The HDM series from Stackpole is a through-hole carbon film resistor with proprietary materials and processing that greatly improve the performance of this series in high humidity applications. Typically, film resistors can be susceptible to moisture corrosion when exposed to high humidity conditions. This corrosion will begin as a positive resistance shift initially and eventually will lead to the part becoming open circuit.

The HDM is designed to withstand 1000 hours at 40°C, 93% relative humidity, and 1% rated power which will cause most film resistors to fail quickly. This type of performance is ideal for applications such as industrial controls, automotive controls, aviation and flight equipment, motor controls, and outdoor lighting and security.