178A Low Differential Pressure Transmitter
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Low Differential Pressure Transmitter alpha" instruments The Model 178A Series are low range differential pressure transmitters. The 178A series has a SS304 front panel and an IP65NEMA 4 rated aluminum die casting enclosure to withstand environmental effects. The Model 178A Series are available for full scale pressure range from 0 to 0.1"WC till 0 to 100"WC. Both unidirectional and bidirectional pressure ranges are offered. The output of Model 178A Pressure Transmitter is 4 to 20 mA. All units are temperature compensated. The accuracy can be 0.6%, 0.4% or 0.25% at room temperature. The patented variable capacitance pressure sensor is constructed by stainless steel and glass, no glue or other organics. That provides excellent performance, corrosion resistance and long-term stability. Model 178A Specifications Performance Data Accuracy* (at room temp) Non-Linearity (BFSL) Hysteresis Non-Repeatability Thermal Effects: Zero/Span Shift (/°F) Compensated Range Maximum Line Pressure Overpressure Stability Warm-up shift Applications: ■ HVAC and VAV Control ■ Clean Rooms and Isolation Rooms ■ Duct Static Pressure Measurement ■ Draft Control and Fume Hood Control ■ Furnace Air Flow Control ■ Power Plant Air Flow Monitor and Control Features • 3-1/2 Digit LCD Display • Incorrect Wiring Protection • 15 PSI Over Pressure • SS304 Front Panel Mounting • Rugged Aluminum Housing Rated NEMA 4/IP65 • RoHS Compliant • Pressure Ranges as Low as 10Pa Only! 15PSI(100kPa) in Positive or Negative Direction for all Ranges Position Effect Each unit is calibrated in the vertical position. For best accuracy, adjust zero of the unit if it is mounted in other position. It is not necessary to adjust the sensitivity. * RSS of Non-Linearity, Hysteresis, and Non-Repeatability. Environmental Data and Physical Description Operating Temperature Storage Temperature Electrical Termination Pressure Fittings Zero & Span Adjustment Pressure Media Enclosure Weight Installation 32 to 140° F(0 to 60°C) -40 to 185° F(-40 to 85°C) Pluggable Terminal Block with PG-9 Strain Relief 3/16", 6.5mm or 8.0mm O.D. Barbed Brass for Push-on Tubing Push button for Zero, Potentiometer for span Typically Air or similar non-conducting Gases Die-cast aluminum, SS304 front panel, rated NEMA 4/IP65. 18OZ/508g Front Panel Mounting Visit us Online: www.alphainstruments.com E-mail: sales@alphainstruments.com 978-264-2966

Electrical Data (Current) Circuit Excitation Output Bidirectional Output at Zero External Load 2-Wire(+EXC, -EXC), Protected against incorrect wiring 16-32VDC(see diagram 2 for maximum loop resistance) 4-20mA 12mA as standard 0-800 OHM * Calibrated with a 250 OHM load and a 24VDC supply voltage Span Factory Setting: ±0.5%FS • ^ 1500 CO s X o □J iooo z £ W ffi 500 o' Q. o o -■ 0 0 10 POWER SUPPLY VOLTAGE * Loop resistance - Wire res. + Receiver res. Diagram 2 Diagram 1 Ordering InformationCode all blocks in table. Example: 178AP0100DA6NA for 178A Transmitter, 0~100Pa Range, Unidirectional,...