




Dwyer Instruments GSTA-C | Carbon Monoxide Transmitter with universal current/voltage outputs
Gas concentrations in loading docks and subterranean parking garages are monitored using Carbon Monoxide/Nitrogen Dioxide Transmitters, Model GSTA-C, Series GSTA. Diesel engines often employ nitrogen dioxide, while gasoline engines typically use carbon monoxide to measure emissions. The transmitter can be used with nearly any building management controller thanks to its field-selectable current and voltage outputs. The user has the option to set the output range for carbon monoxide units to either 0 to 50 PPM or 0 to 500 PPM. Standard nitrogen dioxide units have a 0 to 10 PPM range. Use the internal dip switches to flip the output so that it reads 20 to 4 mA or 10 (5) to 0 VDC.

Free UAE shipping available
- Specifications
- Features
- Downloads
Accuracy | CO: +/-2% FS NO2: +/-3% FS, at the time of calibration |
Approvals | CE |
Connection | Electrical: Removable terminal block, knocks out for conduit fitting |
Coverage Area | 5000 to 7500 sq ft typical |
Enclosure Rating | IP64 |
Housing | UV resistant glass filled polycarbonate |
Humidity | Limits: 15 to 90% RH constant; 0 to 99% RH intermittent |
Maximum operating temperature | Ambient: -4 to 122°F (-20 to 50°C) |
Output Signal | Switch selectable 4-20 mA (loop powered), 0-5 V @ 5 mA, or 0 to 10 V@ 5 mA; Switch selectable 0 to 5 V / 1 to 5 V and 0 to 10 V / 2 to 10 V; Switch selectable normal or reverse output |
Output | Drift: <5% per year in air |
Power | Current output: 10-35 VDC Voltage output: 15-35 VDC or 15-29 VAC |
Range | CO: Switch selectable 200 or 500 PPM NO2: 10 PPM |
Resolution | CO: 1 PPM NO2: 0.1 PPM |
Response Time | <45 seconds to 90% CO, <25 to 90% NO2 |
Sensor Type | Field replaceable electrochemical, 2 years typical lifespan |
Storage Temperature | For best sensor life, 32 to 68°F (0 to 20°C) |
Weight | 1 lb (.45 kg) |
Zero and Span Adjustments | Via pushbutton, using optional A-449 display |
- To add an optional integrated LCD display, append -LCD to the model number (GSTAC-C-LCD, for example).
- Replaceable CO or NO2 sensors of industrial grade.
- On GSTA models, field-selectable output of voltage or current.
- For versions without an LCD, this service display tool is used for setup and calibration.
Related Products

Dwyer Instruments CMS300-FC | Carbon monoxide transmitter & switch | 0-300 PPM | 4-20 mA/2-10 V (maximum load 2K Ω) | Includes factory calibration certificate

Dwyer Instruments CMS300-FC | Carbon monoxide transmitter & switch | 0-300 PPM | 4-20 mA/2-10 V (maximum load 2K Ω) | Includes factory calibration certificate

Dwyer Instruments CMS300 | Carbon monoxide transmitter & switch | 0-300 PPM | 4-20 mA/2-10 V (maximum load 2K Ω)

Dwyer Instruments CMS300 | Carbon monoxide transmitter & switch | 0-300 PPM | 4-20 mA/2-10 V (maximum load 2K Ω)

Dwyer Instruments GSTC-N-LCD-FC | Nitrogen Dioxide duct mount transmitter with BACnet & Modbus® communication | LCD display | Includes factory calibration certificate

Dwyer Instruments GSTC-N-LCD-FC | Nitrogen Dioxide duct mount transmitter with BACnet & Modbus® communication | LCD display | Includes factory calibration certificate

Dwyer Instruments GSTC-N-LCD | Nitrogen Dioxide Transmitter with BACnet & Modbus Communication with Integral LCD Display

Dwyer Instruments GSTC-N-LCD | Nitrogen Dioxide Transmitter with BACnet & Modbus Communication with Integral LCD Display

Dwyer Instruments GSTC-N-FC | Nitrogen Dioxide transmitter with BACnet & Modbus® communication | Includes factory calibration certificate

Dwyer Instruments GSTC-N-FC | Nitrogen Dioxide transmitter with BACnet & Modbus® communication | Includes factory calibration certificate

Dwyer Instruments GSTC-N-D-FC | Nitrogen Dioxide duct mount transmitter with BACnet & Modbus® communication | Includes factory calibration certificate

Dwyer Instruments GSTC-N-D-FC | Nitrogen Dioxide duct mount transmitter with BACnet & Modbus® communication | Includes factory calibration certificate

Dwyer Instruments GSTC-N-D | Nitrogen Dioxide Duct Mount Transmitter with BACnet & Modbus Communication

Dwyer Instruments GSTC-N-D | Nitrogen Dioxide Duct Mount Transmitter with BACnet & Modbus Communication

Dwyer Instruments GSTC-N | Nitrogen Dioxide Transmitter with BACnet & Modbus Communication

Dwyer Instruments GSTC-N | Nitrogen Dioxide Transmitter with BACnet & Modbus Communication