Fig. 1. (a) Diagram of air chamber structure; (b) Simulation of optical chamber

Fig. 2. Block diagram of system design

Fig. 3. Power module design

Fig. 4. Design of light source drive

Fig. 5. Module design of main control

Fig. 6. Module design of temperature and humidity collection

Fig. 7. (a) Preamplifier circuit; (b) Post-amplification circuit

Fig. 8. Main program flow module

Fig. 9. Chart of stability fluctuation

Fig. 10. Graph of relationship between concentration and peak-to-peak value at 25 ℃

Fig. 11. Relationship between the concentration value and the peak-to-peak value at different temperatures

Fig. 12. Relationship between temperature difference and voltage difference