Technical overview of NDIR CO2 sensor

CO2 sensor as an indicator of social distance

With the recent corona virus COVID-19, social distance is said to be important.

In other words, it is necessary to keep a certain distance between people.

It is believed that this new habit will continue.

What this means is that you need to prevent a virus infection before you get it.

What are the promising indicators for sensing technology that utilizes IoT in the event of a corona virus?

Nowadays, CO2 concentration measurement using CO2 sensor is attracting attention.

By breathing, a person inhales oxygen and exhales carbon dioxide.

In other words, the CO2 concentration can be used as an index to measure whether or not people are crowded.

Here, we would like to explain the utilization of the Sensor I / F LSI under development at Tele-Sentient when constructing a CO2 sensor.

CO2 sensor technology (NDIR method)

NDIR (Non Dispersive InfraRed) method is a commonly used method for CO2 sensors.

NDIR method is called the non-dispersive infrared absorption method.

Gas absorbs a specific wavelength due to its molecular structure.

By measuring the degree of absorption and analyzing the spectrum of infrared radiation absorption, the gas concentration can be measured.

In the case of CO2, it absorbs infrared rays in the vicinity of 4260 nm, so the CO2 concentration can be measured by shining light at 4260 nm from a light source and measuring the degree of absorption with a photodiode.

In addition, an analog technology such as an amplifier circuit for minute signals called AFE (Analog Front End) is required.

In principle, a CO2 sensor can be configured with a light source, photodiode, and AFE with the configuration shown above.

Tele-Sentient Sensor I/F LSI

The Sensor I / F LSI under development at Tele-Sentient includes a circuit to control the light source, a circuit to detect the signal of the photodiode, and an AFE circuit.

In other words, by connecting LEDs and photodiodes, you can configure a CO2 sensor.

The typical advantage of being made to order is that it supports Ultra Low Power Mode to reduce power consumption.

We would like to explain the details of Sensor I/F LSI and these advantages separately.

Tele-Sentient is looking for manufacturing partners and development partners.

If you are interested, please contact us from the following.