These active vacuum switch/transmitters provide an inexpensive and straightforward way to control your vacuum system. Use the Pirani sensor switch directly to initiate crossover after roughing, or the diaphragm sensor switch to control backfill pressure on pump and purge operations. Feed the switch output into your PC or PLC and let the digital system make the control decisions based on the output signal.To create a complete vacuum system, choose your vacuum range and sensor type from the table below, and then choose your sensor connection style. Switch/transmitter plugs directly into sensors. Measure high, medium, and low vacuum with Pirani, thermocouple, and diaphragm sensors.