Introduction to Product Application

When it comes to air quality, it's easy to focus on PM2.5, but excess carbon dioxide is also a hidden killer. This statement may surprise many consumers. Isn't carbon dioxide non-toxic? How could it be a gas stealth killer?

1. Carbon dioxide is embedded in the air

It starts with carbon dioxide. As we all know, the content of oxygen and carbon dioxide in the atmosphere is relatively stable, with oxygen accounting for 21% and carbon dioxide accounting for 0.03%. Carbon dioxide itself is not toxic, but when the amount of carbon dioxide in the air exceeds normal levels, it can affect human health.

So why does carbon dioxide have too much oxygen? Because when you breathe, you take in oxygen and breathe out carbon dioxide. With more carbon dioxide, there is less oxygen in the air, and people are used to oxygen in their environment. When the amount of oxygen absorption is insufficient, it will naturally lead to people's maladaptation, resulting in people breathing is not smooth and other symptoms of hypoxia.

At present, the existing indoor air quality standards at home and abroad without exception include carbon dioxide as a key pollutant under control, and its content has long become an important index to evaluate the quality of indoor air.

2. Don't underestimate lack of oxygen

We all experience hypoxia in general. Shortness of breath, weakness of limbs, lethargy, lack of concentration, etc. When this happens, indoor carbon dioxide levels have risen to between 1000 and 5000 ppm. Such a concentration range, although not life-threatening, is also harmful to health. Severe hypoxia is even scarier, as it can cause brain damage, coma and even death when CO2 levels are above 5,000 PPM for a prolonged period of time.

Crowded classrooms, crowded meeting rooms, bedrooms, and cars all tend to cause high levels of carbon dioxide. Take the bedroom as an example. If two people sleep for 8 hours a night, the carbon dioxide concentration can rise to 4000ppm in one night without breathing. In a closed classroom for 60 minutes, the carbon dioxide concentration can reach 3000ppm, twice the current standard of 1500ppm in primary and secondary schools. However, in a car with tight Windows, the carbon dioxide concentration is often above 3000ppm and keeps climbing.



Don't underestimate this general lack of oxygen. It is enough to affect the working efficiency of the human brain, studies have shown that when carbon dioxide in 600ppm-4800ppm, the higher the concentration of carbon dioxide in the air, the lower the learning and work efficiency, the higher the operation error rate.



3. What is the solution

The concentration of carbon dioxide in the outdoor air in cities is usually between 400 and 500ppm. Through indoor air quality standards, we found that the comfortable and good indoor environment, the concentration of carbon dioxide is better controlled under 600ppm, which is almost the same as the outdoor carbon dioxide value. Therefore, the main way to crack the problem of hypoxia is to ventilation and outdoor ventilation, the introduction of fresh air. In the fresh air system, a very important component is the carbon dioxide sensor. The carbon dioxide sensor can monitor indoor carbon dioxide concentration in real time online, and adjust the opening of the fresh air system and the power air supply volume according to the concentration value.



How to choose a suitable CO2 sensor is very important. Here, Shenzhen Wiao Instrument Co., Ltd. recommends the use of CO2 sensor CDM7160 imported from Japan. The sensor adopts single light source and dual wavelength mode, which has the advantages of high precision, stable long-term performance, long life and small size.

Main parameters of CDM7160:

Power supply: 5.0±0.25V

DC working principle: Nondispersive infrared Absorption (NDIR)

Detection range: 300-5000ppm

Operating temperature: 0-50℃

Operating humidity: 0-85%RH

Output features: UART/IIC interface

Life span: >5 years

Accuracy: ±50ppm+3%

Power consumption: 10mA (average)

CDM7160 is usually used in high-speed railway stations, subway stations, airports, hospitals, libraries and other public places with dense population for a long time. It can also be used in indoor air quality control systems such as BEMS and HEMS.