of harness testers, NAC CORPORATION has achievements in harness testing for the defense industry.

• ・Compact, lightweight, airtight, and noise-resistant
• ・Designed to withstand extreme environments.
• ・Reliability is achieved in accordance with the high requirements of various standards (Ministry of Defense standards, MIL, JIS, etc.)
• ・Record and long-term storage of all pass/fail results and all measurable information.
• ・Multiple processes with intermediate and final testing due to the huge size of the harness

2. Testing of cables and wire harnesses in the defense industry

• ・Wiring, resistance, dielectric withstand voltage, and insulation testing are conducted.
• ・The threshold resistance value for the wiring testing is clearly determined. For example : 1Ω or lower for continuity, 10MΩ or higher for open (insulation).
• ・Resistance testing requires measurement at the 1Ω level. In some cases, Kelvin connection (4-wire low-resistance testing) is required to measure and determine the pure conductor resistance of the tested target.
• ・Dielectric withstand voltage testing is conducted for 60 seconds per application. The application method can be either one-to-all or one-to-one scanning.
• ・DC testing is required for long cables because of the influence of capacitive reactance.
• ・Insulation resistance testing is conducted using the scan method or connector-by-connector as required specifications.<
• ・High-quality testing is conducted by specifying the high and low sides of the application, setting different voltages and insulation resistance values for each circuit.
• ・Demand for momentary disconnection testing to check continuity under shock and vibration is also increasing.

3. Operation

• ・A variety of information is involved in the test results. The inspection sheet contains the actual measured values and judgment results of each test for each wire.
• ・The test target is huge, so a wheeled wagon-type tester is installed for the operation.
• ・NAC Corporation's harness testers adopt special semiconductor relays that have no contact life and are very popular in the defense industry.
• ・NAC CORPORATION's testers are maintenance-free and have a low tendency to fail.
• ・NAC CORPORATION also provides quick calibration services to prove traceability.