This desktop VOC monitor offers real-time detection of indoor mixed gases with high sensitivity to total volatile organic compounds (TVOC).

Note: All Tongdy monitors and controls ship direct from the factory. Please allow 10-15 business days for shipping and handling.

It simultaneously displays temperature and humidity, providing a comprehensive overview of indoor air conditions. The device features a three-color backlit LCD that clearly indicates air quality levels, accompanied by a selectable buzzer alarm for immediate alerts. An optional on/off output allows integration with a ventilator for automated air control, and an RS485 interface is available for advanced connectivity. Its intuitive display and warning system enable precise air quality management to maintain a healthy environment. The unit includes a handheld remote controller for parameter setup and additional functionality.

• Real-time monitoring of TVOC, temperature and humidity for complete indoor air quality insight

• Built-in semiconductor mixed-gas sensor with 5-year lifespan for long-term reliability

• Detects a wide range of harmful gases, including cigarette smoke, VOCs (formaldehyde, toluene), ethanol, ammonia, hydrogen sulfide, sulfur dioxide and more

• Clear LCD display shows current readings plus a one-hour moving average for accurate trend analysis

• Six-color backlight system aligned with PM2.5 AQI standards for intuitive visual air quality indication

• Three-level color alarm (green/orange/red) with buzzer warning for quick response to poor air conditions

• Provides one relay output to control a ventilator or other air-handling equipment

• Optional Modbus RS485 communication for seamless integration into building management systems

• Flexible design for desktop use or wall mounting in residential, commercial, and industrial settings
  

• Remote control included for parameter setup and additional functionality

Specifications

Gas detection	Highly sensitive to many harmful gases, such as harmful gases from construction and decoration materials, VOCs (like toluene and formaldehyde); Cigarette smoke; Ammonia and H2S and other gases from household wastes; CO, SO2 from cooking and burning; Alcohol, Natural gas, detergent and other bad smells etc.
Sensing element	Semiconductor mix gas sensor of long working life and good stability
Signal update	1s
Warm up time	72 hours (first time), 1 hour (normal operation)
VOC measuring range	1～30ppm ( 1ppm= 1 part per million
Display resolution	0.1ppm
VOC setting resolution	0.1ppm
Temperature & Humidity Sensor	Temperature	Relative Humidity
Sensing element	NTC 5K	Capacitive sensor
Measuring range	0~50℃	0 -95%RH
Accuracy	±0.5℃ (25℃, 40%-60%RH)	±4%RH (25℃, 40%-60%RH)
Display resolution	0.5℃	1%RH
Stability	±0.5℃per year	±1%RH per year
Output	1xRelay output to control a ventilator or air-purifier, max current 3A resistance（220VAC）
Warning alarm	Inner buzzer alarm and also three colors backlit switch as well
Buzzer alarm	Alarm starts when VOC value above 25ppm
LCD backlit	Green—optimal air quality ► enjoy the air quality   Orange—moderate air quality ► ventilation suggested Red—-poor air quality ► ventilation immediately

 

RS485 interface (optional)	Modbus protocol with 19200bps
Operating condition	-20℃~60℃ (-4℉~140℉)/ 0~ 95% RH
Storage conditions	0℃～50℃ (32℉～122℉)/ 5~ 90% RH
Net Weight	190g
Dimensions	130mm(L)×85mm(W)×36.5mm(H)
Installation standard	Desktop  (65mm×65mm or 85mmX85mm or 2”×4” wire box)
Wiring standard	Wire section area <1.5mm2
Power supply	24VAC/VDC，230VAC
Consumption	2.8 W
Quality System	ISO 9001
Housing	PC/ABS fire-proof, IP30 protection
Certificate	CE

 

Downloads

Desktop TVOC Indoor Air Quality Monitor Datasheet