Unrestricted Shrinkage

This test evaluates the radial shrinkage of a heat shrink insulation sample to ensure the insulation shrinks to the appropriate dimensions as identified in the detail specification. There are two methods with which this test may be performed: Unsupported – The heat shrink sample is placed on a tray in the oven. Supported – The […] Read more

Water Pressure

Connectors that are designed to resist pressure and leakage due to water exposure must be capable of doing so over an extended duration. The water pressure test is performed by submerging a number of connector samples in six feet of tap water for a period of 48 hours. Half of the connectors are mated throughout […] Read more

Wall Thickness

A sample of heat shrink insulation is exposed to an elevated temperature and allowed to fully shrink to its reduced size (Unrestricted Shrinkage, method 5.5), after which the thickness is measured by one of the three methods presented in the standard: Micrometer Method – A smooth gauge rod of known diameter is used as a […] Read more

Wire Fusing Time

A test sample wire is strung horizontally such that it hangs without resting on any surface. A current 2.5 times that of the “free air rated current” is applied to the sample via a DC power source. The sample is held at this constant current until a current interruption (open circuit) occurs with a maximum […] Read more

Wire Identification Printed Marking and Location

It is important that wires involved in a large EWIS system be easily and uniformly identifiable by the manufacturer’s markings. This test entails a visual examination of the identification markings on a wire sample. The identification marking must include the following information in the correct order: Detail specification designator Wire gauge Color designator(s) of insulation […] Read more

Reverse Current Leakage

The purpose of a diode in an electrical circuit is to ensure that current is only allowed to flow in the correct direction. In other words, it acts as a conductor in one direction and as an insulator in the other. The reverse current leakage test evaluates this function by applying a reverse-biased voltage to […] Read more

Safety Wire Hole Pullout

Safety wires are responsible for maintaining the position of a cable/ wire harness on an aircraft and must be able to endure forces due to turbulence or repeated maintenance. This test evaluates the ability of a connector to withstand pulling forces from a safety wire at the location of the safety wire hole. A standard […] Read more

Mutual Capacitance

This test measures the funtional capacitance between a pair of insulated wires within an multi-pair cable. Capacitance measurements are made between the two conductors under test and between each conductor and the components not under test (shield, other conductors) shorted together. These values are then used to calculate the mutual capacitance for the pair within […] Read more

Mutual Inductance

It is critical that signal-carrying conductors within a larger cable construction each be able to effectively perform their separate functions without electrical interference. A source of electrical interference can distort a signal carried on a wire, drastically affecting the functionality of the system. The mutual inductance test measures the effectiveness of the insulation on inner […] Read more

Nitric Acid Immersion (Acid Resistance)

The Nitric acid immersion test determines the ability of a wire’s insulation to resist breakdown in the presence of a strong acid. Test samples are submerged in red fuming nitric acid for a duration of 8 hours. Resistance to the acid is determined via a wet dielectric test – any dielectric breakdown is considered a […] Read more

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