The GW-3000D infrared carbon monoxide sensor is developed based on long path multiple reflection cell and gas filter correlation (GFC) modulation technology. By comparing the absorption of sample gas and reference gas in the infrared band, the concentration of CO in the sample gas is measured according to Lambert Beer's law. The sensor integrates complete drift control and temperature control circuits internally. This instrument is suitable for automatic monitoring of ambient air quality, indoor air quality testing, industrial process analysis, and pollution source monitoring, and meets relevant national standards.
Measuring gasesCO2、CO
measurement range0-20ppm/0-2000ppm、0-50ppm/0-500ppm
Technical PrincipleNDIR
Application fieldAir quality testing; Pollution source monitoring; Industrial process gas analysis and other occasions
Carbon monoxide sensorProduct Features
Adopting infrared wavelength filtering technology (GFC) and long path gas absorption cell (L-Cell), it has the ability to detect ultra-low gas concentration and differential signal working mode, with strong anti-interference ability. Imported DC steady-state light source, with an extremely long service life, reduces maintenance troubles. Internally, a self-tuning PID algorithm is used for high-precision temperature control. Each component adopts modular design, with high reliability, good scalability, and easy maintenance. It uses high-performance refrigeration type photoelectric detectors, which have faster response rate and better signal-to-noise ratio compared to pyroelectric detectors. The type and range of the gas to be tested can be customized according to requirements.
Technical principle:
1- Technical principles
Principle of Long Path Absorption
According to Lambert Beer's absorption law, the intensity of gas absorption can be changed by extending the length of light flow. We adopted a structure with multiple reflection cells, achieving optical path lengths several times or even tens of times the physical size, to achieve higher detection sensitivity and lower gas detection limits.
2-Optical Structure
The infrared light emitted by the GFC optical structure light source alternately enters the gas chamber through the GFC modulation wheel. One path is absorbed by the gas chamber filled with CO, and the other path passes through the gas chamber without CO. The two paths of light are converged by lenses and received by the detector. After processing, the absorption signal and reference signal are obtained. This structure can offset some of the effects of water vapor and external circuit or temperature noise, providing product stability.
3- Absorption spectrum
The absorption spectrum sensor for carbon monoxide analyzes component concentrations by detecting the absorbance spectrum near the absorption peak of carbon monoxide at 4.65um. In order to avoid the absorption of CO by other gases, we chose a narrower absorption peak for optical design. Finally, the effect of negligible interference from high concentration gases such as CO2 and CH4 on CO detection was achieved.
4- Long term drift
After 30 days and 24 hours of drift tracking measurement, the stability of the sensor's long-term measurement was investigated, and the long-term stability data of the CO sensor at zero and 80% range concentration were obtained. The sensor chamber maintains a constant temperature of 40 ℃ for measurement at room temperature
5- Repeatability
Operate under the same standard gas and conditions, and complete repeated experimental tasks in the shortest possible time interval. Introduce nitrogen and 80% range gas in sequence, repeat the operation 6 times for repeatability experiment; According to the experimental curve, it can be seen that the maximum zero point is between 1 and 5, with a deviation of 5ppm.
Application scenarios
This instrument is suitable for automatic monitoring of ambient air quality, indoor air quality testing, industrial process analysis, pollution source monitoring and other fields, and complies with relevant national standards. Sensors have the characteristics of high accuracy, small drift, and low cross interference.The product is mainly used in the following situations:
● Air quality testing;
● Pollution source monitoring;
Industrial process gas analysis and other occasions.
Carbon monoxide sensorTechnical Indicators:
Measuring principle |
Infrared absorption (NDIR) |
measurement range |
CO：0-50ppm/0-500ppm
CO2：0-20ppm/0-2000ppm
|
Sample gas flow rate |
0.8L/min±10％ |
response time |
≤28s |
indication error |
≤±2%F.S. |
drift |
≤±2%F.S. |
repetitiveness |
1% |
warm-up time |
≤20min |
output interface |
RS232 (default) RS485、（4～20）mA |
*The specific range may have slight deviations | Working at a temperature of 25 ℃ and 1013 mThere may be slight deviations in the specific range | Operating at 25 ℃ and 1013 mbar test data
