PX274

Supported Applications

The PX274 is a rugged differential pressure transmitter with field-selectable ranges, designed for industrial low differential pressure measurement. It is intended for use with clean, dry air or inert gas, making it well suited to air-quality, room-pressure and building-automation duties where accurate low-pressure sensing is required.

Housed in an enamel coated, 18 GA steel enclosure rated NEMA 4 (IP65), the transmitter supports up to 6 selectable ranges in a single unit and includes protection against short circuit and reverse polarity. Pressure is connected through 0.2" hose barbs (use ⅜" flexible tubing). An optional static pressure probe, PX270-PROBE, is available at 101.6 mm (4") length.

Operating Conditions & Performance

Accuracy is ±1.0% FS across the selectable ranges. The operating temperature range is -18 to 80°C, with a compensated temperature band of -4 to 65°C and thermal effects of 0.02% FS/°C. The unit withstands up to 10 psid overpressure without zero shift, and proof pressure is 10 psi.

Measurement ranges are expressed in inH₂O and span from the most sensitive band (0 to 0.1 inH₂O, with a bi-directional option of -0.05 to +0.05 inH₂O) up to 0 to 30 inH₂O. Each unit is field-configured to a specific range group, and every range within that group is selectable in the field. Media compatibility is limited to clean, dry air or inert gas.

Termination is by screw terminal. Current-output units carry the PX274 designation and provide a 4 to 20 mA (2 wire) signal on 12 to 40 Vdc excitation; voltage-output units carry the PX277 designation and provide 0 to 5 or 0 to 10 Vdc on 12 to 35 Vdc excitation. The transmitter weighs 454 g (1.0 lb).

Configuration Options

The lineup is organised by range group, and within each group both a current-output (PX274) and a voltage-output (PX277) model exist. The distinguishing capability between models is the set of field-selectable ranges each provides:

• PX274-01DI / PX277-01D5V — 0 to 1.0, 0 to 0.5, 0 to 0.25, -0.5 to 0.5, -0.25 to 0.25, -0.125 to 0.125 inH₂O.
• PX274-05DI / PX277-05D5V — 0 to 5.0, 0 to 2.5, 0 to 1.25, -2.5 to 2.5, -1.25 to 1.25, -0.625 to 0.625 inH₂O.
• PX274-30DI / PX277-30D5V — 0 to 30, 0 to 15, 0 to 7.5, -15 to 15, -7.5 to 7.5, -3.75 to 3.75 inH₂O.
• PX277-0.1D5V — 0 to 0.1, -0.05 to +0.05 inH₂O (voltage output, factory-sealed low range).

The essential capability split is output type: PX274 models deliver a 4 to 20 mA (2 wire) current loop, while PX277 models deliver a 0 to 5 or 0 to 10 Vdc voltage signal. All variants share the ±1.0% FS accuracy, the NEMA 4 (IP65) enclosure and the clean, dry air or inert gas media limitation.

Key Product Differences

The PX274 differential pressure transmitter is offered in the following orderable models, grouped by their selectable range set:

• PX274-01DI — current output, selectable ranges 0 to 1.0 through -0.125 to 0.125 inH₂O.
• PX274-05DI — current output, selectable ranges 0 to 5.0 through -0.625 to 0.625 inH₂O.
• PX274-30DI — current output, selectable ranges 0 to 30 through -3.75 to 3.75 inH₂O.
• PX277-0.1D5V — voltage output, 0 to 0.1 and -0.05 to +0.05 inH₂O.
• PX277-01D5V — voltage output, selectable ranges 0 to 1.0 through -0.125 to 0.125 inH₂O.
• PX277-05D5V — voltage output, selectable ranges 0 to 5.0 through -0.625 to 0.625 inH₂O.
• PX277-30D5V — voltage output, selectable ranges 0 to 30 through -3.75 to 3.75 inH₂O.

All models are compatible with the DP24-E, DP25B-E and DP41-E meters, and can be paired with the PX270-PROBE static pressure probe accessory.