An Overview of the Pressure Switch

A pressure switch is a mechanism that senses when a pressure or vacuum has moved out of a predefined range, and shuts down the associated mechanical system, or sounds a warning alarm. A pressure switch is consequently globally utilized to ensure the proper operation of equipment and the safety of personnel.

In residential situations the pressure switch is utilized for everyday functions such as controlling the amount of water pumped into a washing machine, or the correct operation of pool filters and air conditioning systems. In industrial settings in comparison utilizations can range from controlling the pressure in a boiler to ensuring the safe operation of various terrestrial and marine hydraulic systems.

Due to the various different roles that pressure switches play in countless residential and industrial systems, many different types of switches currently exist. These switches generally fall into two categories: electromechanical switches and solid-state switches.

Comparing the Electromechanical and Solid-State Pressure Switch

Traditionally these types of switches have been electromechanical and basically comprised of a sensing element and an electrical snap-action switch. These switches are designed to respond directly to changes in pressure with movement opening (turning off) and closing (turning on) switch contacts. The moving parts associated with these devices however, have made them unsuitable for many applications such as utilization in car transmissions.

Solid-state pressure switches in comparison are becoming increasingly prevalent since their inception in the 1980′s, due to the fact that they have numerous advantages over electromechanical models. One of the main benefits reported regarding solid-state switches is the higher number of possible life cycles, with electromechanical and solid state switches exhibiting approximately 2.5 million and 100 million life cycles respectively.

Solid-state switches also offer a superior resistance to shock and vibration, which negatively affect electromechanical models. These devices are consequently are able to handle a wider range of pressures and are therefore more robust, which causes them to be better suited to sensitive industrial applications where reliability and accuracy are extremely important. The ability of these systems to monitor various different pressures at one time is also advantageous in an industrial situation. This thereby reduces the need for numerous different switches, which would be the case if electromechanical models were utilized for the same application.

One of the major disadvantages regarding the utilization of solid-state pressure switches in industrial settings is the fact that these devices, due to the presence of advanced microprocessors, may become subject to electromagnetic interference. Electromechanical models in comparison are not affected due to the relative simplicity of their design.

Another disadvantage of choosing solid-state switches however, is their high price in comparison to electromechanical devices. Electromechanical devices generally sell for about 45 to 125 dollars, whilst solid-state devices start at 300 dollar. This massive price difference contemporarily ensures that electromechanical switches are still widely utilized.

It can be noted that advances in this type of technology have made them more user friendly and better suited to the countless residential and industrial functions for which they are utilized. It can only be assumed that furtherance of this technology is on the horizon, and that these mechanisms will continue to grow regarding possible utilizations.