Greystone UPB1AR Ultra-Low Pressure Transmitter, Analog, 1 or 0.5 in WC / 250 or 125 Pa, Relay, Polycarbonate

Greystone UPB1AR is an ultra-low differential pressure transmitter for dry air or clean inert gas, with a backlit LCD. This analog model supports 1 or 0.5 in WC and 250 or 125 Pa pressure magnitudes, with selectable 0 to full-scale or bidirectional +/-full-scale operation. The A output option provides a field-selectable 4-20 mA (three-wire), 0-5 Vdc or 0-10 Vdc analog signal. The current output supports a maximum 750 ohm load; voltage output requires a minimum 2,000 ohm load.

The B enclosure option is grey polycarbonate with a hinged, gasketed cover, rated IP65 and NEMA 4X. Mount using the base mounting holes. The transmitter can be mounted in any position; typical installation is on a vertical surface with the pressure ports and cable entrance at the bottom. Avoid severe vibration, excessive moisture and kinked pressure tubing.

The R option includes a normally open SPST relay rated 2 A at 120 Vac or 30 Vdc. Upper and lower alarm trip points are adjustable over the selected pressure range, with a relay delay of 0-10 minutes. Response time is selectable from 1-60 seconds through the local menu. Auto-zero is available by pushbutton or the remote auto-zero input. The LCD displays pressure in in WC or Pa, with enable, disable or automatic backlight settings.

Accuracy is +/-1% full scale of the selected range at 22 C (72 F), including hysteresis, non-linearity and repeatability. Power input is 24 Vac/Vdc, +/-10%, with a maximum specified consumption of 37 mA. Operating conditions are 0-50 C (32-122 F) and 0-95% RH, non-condensing. The device includes reverse-voltage protection and output-limited protection circuitry.

Screw terminals accept 14-22 AWG wiring. Pressure connections use 6.35 mm (1/4 in) nylon barb fittings for 3.175-4.762 mm (1/8-3/16 in) inside-diameter tubing. The enclosure provides an opening for 1/2 in NPT conduit or a suitable cable gland. Follow the manufacturer installation and model-specific wiring instructions.