Level switch with verification capability

摘要

The present invention comprises a novel level switch which may be employed to detect liquid levels within a process vessel. The level switch of the present invention is self validating so that manual testing is not required in order to ensure proper operation and switch calibration. The switch of the present invention may be easily introduced into existing process vessel designs as a replacement for prior art level detection switches with minimal or no retrofitting effort being required. The self validating level switch of the present invention may be connected to a Safety Instrumented System (SIS) such that process control including process shutdowns to avoid overfilling and low-fluid conditions may be accomplished.