CO2 - Gas Sensor Module

The module CO2-4K-3M-P is designed to measure the
concentration of Carbon-dioxide in the air. This concentration is an
reliable indicator for the “quality” of the air in e.g. a conference
room. The higher the concentration of CO2 the worse is the quality
of the air. High values of CO2 concentration in the air make a
person tired and the mental performace will decrease. In “fresh
air” the concentration of CO2 is 0.034% (vol) which corresponds
to 340 ppm. The indoor concentration in offices should not exceed
1000 ppm, and the maximum allowable concentration is 5000 ppm.
The CO2 module CO2-4K-3M-P is based on an optical mesurement
principle. infrared radiation of wavelength 15 μm is emitted
from a light source and is detected by a wavelength selective
detector. Depending on the length of the optical path and the
concentration of CO2 the light is absorbed (and re-emitted in all
directions).
Measurement range is 400 ppm ... 4000 ppm with a resolution
of 20ppm. The response time is about 180 seconds and there is
no pump necessary to drive the module. Output format is PWM.

Features

• Size of PCB (LxWxH): 65mm x 20mm x 9mm max.
• General / Electrical Characteristics:

- Output: PWM, OpenCollector to GND max. 5 mA

- Operating temperature: + 5 °C ... + 30° C

- Operating humidity: 20 % ... 100 % non-condensing

- Supply voltage: 5 VDC, ± 0.5 VDC

- Current consumption: 80 mA (ave.), < 150 mA (peak)

• CO2 - Measurement:

- Type of measurement: NDIR

- Measurement range: 400 ppm ... 4000 ppm CO2 - Measurement

- Resolution: < 20ppm CO2

- Response time (90%): < 180 sec.

- Warm-up time: < 30 sec. operational, < 15 sec. full accuracy

• PWM-Output Cycle:

- Cycle period: 1004 ms ± 5%

- Cycle start high level: 2 ms (nominal)

- Cycle end low level: 2ms (nominal)

Applications

• public buildings
• offices
• vehicles