The Vaisala GMW80 Series provides dependable, cost-efficient room measurement for demand-controlled ventilation and indoor air-quality applications.
The Vaisala GMW80 Series is a family of wall-mounted transmitters for measuring carbon dioxide in offices, classrooms, meeting rooms and other occupied spaces. Depending on the model, the transmitter can also measure temperature and relative humidity or provide a passive Pt1000 temperature signal.
Its CARBOCAP® sensor uses an internal reference to maintain stable operation in buildings occupied around the clock. Low self-heating helps reduce temperature-related measurement error, while the product family offers several output and indication choices for common building controllers.
| Model | Measured parameters | Output and indication | CO₂ range |
|---|---|---|---|
| GMW83 | CO₂ and temperature | Voltage outputs | 0 to 2000 ppm |
| GMW83A | CO₂ and temperature | Voltage outputs with colour CO₂ indicator LEDs | 0 to 2000 ppm |
| GMW83D | CO₂ and temperature | Voltage outputs with display | 0 to 2000 ppm |
| GMW83RP | CO₂, humidity and temperature | Voltage outputs and passive Pt1000 | 0 to 2000 ppm |
| GMW83DRP | CO₂, humidity and temperature | Voltage outputs, passive Pt1000 and display | 0 to 2000 ppm |
| GMW84 | CO₂ and temperature | Current outputs | 0 to 2000 ppm |
| GMW84S | CO₂ and temperature | Current output with relay | 0 to 2000 ppm |
| GMW86P | CO₂ and temperature | Current and voltage outputs with passive Pt1000 | 0 to 2000 ppm |
| GMW87 | CO₂ | RS-485 with Modbus RTU | 0 to 5000 ppm |
| GMW88 | CO₂ | Current and voltage outputs | 0 to 2000 or 5000 ppm |
Model availability can vary by market and project quantity. Confirm the exact model code, range and output arrangement before ordering.
| Requirement | Starting point | Selection note |
|---|---|---|
| Standard voltage inputs | GMW83 family | Choose the basic, display, LED or humidity/Pt1000 version required |
| Current inputs | GMW84 or GMW86P | GMW84S adds a relay; GMW86P also provides voltage output and Pt1000 |
| Modbus RTU network | GMW87 | CO₂-only model with an isolated RS-485 interface and 0 to 5000 ppm range |
| CO₂, humidity and temperature | GMW83RP or GMW83DRP | DRP adds a local display; both provide a passive Pt1000 temperature signal |
| Local display | GMW83D or GMW83DRP | Useful for commissioning and local room indication |
| Simple visual CO₂ status | GMW83A | Colour LEDs show the room CO₂ level without a numerical display |
| Relay control | GMW84S | Provides one normally open relay for a configured CO₂ threshold |
| Parameter | Range | Specified performance |
|---|---|---|
| Carbon dioxide | 0 to 2000 or 5000 ppm, depending on model | ±(30 ppm + 3% of reading) at +20 to +30 °C |
| CO₂ stability | Typical HVAC applications | ±(15 ppm + 2% of reading) over five years |
| CO₂ response time | 63% response | 60 seconds; 7 minutes for GMW87 and GMW88 |
| Temperature | 0 to +50 °C | ±0.5 °C from +10 to +30 °C on applicable analogue models |
| Relative humidity | 0 to 95 %RH | ±3 %RH from 0 to 80 %RH at +10 to +30 °C |
| Humidity at high RH | 80 to 95 %RH | ±5 %RH at +10 to +30 °C |
The complete accuracy specification changes with temperature and humidity. Check the latest datasheet when the room operates outside the central range or when a project has a strict uncertainty requirement.
| Specification | GMW80 Series |
|---|---|
| Supply voltage | 18 to 35 V DC or 24 V AC ±20%, 50/60 Hz |
| Analogue outputs | 4 to 20 mA and/or 0 to 10 V, depending on model |
| CO₂ output scale | 0 to 2000 or 5000 ppm, depending on model |
| Temperature output scale | 0 to +50 °C |
| Humidity output scale | 0 to 100 %RH |
| Fieldbus | Isolated RS-485 with Modbus RTU on GMW87 |
| Relay | One SPST normally open relay on GMW84S; maximum 50 V AC/DC, 500 mA |
| Operating environment | 0 to +50 °C and 0 to 95 %RH, with dew point below +30 °C |
| Enclosure rating | IP30; IP64 for GMW87 and GMW88 |
| Connections | Screw terminals accepting wire up to 2 mm² / AWG 14 |
| Application | Measurement purpose | Useful option |
|---|---|---|
| Offices and meeting rooms | Adjust outdoor-air supply according to occupancy-related CO₂ | Voltage or Modbus output to the building-management system |
| Classrooms and training rooms | Support indoor-air-quality monitoring and ventilation control | Display or colour CO₂ indicator for local visibility |
| Retail and public spaces | Reduce unnecessary ventilation while maintaining an appropriate occupied-space condition | Select the output that matches the installed controller |
| Comfort monitoring | Combine CO₂ with humidity and temperature | GMW83RP or display-equipped GMW83DRP |
| Standalone threshold control | Switch an external input when CO₂ reaches the configured level | GMW84S relay model |
| Selection point | GMW80 Series | GMW90 Series |
|---|---|---|
| Product position | Cost-efficient family for standard demand-controlled ventilation and indoor air-quality measurement | Higher-performance family for demanding HVAC and green-building projects |
| Measured parameters | CO₂ only, CO₂ plus temperature, or CO₂ plus temperature and humidity depending on model | CO₂ and temperature on all models, with humidity added on R models |
| CO₂ range | 0 to 2000 ppm on most models; selected models support 0 to 5000 ppm | 0 to 5000 ppm |
| Best CO₂ accuracy at +20 to +30 °C | ±(30 ppm + 3% of reading) | ±(30 ppm + 2% of reading) |
| Humidity sensor | Vaisala INTERCAP® on humidity models | Vaisala HUMICAP® 180R on R models |
| Outputs | Voltage, current, relay, passive Pt1000 or Modbus RTU options depending on model | Voltage, current or galvanically isolated Modbus RTU options |
| Local indication | Display or colour CO₂ indicator available on selected models | Display available on D models; GMW93RA adds a CO₂ LED indicator |
| Maintenance | Low-maintenance CARBOCAP® design; replaceable GM10 CO₂ module | Field-exchangeable calibrated CO₂, temperature and humidity/temperature modules |
| Choose GMW80 when | A cost-effective standard HVAC model provides the required measurements, range and output | — |
| Choose GMW90 when | — | The project needs a consistent 0 to 5000 ppm range, higher accuracy or exchangeable calibrated modules |
| Product information | GMW80 models are detailed on this page | Explore Vaisala GMW90 |
| Product | Installation | Best starting point when |
|---|---|---|
| GMW80 Series | Room wall | You need cost-effective room CO₂ measurement with model-specific temperature, humidity, display, relay or fieldbus options |
| GMW90 Series | Room wall | You need higher CO₂ accuracy, a consistent 5000 ppm range or exchangeable calibrated modules |
| XMW85 | Room wall | You need Modbus room measurement of CO₂, humidity and temperature in one device |
| GMD110 | Ventilation duct | The CO₂ measurement point is inside a supply or return-air duct |
| Origo10 | Wall, duct or remote probe | You need a newer modular HVAC platform with replaceable probes and wider protocol choices |
| Product information | Explore Vaisala GMW90 Explore Vaisala XMW85 Explore Vaisala GMD110 Explore Vaisala Origo10 | |
Seacom Process Instruments supplies and supports the Vaisala GMW80 Series CO₂, humidity and temperature transmitters in Malaysia for demand-controlled ventilation, offices, classrooms, meeting rooms, commercial buildings and other indoor air-quality applications.
Our team can help select the correct GMW80 model, measured parameters, CO₂ range, voltage, current, relay, Pt1000 or Modbus output, display option and installation position. We can also assist with commissioning, controller integration and replacement GM10 measurement modules.
Selecting a GMW80 model? Send us the room type, expected occupancy, required measurements, CO₂ range, controller input, supply voltage, display preference and building-management protocol.
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