Differential Pressure Transmitters

How a differential pressure transmitter works

The transmitter senses pressure at two ports and outputs a signal proportional to the difference between them, rather than either pressure alone. That single number tells you how blocked a filter is, how much air or liquid is flowing, or whether a room is holding its pressure relative to a corridor. Ranges run from a few pascals for clean rooms up to several bar for liquid circuits, so the sensor and its zero stability have to match the application.

Choosing a differential pressure transmitter by medium

• Air and gas, HVAC or clean room: the Produal DPT series, including the high-accuracy DPT-Priima at ±0.4% ±0.4 Pa, and Modbus models for BMS integration; see air differential pressure transmitters.
• Air and gas, industrial: Beck 982R, 984, 985 and 990 with selectable ranges and 0 to 10 V or 4 to 20 mA outputs, also on the air page.
• Precise low ranges: Halstrup-Walcher P 26, P 34 and PU/PI, from 10 Pa, also on the air page.
• Water and other liquids: the Beck 988, 0 to 2 bar up to 0 to 10 bar; see liquid differential pressure transmitters.
• Process flow and level: the Trumen TFDP-70 smart DP transmitter, ±0.075% FS, on the air page alongside the industrial models.

What to specify

Give us the following and we'll confirm the right model:

• Pressure range: in pascals, mbar or bar.
• Medium: what the transmitter will see.
• Output: analogue or Modbus.
• Display: whether one is required.
• Hazardous area: if it applies, see our flameproof differential pressure transmitters in the ATEX & Flameproof category.