In industrial automation control, the selection of pressure sensors directly determines system stability and measurement accuracy. Faced with a wide range of products from various brands and models, how can you quickly pick the most suitable one for your project? Today, taking the ZW-PM Series Digital Display Pressure Sensor (RS485 Version) as an example, we will walk you through the key selection criteria step by step.
1. Confirm the Measuring Range
First, clarify the pressure range of the measured medium. This series covers a broad measuring range from -0.1 MPa to 100 MPa, catering to vacuum, micro-pressure, normal pressure and high-pressure applications. Examples are as follows:

• 0–1.6 MPa for air compression systems
• 0–40 MPa for hydraulic systems
• -100–0 kPa for negative pressure scenarios

Notes: Measurements below 5 kPa are only applicable to dry gas; only M20×1.5 thread is available for measuring ranges of 60 MPa and above.
2. Choose the Accuracy Class
Two accuracy grades are offered for this sensor: 0.5%FS (standard) and 0.2%FS (high precision). 0.5%FS meets the demands of general industrial control, while 0.2%FS is recommended for metering or precision regulation scenarios.
3. Verify Output Signal and Communication Protocol

This model is equipped with an RS485 interface and adopts the ModBus-RTU protocol, supporting communication distances up to 2000 meters. It can seamlessly connect with PLCs, industrial touch screens, cloud platforms and other equipment. If your existing system runs on the ModBus protocol, this sensor can greatly simplify system integration.

4. Factor in Medium and Working Environment

• Medium Compatibility: Compatible with gases and liquids that do not corrode stainless steel
• Operating Temperature: Standard version from -20℃ to 60℃; high-temperature variant up to 150℃
• Ingress Protection: IP65 all-stainless steel housing with dustproof and waterproof performance, suitable for outdoor and humid working conditions

5. Extra Functions & Customization Options

• Built-in LCD screen for real-time pressure value reading
• Configurable upper/lower limit alarms, backlight duration and unit switching (Pa/kPa/MPa/bar/psi, etc.)
• Optional fittings including water adapters and M20 mounting threads
• Customizable measuring ranges, accuracy grades, thread specifications and more

Conclusion

When selecting sensors, higher price never equals better performance — the best option is always the one that matches your actual requirements. Define your measured medium, pressure range, accuracy standards, communication mode and operating environment, and you can efficiently determine the optimal model. Featuring high integration, versatile functions and reliable performance, the ZW-PM Series serves as an ideal solution for industrial pressure monitoring.

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