Elevated Temperature Aging

This test determines if the wire insulation can withstand a temperature aging test for a time period at a temperature greater than the insulation temperature rating. The wire must then withstand the bend and wet dielectric tests after the thermal exposure for the specimen to pass the test. This test is sometimes included as part […] Read more

Thermal Endurance

This test determines the ability of the insulation of a firezone or similar wire to resist degradation due to exposure to high temperature. Degradation is judged by change in conductor resistance, cracking during bending, insulation dielectric breakdown, or decreased resistance to fluids. All of these points shall be tested by using 3 foot long samples […] Read more

Wrinkle Test

This test is used to evaluate the quality of insulation and its ability to withstand wrinkling. Wrinkles can occur to insulation when bent back and forth frequently, eventually causing the insulation to deteriorate. The particular concern here is on tape wrapped insulations. During the fabrication process, an adhesive is used to hold the tape wrap […] 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

Humidity Resistance

The humidity resistance test seeks to evaluate the impact of prolonged heat and humidity exposure to wire/cable insulation. This accelerated environmental test is meant to simulate the environmental conditions in Severe Wind and Moisture Prone (SWAMP) areas on aircraft to analyze the possible detrimental effects. A sample is considered to have failed if there has […] Read more

Wrap Back Test

The wrap back examines a wire/cable’s insulation susceptibility to breach when tightly wrapped around itself and exposed to elevated temperatures. This test is usually required in the individual wire specifications as part of the insulation integrity assessment. After the elevated temperature exposure, the specimen is visually examined for any insulation cracks (or delamination in the […] Read more

Insulation Resistance

This test (sometimes referred to as “insulation volume resistivity”) determines the insulation resistance of a finished wire sample. Insulation resistance is of interest in high impedance circuits and as an insulation process quality control test. When used as part of a wire/cable environmental testing, prolonged thermal exposure, and/or extended high voltage testing, changes in the […] Read more

Dielectric Withstand Voltage

The dielectric withstand voltage (DWV), sometimes referred to as the “Voltage Proof Test”, is perhaps one of the most referenced tests when examining wires. The reason is that the test performs the most important part in wire insulation assessment: it determines if the wire insulation is free of breaches (or has been sufficiently degraded such […] Read more

Blocking

This test evaluates if a finished wire/cable specimen will block (stick to itself) when subjected to the specimen’s rated temperature. While on an aircraft, wires may be exposed to high temperatures and it is important to check if the finished wire specimens are prone to blocking (in other words, the test examines whether the wire […] Read more

Cable to Cable Abrasion

This test is used to determine the ability of a sample’s insulation to withstand the rubbing on a similar sample in a vibrational environment. Wires/cables in close contact with one another can rub against each other causing progressive deterioration of the insulation. The impact of how quickly the insulation degrades in a wire-to-wire scenario is […] Read more