Requirements and features of harness testing in the aerospace industry

1. Overview

High-quality testing is essential for harnesses and cables used in aircraft, rockets, satellites, and space probes. Space development by private companies and venture companies, known as "new space" companies, is also becoming more and more active. As a specialized manufacturer of harness testers, NAC CORPORATION has achievements in harness testing for the aerospace industry.

• ・Lightweight components
• ・Narrow pitch connectors are selected to save space.
• ・Designs that can withstand extreme environments
• ・Reliability is achieved in compliance with various standards and with advanced requirements such as JAXA certification.
• ・All information that can be measured is recorded and stored for a long period of time.
• ・Multiple processes with intermediate and final testing due to the huge size of the harnesses.

2. Testing of cables and wire harnesses in the aerospace 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.
• ・Resistance testing requires measurement at the mΩ level. Therefore, 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.
• ・Both AC and DC withstand voltage tests are performed, but DC tests are 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 aerospace 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.