Development of a Portable and Sensitive CO2 Measurement Device with NDIR Sensor Clusters and Minimizing Water Vapor Impact

Abstract

Increasing carbon dioxide (CO2) concentrations threaten human production and life. Currently the equipment used for CO2 monitoring is heavy and expensive, without a portable CO2 detector that is inexpensive and resistant to interference. Here we designed a portable CO2 detector based on no-dispersive infrared sensors to measure CO2 concentration. The detector, which has a mass of 1 kg, is powered by a lithium battery with dimensions of 200 mm (length) × 150 mm (width) × 100 mm (height). Considering the fact that field observations are susceptible to humidity, a series of experiments were carried out to reduce the humidity interference on sensor responses at a laboratory. The values of humidity and CO2 variation were used in a regression model analysis to determine a quadratic function with an R2 above 0.94. The detector was compared with a reference analyzer in ambient CO2 measurement during a 7-day field campaign in Hangzhou, China. After humidity correction, the data show better correlation with the reference data, with the R2 0.62–0.97 increasing from 0.62–0.97 compared to before the correction and the value deviation decreasing to less than 3%. Cluster analysis of sensors revealed a reduction in average relative deviation of up to 1.4% as the number of sensors increased.

Index Air Quality Monitoring for Light and Active Mobility

“…By measuring the amount of absorbed light and comparing it with a known concentration, the CO 2 concentration in a gas sample can be assessed. This technology, known as transmissive NDIR (non-dispersive infrared), requires a minimum optical path length of several centimeters to ensure sufficient absorption of infrared rays at low CO 2 concentrations [23]. NDIR sensors have high accuracy (±30-200 ppm), wide measuring range (0-10,000 ppm), durability, reliability, slow response times (30-100 s), and high power consumption [3].…”

Research on pyroelectric enhancement mechanism of PZT thin films and optimization design of infrared detectors

“…Infrared detectors, as an important tool for human beings to perceive the spectrum of infrared wavelengths and transfer information, have been successfully applied in the fields of environmental monitoring [1][2][3], medical diagnostics [4,5], industrial process control [6] and others. Infrared detectors can be classified into two types based on their energy conversion method: thermal detectors and photon detectors [7].…”