Sensitivity Correction and Reliability of Carbon Dioxide Detector
The carbon dioxide detector is composed of a single-chip microcomputer MSP430 and a new gas sensor. The low-power non-heating semiconductor gas sensor is selected to collect the carbon dioxide concentration and convert it into an electrical signal, and then the corresponding data is processed by MSP430, and the sensitivity of the instrument is corrected by software to improve the reliability of the carbon dioxide detector.
The carbon dioxide detector software adopts functional modular design, which consists of a main program and 4 subroutine modules. The main program completes the initialization, system self-test and sub-module call; the data acquisition and A/D conversion sub-module automatically completes the signal acquisition and enters the MSP430A/D port, and the data processing sub-program completes the processing of the data collected by the A/D port ( Including the processing of voltage and frequency parameters); the liquid crystal display sub-module completes the software drive and concentration display of the liquid crystal module; the interrupt sub-module completes the processing of various interrupt signals, such as the interrupt signal generated by the CO2 concentration exceeding the standard to drive the motor to work, etc.
Sensitivity correction
The carbon dioxide detector converts the carbon dioxide concentration into an electrical signal through a sensor. During the measurement process, the sensitivity of the sensor will decrease with the increase of the use time and the instability of the power supply voltage of the instrument, which will affect the measurement accuracy, so it must be corrected for sensitivity. Due to the many interference signals received by the carbon dioxide detector, if the hardware circuit compensation is used, new interference will inevitably be introduced. Considering comprehensively, a software method is used to correct the sensitivity.
The carbon dioxide detector uses MSP430 with low power consumption and on-chip peripherals as the main control chip to detect the concentration of carbon dioxide, so that the instrument has LCD display and drive motor output mode, which can automatically adjust the indoor carbon dioxide concentration, realize real-time detection, and improve indoor air in real time In addition, the sensitivity of the detector is corrected by software to ensure the measurement accuracy of carbon dioxide concentration. The carbon dioxide detector can also expand its use, such as measuring the concentration of indoor toxic gases such as CO and formaldehyde, and can also detect the living indicators of indoor humidity, and display time on this basis to make it more functional.
