Effects of Temperature on Reed Switches and Magnets

The typical operating temperature range for reed contacts spans from -40°C to +200°C, but abrupt temperature changes can potentially damage the glass-to-metal seals due to thermal stress, even though the metal alloy and the glass have similar coefficients of thermal expansion.

In environments where Reed Switches, Reed Sensors, and Magnet Sensors are exposed to high temperatures, understanding their thermal behavior is critical. Elevated temperatures cause the Reed Blades to diminish in their magnetic flux carrying capacity, thereby reducing the sensitivity of Reed Switches, and increasing the AT band. Consequently, to achieve actuation, magnets must be stronger or brought closer to the device. Additionally, it should also be considered that magnets themselves weaken as temperatures rise, losing their magnetism permanently at their Curie point.

Conversely, at lower temperatures, both Reed Switches and magnets exhibit increased sensitivity and strength respectively, making them more responsive to magnetic fields, and there is a decrease in the AT band. When both the magnet and the reed switch are subjected to decreases in temperature, the overall actuating distance decreases. Do contact us for more information about the percentage of operator ampere turn changes with temperature for a particular product.

To optimise performance in high temperature settings, it’s advisable to select sensors with lower magnetic sensitivities (lower Operate Bands) and use stronger magnets. This approach minimizes the impact of gradual temperature changes on actuation distances and ensures consistent operation without the risk of non-operational states. Read more about AT band selection.

By carefully considering these factors, engineers and designers can effectively mitigate the effects of temperature variations on reed switch and reed sensor performance, enhancing reliability and longevity in challenging operational environments. This proactive approach not only safeguards against potential failures due to thermal fluctuations but also maintains the integrity and efficiency of Reed Switches and similar magnetic sensors across diverse industrial applications.