Age Degradation

Some wire insulation types have well-defined accelerated aging processes, whereas others are rather non-active in terms of standard aging (heat, strain, and humidity). This procedure provides a vetted process for assessing the age degradation process for polyalkene wire. For non-polyalkene insulated wire/cable types, see Thermal Index. Life cycling of polyalkene wire is a three-step process […] Read more

Time/Current to Smoke

When placed under heavy electrical load conditions beyond the designed current carrying capacity, wire/cable will heat and cause damage to the conductor, wire/cable insulation, and potentially other components. At what electrical load the wire begins to degrade and produce smoke varies depending on the conductor material, conductor plating, and insulation. Those wires/cable able to handle […] Read more

Conductor Solderability

Soldering is a common method for wire termination and the adhesion of the solderability is critical for both mechanical and electrical performance. Certain conductor platings, such as tin and silver, are more solderable and thus used for these applications. The solderability of a wire conductor examines how well a solder adheres to a conductor. Any […] Read more

Thermal Index

The long-term thermal stability of wires and cables is important for reliable aircraft performance. Wires used at temperatures at or above the temperature rating can quickly degrade and create the need for premature rewiring of systems. The thermal index test (also known as the Relative Thermal Life and Temperature Index) is based on multiple cycles […] Read more

Humidity – Connectors

Exposure to humidity is among the most common means of electrical equipment degradation. The humidity testing offers a means of assessing the potential for a in-service connector and/or crimped contact degradation due to heat and humidity. The problems are most pronounced on components with significant imperfections in the component plating. This test seeks to assess […] Read more

Resistance to Oil: Insulation and Sheath

This method is intended for use in determining the effect of oil on oil-resisting insulation and sheath of insulated wire and cable. The procedure may be used for determining the resistance of insulation and sheath to oil at any desired temperature. The tensile strength and elongation, or other characteristic used for determining the degree of […] Read more

Thermal Shock

Temperature cycling can cause rapid degradation of wire/cable insulation integrity. This can manifest and insulation splits, cracks, and/or delamination. Often an overlooked test method for assessment, the thermal shock test proves and excellent means of assessing the construction quality of a wire or cable. The test focuses on a single high-temperature to low-temperature exposure and […] Read more

Delamination and Blocking

While on an aircraft, wire/cable may be exposed to high temperatures while in operation. Wire/cable that softens or deforms when exposed to high temperature is a problem for the health of the aircraft and to those that maintain the fleet. Testing for delamination (the separation of layers of insulation) and blocking (adhesion either to a […] Read more

Insulation Wrap Back Test

During normal operation and maintenance cycles wire/cable are subjected to stresses, both mechanical and environmental, that challenge the integrity of wire/cable insulation. The wrap back test subjects wire/cable specimens to a very tight bend diameter in addition to conditioning at elevated temperatures to determine if a specific insulation is prone to cracking. A specimen is […] Read more

Contact Resistance

A potential lossy area in electrical circuits (both for power and signal) is at the contact points. Poor mating, contaminated surfaces, poor crimping, and/or damaged plating can all add resistance to the circuit. A means of assessing this impact is by measuring the contact resistance. Contact resistance refers to the electrical resistance that can be […] Read more

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