Duct air quality (VOC) and CO2 sensor KLQ-CO2 - Modbus
temperature CO2
temperature VOC

Duct air quality (VOC) and CO2 sensor AERASGARD® KLQ-CO2-Modbus

Product group: WG02

In Stock

Usually ships in 1 to 3 days
436,50 €
519,44 € incl. VAT + shipping


Duct air quality (VOC) and CO2 sensor AERASGARD® KLQ-CO2 - Modbus
Patented quality product (patent no. DE 10 2014 010 719.1)The maintenance-free duct sensor AERASGARD® KFTM - LQ- CO2 - Modbus (max. expansion level) and KCO2/ KLQ - CO2/ KFTM - CO2 - Modbus with Modbus connection, automatic calibration, in an impactresistant plastic housing with quick-locking screws, plastic sinter filter (replaceable), incl. mounting flange, optionally with/without display, for determining the CO2-content of the air (0...5000 ppm), of the air quality (0…100 % VOC), the temperature (–35...+80 °C) and the relative air humidity (0…100 % RH). International system of units SI (default) can be changed to imperial (via Modbus). The following parameters can be accessed via the Modbus: Temperature, relative humidity, air quality (VOC), carbon dioxide (CO2) and atmospheric pressure. The sensor is used in offices, hotels, convention centres, apartments, shops, etc. for the purpose of evaluating the indoor climate. This enables energy-saving room ventilation on an as-needed basis, thereby reducing operating costs and improving well-being. One sensor for every 30 m² of space is recommended.

A long-term stable, digital humidity and temperature sensor guarantees exact measurement results. The CO2 measurement is performed using an optical NDIR sensor (non-dispersive infra-red technology). The detection range is calibrated for standard applications such as monitoring residential rooms and conference rooms. The air quality is detected by a VOC sensor (mixed gas sensor for volatile organic substances). This sensor determines the loading of the room air due to contaminated gases such as cigarette smoke, body perspiration, exhaled breathing air, solvent vapours, emissions etc. With regard to the expected air contamination, low, medium or high VOC sensitivity can be selected.
Innovative Modbus sensor with galvanically separated RS485-Modbus-interface, selectable bus termination resistance, DIP switch for setting the bus parameters and bus address in current-free state, internal LEDs for telegram status display, two separate push-in terminals and large three-line display (illuminated; with customised programming in the 7-segment and dot-matrix range). The sensor is factory-calibrated; an environmental precision adjustment by an expert is possible.

Technical details

Voltage supply
24 V AC/ DC (± 10 %)
Power consumption
< 4.4 W/ 24 V DC typical; < 6.4 VA/ 24 V AC typical;
peak current 200 mA
Data points
Air quality (VOC), carbon dioxide (CO2), atmospheric pressure
Sensor, VOC
VOC sensor (metal oxide) with automatic calibration
(VOC = volatile organic compounds)
Measuring range, VOC
0...100 % air quality; referred to calibrating gas;
multi-range switching (selectable via DIP switches)
VOC sensitivity low, medium, high
Measuring accuracy, VOC
± 20 % of final value (referred to calibrating gas)
Service life
> 60 months (under normal load conditions)
depending on the type of loading and gas concentration
Measuring range, CO2
0...5000 ppm
Sensor, CO2
optical NDIR sensor (non-dispersive infra-red technology)
including atmospheric pressure compensation (up to 1100 mbar)
with automatic and manual calibration
Measuring accuracy, CO2
typically ± 30 ppm ± 3 % of measured value
Temperature dependence, CO2
± 5 ppm/ °C or ± 0.5 % of measured value/ °C
(whichever is higher)
Pressure dependence
± 0,13 %/ mm Hg
Gas exchange
by diffusion
Response time
< 2 minutes
Measuring range
0...5000 ppm
Measuring ranges
0...100 % Air quality - VOC sensitivities (low/medium/high)
0...5000 ppm
Ambient temperature
–10...+60 °C
Bus protocol
Modbus (RTU mode),
address range 0...247 selectable
Signal filtering
4 s / 32 s
Process connection
by mounting flange, plastic
(included in the scope of delivery)
Protective tube
PLEUROFORM, material polyamide (PA6), with torsion protection, Ø 20 mm, vmax = 30 m/s (air)
without filter: NL = 202.5 mm / with plastic filter: NL = 235 mm (optional with metal filter: NL = 227 mm)
Electrical connection
0.14 - 1.5 mm², via push-in terminal
Cable connection
cable gland, plastic (M 16 x 1.5; with strain relief, exchangeable, max. inner diameter 10.4 mm) or
M12 connector according to DIN EN 61076-2-101 (optional on request)
Housing dimensions
126 x 90 x 50 mm (Tyr 2)
Cable gland
2x M 16 x 1.5; including strain relief, exchangeable
Long-term stability
< 2 % in 15 years
Protection class
III (according to EN 60 730)
Protection type
IP 65 (according to EN 60 529) housing only! (PLEUROFORM IP 30)
Protection type housing
IP 65