How can you decide whether to utilize mechanical pressure switches or electronic pressure switches in your application? Each kind of pressure switch has individual advantages, but additionally its limitations. The main differences in functionality between mechanical and electronic pressure switches will be the way the applied pressure is used to use the switch, the type of switch technology, and how the switch point could be adjusted.
Functionality of mechanical pressure switches
A mechanical pressure switch converts the pressure of a fluid into a mechanical movement that actuates the mechanical switch contact in the pressure switch. The switch has the preset or an individually, mechanically adjustable switch point. Each time the switch is actuated, a mechanical pressure switch sends an electrical switching signal, but will not need a voltage supply.
Ordinarily, mechanical pressure switches are simple devices which are either created for cost-effective applications or optimised for long-term use, based on how usually the switching signal should be transmitted. The switches are thus designed either for a minimal application rate (hardly any switching cycles e.g. in safety applications) or for a higher application rate (frequent switching changes e.g. in process control). The hysteresis is usually not adjustable, thus the reset point for switching cannot be configured and is preset by factory setup.
Mechanical pressure switches can be used to switch high currents, such as pumps and drives. However, mechanical contacts often have problems switching the very low voltages in PLCs and modern electronics, unless expensive, gold-plated switch contacts are used.
Functionality of electronic pressure switches
An electronic pressure switch generates electronic switching signals and, very often, also yet another, analogue output signal proportional to the pressure. They’re either programmed at the factory to the required switch points or they feature a programming interface with integrated display and buttons.
Electronic pressure switches have integrated, programmable logic. Demoralizing permits the switch points and the output signal to be adapted to the application-specific needs. Delay time, switch point, reset switch point, hysteresis or window function, normally closed or normally open, and more functions could be programmed in modern electronic pressure switches.
The local display of an electric pressure switch also provides a continuous pressure indication and shows whether the switch outputs are active or not. Finally, modern technologies, like the use of IO-Link, enable programming remotely via signal cables.
Note
Further information on mechanical pressure switches and electronic pressure switches are available on the WIKA website.
Also read our articles
Mechanical vs electronic pressure switches: Application areas
Mechanical pressure switches: So how exactly does one set the switch point?
Pressure switches in booster pumps