Mechanical vs. electronic pressure switches: Functionality

How do you decide whether to utilize mechanical pressure switches or electronic pressure switches in the application? Each kind of pressure switch has individual advantages, but additionally its limitations. The main differences in functionality between mechanical and electronic pressure switches are the way the applied pressure is used to operate 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 into a mechanical movement that actuates the mechanical switch contact in the pressure switch. The switch has either a preset or an individually, mechanically adjustable switch point. Every time the switch is actuated, a mechanical pressure switch sends an electrical switching signal, but does not need a voltage supply.
Ordinarily, mechanical pressure switches are simple devices that are either designed for cost-effective applications or optimised for long-term use, depending on how often the switching signal must be transmitted. The switches are thus designed either for a minimal application rate (hardly any switching cycles e.g. safely applications) or for a higher 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 for example pumps and drives. However, เกจแรงดันลม 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 electric pressure switch generates electronic switching signals and, frequently, 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. This enables 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 local display of an electric pressure switch also offers a continuous pressure indication and shows whether the switch outputs are active or not. Lastly, modern technologies, like the usage of IO-Link, enable programming remotely via signal cables.
Note
More info on mechanical pressure switches and electronic pressure switches are available on the WIKA website.
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Mechanical vs electronic pressure switches: Application areas
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