Features of carbon dioxide detector from Dadzhet in comparison with AZ INSTRUMENTS 7798 CO2

When breathing, a person exhales a lot of carbon dioxide (CO2), and as you know, an overabundance 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 level of CO2. To ensure a comfortable level of CO2, it is necessary to regularly ventilate the room or install a forced ventilation system. But in order to understand when it is time to air or how much power to include ventilation, it is necessary to know the level of carbon dioxide concentration in the air. For this purpose, carbon dioxide level meters (CO2 detectors) are used.

Already talked about different CO2 meters

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





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Normal CO2 level

The level of carbon dioxide on the street is 400 ppm and practically does not depend on the location - on a gassed street in Moscow and in nature the level will be almost the same. It is believed that CO2 levels up to 700 ppm are practically imperceptible to humans, and levels up to 1000 ppm are acceptable. Anything higher already has a negative effect on the body.

Indication

The instrument alternately shows CO2 concentration (15 seconds) and temperature (5 seconds).







Three LEDs (green, yellow, red) show 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 exceeding

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). While the CO2 concentration remains exceeded, the device beeps once every seventeen minutes at the “yellow” level of the excess of the CO2 concentration and once a minute at the “red” level, reminding of the need to air the room.

Mute and Calibration

Behind the two buttons that select the display ranges, calibration modes, altitude and temperature measurement scale. A long press on the Enter button turns the sound on and off.







Micro USB connector on the right.







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

Without power supply

The power supply is not 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 once every four seconds, when it is measured, the consumption increases to 150 mA per fraction of a 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 from it.



The device is manufactured by ZyAura and differs from their model ZGm053U only by the presence of a sound signal. The device was built on the sensor ZG01C, produced by the same company. The technology to determine the level of CO2 best of all that is - Dual Beam NDIR.

Comparison

To check the accuracy of the measurement, I compared the readings of this device 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 the concentration of carbon dioxide over a long time. The program can be downloaded in the section "For the curious" 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

More - in the basement. You can clearly see how for three hours the CO2 level at a closed window and staying in one person’s 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 small 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 properly at least once a week, the room should be tested so well that the CO2 concentration in it is level with the outside one.



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



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



Author Alexey Nadyozhin (ammo1), Moscow