For any load switching device, mechanical, magnetic or solid state, for loads other than pure resistive loads, contact protection is required. This is to prevent the switching device from early failure if inrush current is too high. More information about contact protection circuits is available here. Most reed switch and reed sensor based products require contact protection when used with loads where there is a chance of inrush current, for example when switching pumps or motors or when switching capacitive loads. In most cases, contact protection is achieved by designing in to the product, a snubber or RC network that softens the inrush current, thereby protecting the reed contact. Specially designed reed sensors with inbuilt resistors, that are normally used in accurate liquid volume applications also double as devices for contact protection as the same circuits within the reed sensor are modified with a resistor-capacitor network. This simple choice of circuit with built-in resistor are suitable for use in in-rush current applications.