Mechanical vs. electronic pressure switches: Functionality

How can you decide whether to use 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 the way the switch point can be adjusted.
Functionality of mechanical pressure switches
A mechanical pressure switch converts the pressure of a fluid right 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. Every time the switch is actuated, a mechanical pressure switch sends a power switching signal, but will not need a voltage supply.
Ordinarily, mechanical pressure switches are simple devices which are either designed for cost-effective applications or optimised for long-term use, based on how usually the switching signal must be transmitted. The switches are thus designed either for a low application rate (hardly any switching cycles e.g. in safety applications) or for a high application rate (frequent switching changes e.g. in process control). The hysteresis is normally 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 low voltages in PLCs and modern electronics, unless expensive, gold-plated switch contacts are used.
Shatter of electronic pressure switches
An electronic pressure switch generates electronic switching signals and, frequently, also an additional, analogue output signal proportional to the pressure. They’re either programmed at the factory to the required switch points or they include a programming interface with integrated display and buttons.
Last have integrated, programmable logic. This 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 much more functions could be programmed in modern electronic pressure switches.
The neighborhood display of an electric pressure switch also provides a continuous pressure indication and shows if the switch outputs are active or not. Finally, modern technologies, including the usage of IO-Link, enable programming remotely via signal cables.
Note
Further information on mechanical pressure switches and electronic pressure switches can be found 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

Leave a Comment