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Gas Sensor Transmitter


The all new GDC-150 transmitter from Bacharach offers detection and protection for a wide range of hazards
including toxic gases such as carbon monoxide (CO), oxygen depletion, combustible gases, refrigerant leaks and
total volatile organic compounds (TVOCs). Analog interfaces allow the transmitter to be connected back to
Bacharach’s GDA Series of controllers (or any other gas detection controller), building management systems or
control systems. The GDC-150 features 4-20 mA or 0-10 VDC linear output signals, an automatic thermal resetting
fuse, RoHS compliant circuit boards and LED indicators for power and open loop.

The onboard alarm LED’s indicate when alarm threshold values are exceeded. The unit can be ordered with an
optional alpha numeric LED display that shows gas concentrations in real time while alarm relays alert personnel
of potential dangers, avoiding incidents and potential hazards.

The GDC-150 is packaged in a rugged, polycarbonate housing for both indoor and outdoor applications. When
leaks occur, the GDC-150 sensors respond quickly and accurately to protect people and property. Automated
calibration and simple maintenance procedures performed in the field allow for continuous operation and
assurance that areas are monitored and protected at all times.


Gases Detected: Carbon Monoxide (CO), Hydrogen Sulfide (H2S), Oxygen (O2), Nitrogen Dioxide (NO2), Ammonia (NH3), Nitric Oxide (NO), Sulfur Dioxide (SO2), Formaldehyde (HCHO), Combustible Gases (LEL), Refrigerants and Total Volatile Organic Compounds (TVOCs)
  CO H2S O2 NO2 NH3 NO SO2
0-200 ppm
1 ppm
0-50 ppm
0.5 ppm
0-25% Vol.
0.1% Vol.
0-10 ppm
0.1 ppm
0-500 ppm
1-2 ppm
0-100 ppm
1 ppm
0-20 ppm
1 ppm
  HCHO LEL (Catalytic) LEL (Solid State) Refrigerants TVOC (PID) TVOC (PID) TVOC (Solid State)
0-10 ppm
0.1 ppm
0-2,000 ppm
1 ppm
0-50 ppm
0.1 ppm
0-300 ppm
1 ppm
0-500 ppm
1 ppm
Detection Principle:
Electrochemical, Solid State, Catalytic Bead, Photoionization Detector (PID)
-4° F to 104° F (-20° C to 40° C)
Relative Humidity:
15-95% RH Non-Condensing
Housing Options:
Standard: Rugged PVC with hinged, secured, drip-proof door
NEMA 4X: Water and dust-tight, corrosion resistant polycarbonate with hinged, secured door
User Interface:
One tricolor LED: Green = power, Red = alarm, Flashing Red = fail
Amber color LED, internal relay coil status indicator (only supplied with relay option)
Alarm Relay:
Optional, one only S.P.D.T. dry contact relay rated 2 amp at 30V
4-20 mA “open loop” indicator (red LED) for remote transmitter
Standard: 4.43” L x 6.5” W x 2.54” D (113 mm x 165 mm x 65 mm) NEMA 4X: 5.05” L x 5.05” W x 3.05” D (129 mm x 129 mm x 77 mm)
Standard: 20 oz (0.57 kg) NEMA 4X: 16 oz (0.45 kg)
Linear 4-20 mA or 0-10 VDC signal, jumper selectable
VDC 3 conductor shielded; VAC 4-conductor shielded
Automatic resetting thermal
12-30 VAC or 16-30 VDC (non-ground reference supply only)
C-Tick Certified

GDC-150 Part Number Configurator 5201-ABCD

  Standard Standard Standard Standard Enclosure Option Feature Option Sensor Option
  5 2 0 1 A B C and D
    0=N/A 0=Nothing 00=N/A
  1=Standard enclosure 1=LED numeric display 01=Carbon Monoxide (C0)
  2=NEMA 4X enclosure 2=Relay 02=Hydrogen Sulfide (H2S)
  3=NEMA 4X enclosure with splash guard 3=Relay and display 03=Oxygen (O2)
    04 = Nitrogen Dioxide (NO2)
  05 = Ammonia (NH3)
  06 = Nitric Oxide (NO)
  09 = Sulfur Dioxide (SO2)
  13 = Formaldehyde (HCHO)
  20 = Combustible Gas (Catalytic)
  28 = TVOC 0-50 ppm (PID)
  29 = TVOC 0-300 ppm (PID)
  30 = Combustible Gas (Solid State)
  31 = Refrigerant (Solid State)
  32 = TVOC (Solid State)

GDC-150 Common Configurations

Part NumberDescription
5201-3001 GDC-150 NEMA 4X, CO, splash guard, no display/relays
5201-3101 GDC-150 NEMA 4X, CO, splash guard and display
5201-3331 GDC-150 NEMA 4X, Refrigerant, display and relays
5201-3305 GDC-150 NEMA 4X, NH3, display and relays
5201-1001 GDC-150 Standard, CO, no display/ relay
5201-1104 GDC-150 Standard, NO2, display
5201-1303 GDC-150 Standard, O2, display and relays
5201-2320 GDC-150 NEMA 4X, Combustible Gas (Catalytic), display and relays
5201-2020 GDC-150 NEMA 4X, Standard, Combustible Gas (Catalytic), no display
5201-1013 GDC-150 Standard, HCHO, no display

GDC-150 Accessories

Part NumberDescription
5209-0004 Splash guard (NEMA 4X only)
5209-0016 Calibration adapter for catalytic sensor
5209-0006 Calibration adapter for all other sensors
5209-0017 Sample draw pump (24 VAC powered)
5209-0018 Sample draw pump (24 VDC powered)
5209-0019 Guard to protect GDC-150 (16 gauge galvanized metal)