A. Core Selection Parameters

1. Measurement Type

• Gauge Pressure: For conventional industrial scenarios (referenced to atmospheric pressure).
• Absolute Pressure: For vacuum or sealed systems (referenced to vacuum zero point).
• Differential Pressure: For flow and liquid level monitoring (e.g., orifice plate flowmeters).

2. Range

• Best Practice: Conventional operating pressure should account for 50%–70% of the range (e.g., select a 0–16 bar range for an actual pressure of 10 bar).
• Overload Capacity: Reserve a 1.5× safety margin (e.g., select a 0–25 MPa range for a peak pressure of 24 bar).

3. Accuracy Class

• General Scenarios: ±0.5% FS (e.g., process control).
• High-Precision Requirements: ±0.1%–0.25% FS (e.g., laboratories or energy metering).

4. Process Connections

• Threaded Type: 1/2"NPT, G1/2, M20×1.5 (for medium-low pressure scenarios).
• Flange Type: DN50/PN16 (for high-pressure or corrosive media).

5. Medium Compatibility

• Contact Materials:
  • General Media: 316L stainless steel diaphragm.
  • Strongly Corrosive Media: Hastelloy C276, tantalum diaphragm.
• Sealing Materials: Fluororubber (≤120℃), polytetrafluoroethylene (acid/alkali resistant).

B. Environmental and Signal Requirements

1. Output Signals

• Analog Type: 4–20mA + HART (compatible with most PLC/DCS systems).
• Digital Type: RS485 Modbus, PROFIBUS PA (requires matching control system protocols).

2. Power Supply

• Standard: 24VDC (two-wire loop power supply).
• Special: 12–36VDC wide voltage (for vehicle-mounted or unstable power grids).

3. Protection and Certifications

• Protection Rating: IP65 (dust/waterproof for outdoor use), IP68 (submersible conditions).
• Explosion-Proof Certification: Ex d IIC T6 (for flammable and explosive environments).
• Industry Certifications: SIL2/3 (safety instrument systems), CE/ATEX (EU mandatory).

C. Scenario-Based Selection Recommendations

1. Liquid Pressure Measurement (e.g., Water Treatment)

• Selection Key Points:
  • Flat diaphragm structure (anti-clogging).
  • Optional flush ring design (to handle impurities)
  • Range covers static pressure + dynamic pressure peaks

• 2. Gas Pressure Monitoring (e.g., Compressed Air)

  • Selection Key Points:
    • Built-in damping adjustment (to suppress pulsation interference)
    • Optional absolute pressure type (to avoid impacts from atmospheric pressure fluctuations)

  3. High-Temperature Media (e.g., Steam)

  • Selection Key Points:
    • Diaphragm materials with temperature resistance ≥200℃ (e.g., ceramic)
    • Install radiators or capillary extensions

      
      

      
      

      
      

      
      

      
      

      

      d. Pitfalls to Avoid

      1. Range Misconceptions

      • Avoid selecting an excessively large or small range: An overly large range reduces accuracy, while an undersized range is prone to overpressure damage.

      2. Medium Compatibility

      • For strongly corrosive media (e.g., chlorine gas, concentrated sulfuric acid), must verify diaphragm materials with reference to the Corrosive Media Selection Manual.

      3. Installation Impacts

      • For liquid measurement, the transmitter should be positioned below the pressure tapping point to prevent air bubble accumulation; for gas measurement, it should be above the tapping point to avoid liquid accumulation.

        

        
        

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