Everything for Electronics
Posted in: Nuts and Volts (June 2012)

Do you ventilate sufficiently?

A fresh air contains approximately 400 ppm of CO2 and in an average room a concentration of CO2 reaches a double value already within an hour. This is valid at residing of 1 person in rest. If there are more people in a room, who moreover do some physical activity, then to keep an air quality it is necessary to exchange an air volume in a room even a few times per hour. 1000 ppm is considered to be a maximum acceptable value for a long-term residing, while 700 ppm is a limit for a fresh air feeling. At higher concentrations, a lassitude and sleepiness appears and a high CO2 concentration can lead to chronical difficulties. From the above-mentioned example, it´s easy to imagine how quickly can be the air unhealthy, for example in a poorly ventilated office. Naturally, the biggest enemy of a sufficient ventilation is increasing of expenses for heating and air conditioning.

Advantages / Features:

  •     pre-calibrated module for measuring of CO2 concentration
  •     easy application
  •     long lifetime
  •     400-4000 ppm range suitable for air quality measuring
  •     linear output in a 0.4-4V range
  •     low power consumption - 300mW


The ready-made module Figaro CDM4161a is very suitable for monitoring of indoor CO2 concentrations. It is able to measure the CO2 concentration in a 400-4000 ppm range, what responds to an output voltage of 0.4 to 4 V. At the same time, the module has a „Control“ output, which changes its status to High after exceeding of 1000 ppm and it is suitable for example for a direct ventilation control. CDM4161a is maintenance free, pre-calibrated from production, but it also has a possibility of „recalibration“ – after applying a High level on the Reset input (setting of 400 ppm).

CDM4161a can be used for ventilation control, but even for a visual inspection – in conjunction with an indicator or similar. At the end, such a solution brings savings of expenses for energies (heating/ air conditioning) and mainly it increases the indoor air quality.

Detailed information will provide you the CDM4161a and TGS4161. First pieces are already on stock, in case of interest, please contact us at [email protected].


[Source] SOSElectronic