Pressure Transducers: Types and How To Select



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How to Select Pressure Transducers:

Know your application-specific requirements based on the following parameters...

  • Pressure Range -- Max Working Pressure: PSI, Bar, in H2O
  • Min. Accuracy (%Full Scale): 0.05% FS, 0.25% FS, 0.5% FS, 1% FS
  • Pressure Type: Gage, Absolute, Differential, Vacuum, Bidirectional
  • Transducer Style: Differential, Flush Diaphram, General Purpose, Heavy Duty/Industrial, High Stability, PC Board-Mountable, Special Purpose (see below)
  • Output: Millivolt, Volt, Milliamp, RS232
  • Approval or Compliance Agency Listings: CE, FM, CSA, MSHA, NIST, MIL

Types of Pressure Transducers:

  • Millivolt Output Pressure Transducers: The least costly pressure transducers, with a low-output signal, the actual output is directly proportional to the pressure transducer input power or excitation.
  • Voltage Output Pressure Transducers: This type includes integral signal conditioning for a much higher output, usually 0-5Vdc or 0-10Vdc, and can be used in a harsher/industrial environment.
  • Current Output Pressure Transducers and Transmitters: Best used when the signal must be transmitted long distances. It's not uncommon to use these transducers in applications where the lead wire must be 1000 ft. or more.
  • Differential Pressure Transducers: Frequently used in flow measurement where they can measure the pressure differential across a venturi, orifice, or other type of primary element.
  • Other types of Pressure Transducers: A variety of pressure transducers with special features for many non-standard applications.

Examples of Main Specifications:

Voltage Output
Excitation: 24 Vdc @ 15 mA (7 to 35 Vdc for 5 V output, 12 to 35 for 10 V output)
Output: 0 to 5 Vdc or 0 to 10 Vdc ±1.5%(3-wire)
Zero Balance: 0 Vdc ±2% FSO
4 to 20 mA output
Excitation: 24 Vdc (7 to 35 Vdc) reverse polarity protected
Output: 4 to 20 mA ±1% FSO (2-wire)
Zero Balance: 4 mA ±2% FSO
Maximum Loop Resistance: 50 x (supply voltage -10) Ω
Agency Approvals: FM Intrinsically Safe: IS/I.II.III/1/CDEFG - Standard FM Hazardous Location: S/I/1/ABCD; Optional-Must be specified at time of order (cable style in Absolute or Sealed gauge pressure only); MSHA (Optional). e.g.,: EMC: CE compliant to EN61326, 1997 ANNEX A harmonized heavy industrial transmitter specification.

Examples of Other Specifications:

Accuracy: 0.25% BFSL (including linearity, hysteresis and repeatability)
Operating Temperature: -54 to 121°C (-65 to 250°F)
Compensated Temperature: -20 to 80°C (-4 to 176°F)
Thermal Effects: 0.04% FS/°C (0.02% FS /°F)
Proof Pressure: 150% of rated pressure
Burst Pressure: 300% range max.
Response Time: 2 mS typical
Vibration Sensitivity: At 20 g peak sinusoidal vibration from 10 Hz - 2000 Hz (1.2" D.A.), the output not to exceed 0.04% FS/g for 15 psi range to 0.005% FS/g for 100 psi and above
Natural Frequency: >35 kHz for 100 psi range
Gage Type: Diffused silicon strain gages
Sensing Element: 4 active arm bridge with hermetically sealed thick film strain gages
Wetted Parts: 316 SS, borosylicate glass, silicon nitride, epoxy
Pressure Port: 1/4-18 NPT
Electrical Connections:
1 m (36") shielded 4-conductor cable; PVC insulated cable; DIN 43650 Plug Connector Supplied
Weight: 128 g (4.5 oz)

Related pages: Pressure Transducers and Transmitters | Load Cells | Flow Meters