Pressure switches have an extremely wide range of characteristics that make them very difficult to describe in a brief and concise manner. The pressure sensing range is from fractions of a pound to many thousands of pounds. In addition they must operate over a very wide temperature range and at much of the same time being subjected to a wide range of chemicals.

Design
Inexpensive switches are available in plastic that are designed for water and other liquids and gasses. These come in a variety of configurations and pressure ranges. In general the pressure sensing element is not sealed against the medium being measured and therefore only those liquids or gasses that will not react with the pressure element can be used. For most other applications the switches are constructed with a barrier between the sensing element and the medium being measured. Many pressure switches are designed to “trip” at a specific pressure and are used as a limit switch or safety relief trigger. In general pressure switches are used in conjunction with other sensing devises in order to provide a complete picture of the process of interest.

Applications
There are a great many applications that only a properly designed pressure sensor can perform the function desired. Some pressure applications can be inferred from other measurements, such as the pressure in an autoclave, by measuring the temperature of the saturated steam. Other areas of pressure can be measured by using the differential levels of a liquid such as the familiar mercury barometer. However most pressure measurements require a sensor that is specifically designed for the application.

Is a pressure switch right for you?
When looking for a pressure switch, it is best to consult with a manufacture that has a range of products or a specially in the range of interest. With some requirements involving high pressure and/or temperatures, it is obvious that the proper selection is paramount. If you believe that a pressure switch is right for your application, we can help recommend a switch that works for you. Our WLC Series Controller can connect with certain pressure switches, giving you the complete system you need to get the job done.