MNS-QT221 NDIR CO2 Gas Sensor
Product Description
MNS-QT221 NDIR CO2 Gas Sensor Overview
The MANORSHI MNS-QT221 is a compact NDIR CO2 gas sensor designed for reliable carbon dioxide concentration measurement in industrial, environmental, HVAC, agricultural, and OEM monitoring equipment. Using Non-Dispersive Infrared (NDIR) technology, the sensor detects CO2 through its characteristic infrared absorption, providing stable performance, good selectivity, and long service life.
The MNS-QT221 supports multiple CO2 measurement ranges, including 0–2000 ppm, 0–5000 ppm, 0–1% vol, 0–2% vol, 0–5% vol, and 0–100% vol. These range options make the sensor suitable for both low-concentration air quality monitoring and high-concentration industrial CO2 detection.
With a 3.3–5 VDC operating voltage, UART digital communication, and 0.4–2 V analog output, the MNS-QT221 can be easily integrated into gas detectors, embedded systems, ventilation controllers, and other CO2 monitoring devices.
How Does the MNS-QT221 NDIR CO2 Sensor Work?
The MNS-QT221 uses NDIR infrared absorption technology to measure carbon dioxide concentration. An infrared light source sends infrared energy through the gas sample chamber. CO2 molecules absorb infrared energy at specific wavelengths, and the infrared detector measures the change in received light intensity.
The sensor then converts the infrared absorption signal into a CO2 concentration value and outputs the measurement through UART or analog voltage. Because the sensing principle is based on optical absorption rather than chemical reaction, NDIR CO2 sensors offer good long-term stability, resistance to poisoning, and reliable performance in continuous monitoring applications.
Key Features of the MNS-QT221 CO2 Gas Sensor
NDIR infrared technology for reliable CO2 measurement
Multiple measurement ranges from 0–2000 ppm up to 0–100% vol
Measurement accuracy of ±5% FS
Operating voltage: 3.3–5 VDC
UART digital communication interface
0.4–2 V analog voltage output
Built-in temperature compensation
Fast response time: T90 <30 seconds
Average current consumption: <85 mA
Operating temperature: -20°C to +60°C
Operating humidity: 0–95% RH, non-condensing
IP65 protection level
Service life of more than 5 years
Good resistance to water vapor interference
High sensitivity and high resolution
Compact design for OEM integration
Technical Specifications
Product Model: MNS-QT221
Target Gas: Carbon Dioxide (CO2)
Detection Technology: NDIR Infrared Absorption
Measurement Ranges: 0–2000 ppm, 0–5000 ppm, 0–1% vol, 0–2% vol, 0–5% vol, 0–100% vol
Accuracy: ±5% FS
Operating Voltage: 3.3–5 VDC
Average Current: <85 mA
Interface Level: DC 3.0 V
Output Signal: UART and 0.4–2 V analog voltage
Warm-Up Time: 180 seconds
Response Time: T90 <30 seconds
Operating Temperature: -20°C to +60°C
Operating Humidity: 0–95% RH, non-condensing
Protection Level: IP65
Expected Lifespan: More than 5 years
Weight: 25 g
UART and Analog Output for Easy System Integration
The MNS-QT221 CO2 sensor provides both UART digital communication and analog voltage output, offering flexible integration for different control and monitoring systems.
The UART interface can be connected to microcontrollers, embedded systems, and digital control boards, while the 0.4–2 V analog output can be used with compatible analog acquisition circuits.
The five-pin interface includes GND, voltage input, UART RXD, analog Vout, and UART TXD connections. This interface configuration helps simplify installation in OEM gas detection products and compact monitoring equipment.
Temperature Compensation for Stable CO2 Measurement
Temperature changes can affect gas sensor measurement performance. The MNS-QT221 includes built-in temperature compensation to help maintain stable CO2 readings across its operating temperature range of -20°C to +60°C.
The sensor also provides good resistance to water vapor interference. Combined with NDIR optical sensing technology, this makes the MNS-QT221 suitable for long-term and continuous carbon dioxide monitoring.
Multiple CO2 Measurement Ranges
The MNS-QT221 is available with several measurement range options to support different applications.
For indoor air quality and ventilation monitoring, lower concentration ranges such as 0–2000 ppm and 0–5000 ppm are suitable.
For industrial gas monitoring and process applications, higher ranges such as 0–1% vol, 0–2% vol, 0–5% vol, and 0–100% vol can be selected according to the required CO2 concentration level.
This range flexibility allows equipment manufacturers to use the same sensor platform across different CO2 monitoring products.
Typical Applications
The MNS-QT221 NDIR CO2 gas sensor can be used in a wide range of carbon dioxide monitoring and control applications, including:
Indoor air quality monitoring systems
CO2 gas detectors
HVAC systems
Ventilation control equipment
Industrial gas monitoring systems
Environmental monitoring instruments
Greenhouse CO2 monitoring
Agricultural equipment
Smart building systems
Gas concentration monitoring equipment
Safety monitoring devices
OEM gas sensing products
Embedded CO2 monitoring systems
Why Choose the MANORSHI MNS-QT221 CO2 Sensor?
The MANORSHI MNS-QT221 combines NDIR CO2 detection technology, multiple measurement ranges, UART communication, analog output, temperature compensation, and compact construction in one sensor.
Its multiple concentration ranges make it suitable for both ppm-level air quality monitoring and high-concentration CO2 measurement.
With a response time of T90 <30 seconds, IP65 protection, and an expected service life of more than five years, the MNS-QT221 is designed for applications that require reliable, stable, and long-term carbon dioxide monitoring.
For equipment manufacturers and OEM customers, the MNS-QT221 provides a practical CO2 sensing solution with flexible output options and convenient system integration.
Frequently Asked Questions
What type of CO2 sensor is the MNS-QT221?
The MNS-QT221 is an NDIR carbon dioxide sensor. It measures CO2 concentration using infrared absorption technology.
What CO2 measurement ranges are available?
Available measurement ranges include 0–2000 ppm, 0–5000 ppm, 0–1% vol, 0–2% vol, 0–5% vol, and 0–100% vol.
What output interfaces does the MNS-QT221 provide?
The sensor supports UART digital communication and a 0.4–2 V analog voltage output.
What is the operating voltage?
The MNS-QT221 operates from a 3.3–5 VDC power supply.
What is the response time?
The specified response time is T90 <30 seconds.
Does the MNS-QT221 include temperature compensation?
Yes. The sensor includes temperature compensation to improve measurement stability under changing environmental temperatures.
What is the operating temperature range?
The operating temperature range is -20°C to +60°C.
What is the protection level?
The MNS-QT221 has an IP65 protection level.
What is the expected service life?
The expected service life is more than five years under suitable operating conditions.
Is the MNS-QT221 suitable for OEM products?
Yes. Its compact design, multiple CO2 measurement ranges, UART interface, analog output, and long service life make it suitable for integration into OEM gas detection and monitoring equipment.