The 41C Single-end Pressure Switch offers accurate and reliable protection for vacuum vacuum/pressure processes. Designed for applications where a DC signal output is not required, these switches provide relay outputs that are readily interfaced with alarms, valve actuators, computers, process controllers, load locks and other protection devices. The 41C is referenced to atmospheric pressure. The trip point on can be set to trip above, below (reverse calibration), or exactly at current atmospheric pressure.