1）  CHARACTERISTICS OF CARBON DIOXIDE AND APPLICATIONS OF ITS SENSOR

Our earth is surrounded by a layer of atmosphere, of which oxygen accounts for about21％，78% is nitrogen,1% are other gases. This1% of the gas, there is a small part of carbon dioxide gas, about350—450ppm(one in a million, namely0.035％—0.045%), it is heavier than air1.5Times; can absorb infrared waves, resulting in the greenhouse effect. 

The higher the content of carbon dioxide in the air, the greater the impact on the human body.0.7%, the human body will feel uncomfortable;10%, the body will appear coma or death;20The person will die in a few seconds. Therefore, in crowded places, carbon dioxide content is a very important parameter, which is directly related to the comfort and safety of the human body.

At the same time, it is also an important element of photosynthesis in plants. It can also be said that without carbon dioxide, there is no vitality in nature. Because of this, carbon dioxide is a necessary parameter when doing plant experiments.

in the chemical industryAfter chemical reactions, many high concentrations of carbon dioxide gas will be produced, and in beer, cola and other beverages, carbon dioxide must be added; mixing carbon dioxide and nitrogen into an "ideal" gas, acting on the inflatable packaging of fresh food, It can maintain the activity of the cells inside the fresh food for a certain period of time, delay its life process, and maintain a certain degree of fresh state. Therefore, due to these characteristics of carbon dioxide gas, such as airports, buildings, offices, factories and mines, greenhouses, laboratories,Chemical, food preservation and other industries will need to measure the value of carbon dioxide.

2) CO2 parameters inHVACImportance and Application 

First introduceHVAC：HVACrepresents heating, ventilation and air conditioning, whileIAQRepresents indoor air quality. In order to keep energy losses low, almost closed heating and air conditioning systems are used. According to the number of people in the room or due to other activities (such as cooking with gas), the air quality decreases, which can be measuredCO2level to check.

The accumulation of pollutants is often associated with a lack of proper ventilation, and these pollutants can have dangerous effects on building occupants, vehicles, and people in other enclosed areas. Proper ventilation is not only important for the comfort of personnel, but also for the economic operation of heating and air conditioning systems.

United StatesOSHA (Occupational Safety and Health Administration), yes.CO2ListSTEL(short-term maximum exposure limit,15Minutes) 30，000ppmandTWA (Time-weighted average exposure limit,8 Hours)  5，000 ppmof standards.OSHAIn1995There are some suggestions for indoor air quality rules in, ifCO2The level exceeds800 ppmA fresh air supply is required.
 

Therefore,CO2InHVACis a very important parameter. And indoorCO2There is a close relationship between the concentration and ventilation. Whether it is in a space, with more or less people, this system can effectively save valuable energy and maintain good indoor air quality.

Generally speaking, InstallCO2The benefits of a control-based ventilation control system are apparent, and the investment in equipment can be repaid by the energy savings within two years.CO2In building ventilation control, sensors are widely used in airports, office buildings, shopping centers, training centers, hospitals, factory workshops, subways, cinemas and other high-level places where people gather for entertainment and activities.

3) United KingdomGSSBackground of the birth of ultra-low power carbon dioxide sensor

The market demand for ventilation control based on carbon dioxide sensors is taking place, and the growing market demand is due to the advantages of energy efficiency: with proper ventilation control, up25%energy-saving buildings, while promoting the comfort of indoor staff, improve work efficiency.

GSSAnd Schneider Electric Innovation has been in deep cooperation to jointly develop this ultra-low power consumption for the construction and residential markets.NUMBERCarbon dioxide sensor. This carbon dioxide sensor has good low power consumption and performance, which opens the way for a high-precision carbon dioxide monitoring solution that can be compatible with long-life batteries or solar cell powered devices. Due to its simple, cost-effective installation and flexibility, this innovative wireless battery-powered integrated CO2, temperature and humidity sensor provides an ideal solution to meet the building HVAC control market.