Ingress Ratings Sold as Marketing against a Real Test Report
Verify ingress claims using ISO IEC 17025 accredited test reports detailing pre and post electrical insulation checks rather than marketing datasheets.
Dielectric Insulation Resistance
Electrical Barrier
Material properties determine the ability of a non-conductive medium to prevent leakage currents between conductors. Dielectric insulation resistance measures the opposition of an insulating material to the flow of direct current when subjected to a high voltage. It indicates the physical integrity and dryness of the electrical insulation.
The measurement stops being reliable if the test voltage exceeds the material’s breakdown threshold.
Environmental Degradation
Moisture absorption and surface contamination decrease the effectiveness of the insulating barrier over time. High ambient humidity lowers the dielectric insulation resistance by creating conductive paths on the surface of the component. Chemical exposure can also degrade the polymeric structure of the insulator, causing premature leakage.
Regular assessment detects these environmental impacts before catastrophic short circuits occur.
Measurement Method
Applying a stabilized high-voltage direct current across the insulator enables the measurement of minute leakage currents. To determine the dielectric insulation resistance, a megohmmeter measures the current and calculates the resistance using Ohm’s law. The test runs for a set duration, often sixty seconds, to allow capacitive charging currents to subside.
This ensures a stable reading.
Compliance Standard
Industry specifications define the minimum allowable resistance values for electronic and electrical products. These values are verified before shipment.