The SureTest™ is a local, manual check feature. It allows the operator to simulate a high level in order to check the operation of the switch, without breaking the pressure boundary.
The SureTest™ is a local, manual check feature. It allows the operator to simulate a high level in order to check the operation of the switch, without breaking the pressure boundary. By extending the pressure tube, and raising the position of the switch enclosure, the SureTest™ housing can be installed between the switch enclosure and the chamber/tank.
Within the SureTest™ housing is a high-strength, rare earth magnet, that surrounds and moves along the outside of the pressure tube. Inside the pressure tube, connected to the primary magnet within the switch enclosure (responsible for actuating the switch mechanism), there is another high-strength, rare earth magnet, that moves with the level. By pulling down on the handle, the arm within the housing pivots up. Directly attached to the end of the arm is the magnet external to the pressure tube, getting pulled up with the arm. When the external magnet comes in proximity to the internal magnet they couple and start to move up together. Since the internal magnet is tied to the primary magnet, the entire assembly gets lifted up as it would with a rising fluid level. This motion causes the primary switch magnet to pass and actuate the secondary switch magnet (see ‘Principle of Operation: Switch Mechanism’ section). Releasing the handle allows the springs within the SureTest™ housing to reverse the motion, resetting the switch and returning the unit to its original position.