HI PUMP FAQ
Digital pressure instruments can be equipped with a transmitter that sends a signal proportional to a data acquisition system.

What is the difference between a pressure gauge and a pressure switch?

Pressure is one of the most common pump system variables that is measured and provides valuable information about the pump operation and system condition. 

gauge chart switch pressure

IMAGE 1: General comparison of pressure gauges, switches and transducers (Image courtesy of Hydraulic Institute)

A pressure gauge is a device that indicates the pressure in the pumping system locally. Gauges can be mechanical with a dial indication or digital with a numerical reading.

Digital pressure instruments can be equipped with a transmitter that sends a signal proportional to a data acquisition system. This is advantageous when changing the pump or system operation to maintain a pressure set point.

A switch, on the other hand, is a device that, after a deviation of a physical quantity such as pressure, opens or closes a set of contacts. Therefore, it is used for on/off or open/close applications. For example, a pressure switch could be used to start a pump at minimum pressure and then shut it down when a maximum pressure is reached.

For more information on pump system instrumentation and control, refer to HI’s Pump System Assessment Professional (PSAP) Certification Study Guide at www.pumps.org.   

Read more HI Pump FAQs here.