PX275

Supported Applications

The PX275 is a rugged, OEM-style differential pressure transmitter that offers up to 6 field-selectable ranges in one unit. Built around a steel panel-mount chassis, it is intended for integration into OEM equipment and building-automation systems where low differential pressure of clean, dry air or inert gas must be measured.

The chassis is enamel coated, 18GA steel in a panel-mount format. Process pressure is applied through 0.2" hose barbs (use ⅜" flexible tubing), and termination is by a screw terminal block. Media compatibility is limited to clean, dry air or inert gas.

Operating Conditions & Performance

Accuracy is ±1.0% FS across the selectable ranges. The operating temperature range is -18 to 80°C, the compensated temperature band is -4 to 65°C, and thermal effects are 0.02% FS/°C. Proof pressure is 10 psi.

Ranges are expressed in inH2O, spanning 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 configured to a range group in which every listed range is field-selectable.

Current-output units (PX275) provide a 4 to 20 mA (2 wire) signal on 12 to 40 Vdc excitation, while voltage-output units (PX278) provide 0 to 5 or 0 to 10 Vdc on 12 to 35 Vdc excitation. The panel-mount chassis measures 127 mm (5.00 in) wide, 57.4 mm (2.25 in) high and 114 mm (4.50 in) deep.

Configuration Options

Each range group is available as a current-output (PX275) model and a voltage-output (PX278) model. The defining capability of each model is its set of field-selectable ranges:

• PX275-0.1DI / PX278-0.1D5V — 0 to 0.1, -0.05 to +0.05 inH2O (factory-sealed low range).
• PX275-01DI / PX278-01D5V — 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.
• PX275-05DI / PX278-05D5V — 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.
• PX275-30DI / PX278-30D5V — 0 to 30, 0 to 15, 0 to 7.5, -15 to 15, -7.5 to 7.5, -3.75 to 3.75 inH2O.

The primary capability split is output type: PX275 models deliver a 4 to 20 mA (2 wire) current loop, while PX278 models deliver a 0 to 5 or 0 to 10 Vdc voltage signal. The models also differ in mass — the PX275 weighs 250 g (0.5 lb) and the PX278 weighs 454 g (1 lb). All variants share the ±1.0% FS accuracy and the clean, dry air or inert gas media limitation.

Key Product Differences

The PX275 OEM differential pressure transmitter is offered in the following orderable models, grouped by selectable range set:

• PX275-0.1DI — current output, 0 to 0.1 and -0.05 to +0.05 inH2O.
• PX275-01DI — current output, selectable ranges 0 to 1.0 through -0.125 to 0.125 inH2O.
• PX275-05DI — current output, selectable ranges 0 to 5.0 through -0.625 to 0.625 inH2O.
• PX275-30DI — current output, selectable ranges 0 to 30 through -3.75 to 3.75 inH2O.
• PX278-0.1D5V — voltage output, 0 to 0.1 and -0.05 to +0.05 inH2O.
• PX278-01D5V — voltage output, selectable ranges 0 to 1.0 through -0.125 to 0.125 inH2O.
• PX278-05D5V — voltage output, selectable ranges 0 to 5.0 through -0.625 to 0.625 inH2O.
• PX278-30D5V — voltage output, selectable ranges 0 to 30 through -3.75 to 3.75 inH2O.

All models are listed with the compatible meters DP24-E, DP25B-E and DP41B-E.