The Model 178 Series are low range differential pressure transmitters. Each unit features a push-activated ZERO function and an associated LCD display. With a convenient push button, the zero calibration can be performed without any additional equipment. It is with NEMA 4 (IP-65) rated aluminum enclosures, they are very rugged and very reliable. The Model 178 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 178 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. alpha" instruments 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 • Push Button Zero Calibration • 15 PSI Over Pressure • Incorrect Wiring Protection • Rugged Aluminum Housing Rated NEMA 4/IP65 • RoHS Compliant 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 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. Operating Temperature Storage Temperature Electrical Termination Pressure Fittings Zero & Span Adjustment Pressure Media Enclosure Weight Installation Environmental Data and Physical Description 32 to 140° F(0 to 60C) -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, rated NEMA 4/IP65. 11.5OZ/330g There are two 0.165 inch dia. mounting holes inside the enclosure. Two M4 X 12 pan head screws with washers and nuts are included in the box. See Diagram 1 for outline and dimensions. Stainless steel mounting plate with tabs is optional. Visit us Online: www.alphainstruments.com E-mail: [email protected] 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 DIMENSIONS ARE IN: Inn] * A CURRENT DUTPUT UNIT IS SHDWN, Diagram 1 Code all blocks in table. Example: 178W00R1DA6NA for 178 Transmitter,...