THE SERIES GSTC CARBON MONOXIDE/NITROGEN DIOXIDE GAS TRANSMITTER monitors the gas concentration in underground parking garages and loading docks. The carbon monoxide transmitter is used to measure the exhaust of gasoline engines, while the nitrogen dioxide transmitter is used for diesel engines. The Series GSTC is compatible with either BACnet or Modbus® communication protocol, allowing the transmitter to be used with almost any building management controller. The GSTC output is communicated over an RS-485 wire via BACnet or Modbus® communication protocol. To maximize the accuracy of the Series GSTC, the sensor can be field-calibrated using the A-449 remote LCD display. When the sensor reaches the end of its life, the display will indicate that the sensor needs to be replaced. BACnet and Modbus® communication protocol recommend limiting the number of nodes in any segment to 32. Therefore, the transceiver may be rated at one unit load. Fractional loads are also acceptable. The Series GSTC accounts as an eighth of a load on the MS/TP network.

Approvals:
• CE Approval
• RoHS Letter of Compliance

Features:
• Industrial grade replaceable CO or NO2 sensors
• Field selectable BACnet or Modbus® communication on GSTC models
• Integral LCD display option
• Service display tool for set-up and calibration of models without a LCD

Applications:
• Parking Garages
• Loading Docks
• Mechanical Room Monitoring

Specifications:

Sensor:	Field replaceable electrochemical, 4 years typical lifespan.
Range:	CO: 0 to 500 PPM, NO2: 10 PPM
Output drift:	<5% per year in air.
Coverage area:	5000 to 7500 sq ft typical.
Accuracy:	CO: 2% FS, NO2: 3% FS, at the time of calibration.
Resolution:	CO: 1 PPM; NO2: 0.1 PPM
Temperature Limits:	-4 to 122°F (-20 to 50°C).
Storage Temperature:	For best sensor life, 32 to 68°F (0 to 20°C).
Humidity Limits:	15 to 90% RH constant; 0 to 99% RH intermittent.
Response Time:	<45 s to 90% CO, <25 s to 90% NO2.
Span and Zero Adjustment:	Via pushbutton, using optional A-449 display. Zero only via BACnet or MODBUS® communication protocol.
Housing:	UV resistant glass filled polycarbonate.
Output Signals:	BACnet MS/TP, MODBUS® RTU, or MODBUS® ASCII (switch selectable) communication protocol.
Power Requirements:	10 to 36 VDC or isolated 21.6 to 33 VAC.
Electrical Connection:	Removable terminal block, knock outs for conduit fitting.
Calibration:	Via pushbuttons using A-449 auxiliary display. Span gas concentration is field selectable.
Enclosure Rating:	IP64.
Weight:	1 lb (0.45 kg).
Agency Approvals:	CE.