The PX291 is no longer available. Please see the PX655 series as a possible
substitute or contact our sales department.
The PX291 Series of differential pressure transmitters is designed to measure low pressures while using little power. A selection of ranges is available to meet most industrial and laboratory applications. The transmitters are housed in a flame-retardant, glass-reinforced polyphenylene oxide case. Electrical connections are made by means of a 3.8" terminal with #6 screws. There are no moving parts and the transducers are virtually position insensitive. The span and zero settings are made via 20-turn potentiometers, for easy and precise adjustments. The pressure sensing element is a differential capacitive cell for the low pressure ranges from 0.1 to 5 inH2O and a piezoresistive chip for ranges above 5 inH2O. Both sensors ensure reliability and long-term stability.
SPECIFICATIONS General: Measures differential, gage pressure or vacuum Excitation: 11 to 32 Vdc reverse polarity protected Voltage Output Models: 0 to 5 Vdc 3-wire, source or sink 3.5 mA, short circuit protected, current draw = 10 mA Current Output Models: 4 to 20 mA, output limited to approximately 3.85 mA at low end and 25 mA at high end Maximum Current Loop Resistance: RL = (Vs - 11) x 50 Accuracy: ±1% includes linearity, hysteresis Calibration: NIST-traceable Operating Temperature: 0 to 45°C (32 to 115°F) Temperature Effects: Zero: ±0.05%/°C Span: ±0.02%/°C Operating Humidity Range: 10 to 90% non-condensing Shock Resistance: 10 g (11 ms) Vibration Resistance: 5 g to 50 Hz Overpressure: See order chart for maximum safe momentary overpressure Media Compatibility: Suitable for air or inert gas Pressure Connection: 3.16" Dia. tube connections with integral filters at both ports, suitable for 1.8" ID TygonR or polyurethane tubing (3 to 4 mm) or 1.4" OD polyethlene tubing (6 mm) Electrical Connection: External 3.8" terminal strip with #6 screws Case Material: Flame-retardant, glass-reinforced polyphenylene oxide Dimensions: 36 H x 76 W x 131 mm L (1.4H x 3.0W x 5.15"L) Weight: 190 g (6.72 oz)
If the measured differential pressure is expected to go from positive to negative, a transducer with offset (elevated zero) should be ordered. The standard models in the order chart have no offset (i.e., at zero differential pressure, the output is 0 Vdc or 4 mA). 2 offset options are available: gAh 1.4 Span Offset At zero differential pressure, the output is 1.25 Vdc or 8 mA Allowable pressure excursion: -33% to 100% of range gBh 1.2 Span Offset At zero differential pressure, the output is 2.5 Vdc or 12 mA Allowable pressure excursion: -100% to 100% of range Examples: PX291-001WD5V-A will have a range of 1"