Things to Know about Pressure Sensing Switches

Have you ever wondered what a pressure switch is? Pressure switches may seem very complicated on the surface but if you look at the basic principles and take it slowly, they are not too hard to understand. Here is a closer look at components like Honeywell pressure sensor switches to help you get a better idea of how they work.

What is a Pressure Sensing Component?

Basically, a pressure sensor is used to indicate the presence of pressure and to express this pressure electrically. For many switches, the process is quite simple. Some kind of diaphragm is used which expands in the presence of pressure. This is how many components like Honeywell pressure sensor units work.

Air, gas or fluid enters the diaphragm area, and once pressure reaches a point, the diaphragm expands, eventually closing a set of normally open contacts, closing the circuit. As pressure lowers, the diaphragm drops and this will cause the contacts to eventually break, opening the circuit. In many systems, this is used to automatically control a machine, conveyor or production process. Of course, this same setup can be reversed by using normally closed contacts.

Defining Hysteresis

Hysteresis is the differential between switch contacts where pressure is falling and rising. Adjusting this differential can prevent rapid back and forth switching by placing a lag or delay in the process. With some switches, the hysteresis is not adjustable and is pre-set.


Switching frequency is an important consideration. For example, suppose you want the switch to cycle on and off 120 times per minute. This would be the switching frequency. Cycles on switches can vary a great deal depending on the applications.

Set Point

Set or switching point tolerance refers to the difference between a new switch and one with age. In other words, the effects of age and ambient temperature are taken into consideration.

Choosing the Best Pressure Switch

Even if you check out one brand like Honeywell pressure sensor switches you will find many different types. So how do you choose the best one? These tips may help.

* Identify and note the type of switch currently used.

* Determine failure mode – know the limits of the switch

* Consider upgrading or going to a higher value if the switch has failed prematurely.

* Choose a reputable manufacturer and distributor. Make sure they both are ISO 9000 certified. This ensures the highest quality products and services. This is especially important if you need assistance with choosing the right parts for your inventory.

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