Features of the carbon dioxide detector from Dadget in comparison with AZ INSTRUMENTS 7798 CO2 / Dadget Blog

When breathing, a person exhales a lot of carbon dioxide (CO2), and as you know, an excess of it in the air can cause many problems with well-being and chronic fatigue syndrome. In almost all urban apartments, ventilation is not sufficient to maintain a comfortable CO2 level. To ensure a comfortable CO2 level, it is necessary to regularly ventilate the room or install a ventilation system. But in order to understand when it is time to ventilate or at what capacity to turn on ventilation, you need to know the level of carbon dioxide concentration in the air. For this, carbon dioxide level meters (CO2 detectors) are used.

Already talked about various CO2 meters

Now - a new version of this device, but with an audible alarm and new software.

Normal CO2

The level of carbon dioxide on the street is 400 ppm and is almost independent of location - on the gassed street of Moscow and in nature the level will be almost the same. It is believed that CO2 levels of up to 700 ppm are almost invisible to humans, and levels of up to 1000 ppm are acceptable. Everything above is already negatively affecting the body.

Indication

The instrument alternately displays the concentration of CO2 (15 seconds) and temperature (5 seconds).



Three LEDs (green, yellow, red) indicate the level of comfort in terms of carbon dioxide concentration. By default, green is up to 800 ppm, yellow is 800-1200 ppm, red is more than 1200 ppm. If desired, these ranges can be changed.

Threshold exceeded

When the sound is turned on, the device beeps once when the first threshold is exceeded (800 ppm by default) and three times when the second threshold is exceeded (1200 ppm by default). As long as the CO2 concentration remains exceeded, the appliance beeps once every seventeen minutes with a “yellow” level of excess CO2 concentration and once a minute with a “red” level, reminding you to ventilate the room.

Mute and calibration

There are two buttons on the back with which you can select the display ranges, calibration modes, altitude and temperature scale. A long press of the Enter button turns the sound on and off.



Micro-USB connector on the right.



The device is equipped with a USB-Micro-USB cable, one and a half meters long.

Without power supply

No power source included. The device can be connected to any charger with a USB connector. I measured the consumption of the device. It constantly consumes 22 mA, and every four seconds, when it is measured, the consumption increases to 150 mA for a split second. For an hour, the device consumes 31 mAh, which means that it can be used independently with any Power Bank and it will work for a very long time.

The device is manufactured by ZyAura and differs from their model ZGm053U only in the presence of an audio signal. The device is built on the ZG01C sensor manufactured by the same company. The technology for determining the level of CO2 is the best of all that is - Dual Beam NDIR.

Comparison

To check the accuracy of the measurement, I compared the readings of this instrument with the AZ INSTRUMENTS 7798 CO2 datalogger . The CO2 detector described in this article turned out to be very accurate - the readings are almost identical.

PC connection

The device can be connected to a computer and build graphs of changes in carbon dioxide concentration over a long time. The program can be downloaded in the "For the Curious" section of the page .

When connected to a computer, the device is recognized as a standard input device. The program does not require installation and configuration. It shows changes in CO2 level and temperature over the last hour or over a long period.

Screen shots

Also in the basement. You can clearly see how in three hours the level of CO2 with a closed window and when one person is in the room increases from 600 to 1000 ppm, and then after opening the balcony door it drops to 600 ppm in ten minutes.

Video

I shot a short video to show how the device works and what sound signals it emits.



https://youtu.be/F4n8ghxXPMo

By default, the device calibrates the sensor once a week, so for it to work correctly at least once a week, the room should be checked so that the CO2 concentration in it is aligned with the street.

So far, these devices are not very common (primarily because of the high cost of the sensor), but I'm sure that a CO2 level meter must be in every apartment, and even better in every room. I have been using the CO2 meter constantly for two and a half years and have presented these detectors to my friends and relatives for three.

I believe that the CO2 meter is one of the best and most useful gifts for the upcoming holidays.

Author Alexey Nadezhin (ammo1), Moscow