CO2 Sensors: Different types of carbon dioxide Sensors

User：JXCTUpload time：Sep 16 2022

INGENUITY

What is a CO2 Sensor?

CO2 Sensor is a gas detection instrument, mainly used to measure the content of carbon dioxide in the air. When the carbon dioxide content is too much or too little, the carbon dioxide sensor will give an alarm, people will take corresponding measures according to its prompt. The air quality meets people’s requirements. This device is mainly used in daily production and life, and plays an important role in creating a good atmospheric environment for people. Carbon dioxide sensors are not used in a wide range of applications, including the beer industry, carbonated drinks industry, coal industry, agricultural farming industry, agricultural aquaculture industry and People’s Daily life.

Type of carbon dioxide sensor

There are many types of carbon dioxide sensors on the market. In order to be able to correctly choose the most suitable sensor for you, below JXCT lists four common types of carbon dioxide sensors on the market according to how they work.

*Non-dispersive infrared carbon dioxide sensor
*Electrochemical carbon dioxide sensor
*Semiconductor carbon dioxide sensor
*Catalytic combustion carbon dioxide sensor

1.Non-dispersive infrared carbon dioxide sensor

The non-dispersive infrared carbon dioxide sensor is made according to the working principle that the absorption spectrum of gas varies with different substances. The carbon dioxide sensor controls the internal infrared lamp to emit infrared light of fixed band by driving circuit. After the measured gas is absorbed, the amplitude of infrared light changes, and then the concentration of the measured gas is calculated by detecting the change, that is, the signal output of the sensing element is filtered, amplified, collected and converted by ADC, and then input to the microprocessor.

Advantages: High sensitivity, fast analysis speed, good stability, long service life.
Disadvantages: The NDIR sensor has large power consumption, complex structure, complex hardware and software, and relatively expensive price.

2.Electrochemical carbon dioxide sensor

Electrochemical carbon dioxide sensor is a chemical sensor that converts the concentration of carbon dioxide (or partial pressure) into an electrical signal through an electrochemical reaction. According to the detected electrical signal, the electrochemical type is divided into potential type, current type and capacitance type. According to the electrolyte form is divided into liquid electrolyte and solid electrolyte. Since 1970s, solid electrolyte carbon dioxide sensor has been the focus of scientific research workers. The principle of solid electrolyte carbon dioxide sensor is that the gas sensitive material generates ions when passing through the gas, thus forming the electromotive force, and the volume fraction of the gas is measured by measuring the electromotive force.

Advantages: Fast measuring speed, simple operation, low cost.
Disadvantages: Short life, easy to age, sensor easy to “drift” or lose accuracy. The measurement accuracy is easily disturbed by other gases.

3.Semiconductor carbon dioxide sensor

The semiconductor gas sensor is made of gas REDOX reaction on the semiconductor surface to change the resistance value of the sensitive element. When the semiconductor device is heated to a stable state, when the gas contact the semiconductor surface and is adsorbed, the adsorbed molecules first diffuse freely on the surface of the object and lose their motion energy. Some of the molecules are evaporated, and some of the remaining molecules are thermally broken down and attached to the object. On the surface. When the work function of the semiconductor is less than the affinity of the adsorbed molecule, the adsorbed molecule will steal electrons from the device and become adsorbed negative ions, and the surface of the semiconductor presents a charge layer. If the work function of the semiconductor is greater than the dissociation energy of the adsorbed molecule, the adsorbed molecule will release electrons to the device and form positive ion adsorption. It is a gas sensor made of the change of capacitance voltage characteristic of MOS diode and the change of threshold voltage of MOS field effect tube.

Advantages: Fast response, strong environmental resistance, stable structure
Disadvantages: susceptible to temperature and humidity, usually used for higher and less common CO2 concentrations, other substances in the air can affect readings

4.Catalytic combustion carbon dioxide sensor

Catalyst carbon dioxide sensor is a carbon dioxide sensor based on catalyst. It uses a catalyst coating on the surface of a specific type of resistor. The principle of catalytic combustion of combustible gas on the surface as a carbon dioxide sensor at a certain temperature. Therefore, people call this kind of carbon dioxide sensor thermal combustion sensor.

Advantages: accurate measurement, fast response, long life.
Disadvantages: Small gas range to choose from.

Top4 CO2 Sensor

Portable CO2 Gas Detector

Portable CO2 detector, waterproof, dustproof, accurate detection data, sound and light alarm, long service life. The portable CO2 detector can be used in indoor air detection, gas leakage, pharmaceutical factories and other scenes.Portable CO2 detector, waterproof, dustproof, accurate detection data, sound and light alarm, long service life. The portable CO2 detector can be used in indoor air detection, gas leakage, pharmaceutical factories and other scenes.When the detected gas is more than the set gas value, the sensor will turn on the light alarm and the high-decibel buzzer will beep.
The instrument is marked red to remind in time, and the safety is high.

Stationary carbon dioxide gas detector

Fixed gas detector, stable performance, sensitive and reliable. With high precision liquid crystal display, explosion-proof enclosure, spread or pump suction. CO2 gas detector has the characteristics of flexible use and simple operation. CO2 gas detector is suitable for all kinds of gas leakage places, such as: city gas, petroleum, chemical, pharmaceutical, steel, special industrial plant and other fields. The explosion-proof grade of CO2 gas detector is CT6.

NDIR CO2 gas sensor

The carbon monoxide CO2 detection module is a gas sensor module that adopts the NDIR infrared absorption detection principle introduced by instrument manufacturers such as analyzers. The concentration is determined based on the absorption of infrared gases by the gas. JXCT CO2 sensor adopts imported light source, special structure of optical cavity and dual channel detector to realize space dual optical path reference compensation. UART, 485 output, analog current/voltage output, to facilitate customer use in a variety of application environments

Electrochemical gas sensor

Carbon dioxide electrochemical gas detection sensor, the three electrode structure design, the built-in high precision electrochemical sensor, gas concentration by the internal amplifier circuit signal output to the customer need the precise digital signal, noise processing, temperature compensation, each sensor before delivery through standard calibration gas processing, is a mature and excellent electrochemical detection circuit design, The generality ensures that the receiving sensor module directly outputs usable and accurate gas concentration information

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