Multifunctional on-wall sensors and measuring transducers, for CO2 content and air quality (VOC) AERASGARD® ALQ-CO2-W

Display

Product group: WG02

Maintenance-free AERASGARD® ALQ - CO2 - W air quality on-wall measuring transducer with active/switching output, automatic calibration (can be deactivated), in an impact resistant plastic housing with quick-locking screws, optionally with/without display, for determining the CO2 content of the air (0...2000 ppm/0...5000 ppm), the air quality in three VOC sensitivity levels (low/ medium/high) as well as temperature (–35...+80 °C) and relative air humidity (0…100% r.H.). The transmitter converts the measured values into a standard signal of 0-10 V or 4...20 mA (switchable).

It 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.

A long-term stable, digital humidity and temperature sensor guarantees precise measuring results.

CO2 measuring is performed using an optical NDIR sensor (non-dispersive infra-red technology). The detection range is calibrated for standard applications such as the monitoring of residential and conference rooms.

Air quality is detected by a VOC sensor (mixed gas sensor for volatile organic substances). This sensor determines the load of contaminated gases in the room air, such as from cigarette smoke, body perspiration, exhaled breathing air, solvent vapours, emissions from building components, etc. Low, medium or high VOC sensitivity can be selected depending on the expected air contamination.

Available configurations

Artikelnummer	Bezeichung
1501-7111-7301-500	AERASGARD® ALQ-CO2-W
1501-7111-7371-500	AERASGARD® ALQ-CO2-W LCD

Voltage supply

24 V AC/ DC (± 10 %)

Power consumption

< 4.8 W/ 24 V DC typical; < 6.8 VA/ 24 V AC typical; peak current 200 mA

Data points

Air quality (VOC), carbon dioxide (CO2)

Sensor, VOC

VOC sensor (metal oxide) (VOC = volatile organic compounds),
with manual calibration (via zero button),
with automatic calibration (can be deactivated via DIP switches)

Measuring range, VOC

0...100 % air quality; referred to calibrating gas;
multi-range switching (selectable via DIP switches)
VOC sensitivity low, medium, high

Output, VOC

0 -10 V (0 V = clean air, 10 V = polluted air) or 4...20 mA (selectable via DIP switches,
switchpoint can be adjusted from 0...100 % of the output signal)

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

multi-range switching (selectable via DIP switches)
0...2000 ppm; 0...5000 ppm

Sensor, CO2

Optical NDIR sensor (non-dispersive infra-red technology),
with manual calibration (via zero button),
with automatic calibration (can be deactivated via DIP switches)

Output, CO2

0 -10 V or 4...20 mA (selectable via DIP switches)

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

Relay output

with potential-free changeover contact (24 V / 1 A)
(assignment selectable via DIP switches, switchpoint adjustable)

Response time

< 2 minutes

Output

0 -10 V or 4...20 mA, working resistance < 800 Ω
(selectable via DIP switches, selected variant applies for all outputs),
with offset potentiometer (± 10 % of the measuring range)

Measuring range

0...100 % Air quality - VOC sensitivities (low/medium/high)

Measuring ranges

0...100 % Air quality - VOC sensitivities (low/medium/high)
0...2000 ppm / 0...5000 ppm

Ambient temperature

–10...+60 °C

Process connection

by screws

Protective tube

stainless steel V2A (1.4301), Ø 16 mm, NL = 55 mm

Electrical connection

0.14 - 1.5 mm² via terminal screws