Design Of High-precision Temperature And Pressure Control System For Spectral Measuring Instrument

In recent decades,environmental pollution caused by human activities and industrial production has become increasingly serious,China is facing environmental governance challenges,therefore,the realization of automatic analysis optimization and monitoring of the production process is an important means of supervision.Spectral measurement is a qualitative and quantitative scientific analysis method,with its advantages of high measuring accuracy and fast response speed,it has become a focus of research on pollution gas monitoring,spectral measurement enables high sensitivity,low detection limit gas concentration measurement and analysis of important physical quantities for sample gases.In the process of spectral measurement and analysis,the temperature and pressure changes of the sample gas become the main factors affecting the measuring results,therefore,maintaining the stability of temperature and pressure and improving the control accuracy have important practical significance for the development of high-precision spectral measuring instruments.This paper proposes a set of high-precision temperature and pressure control system for spectral measuring instruments,this system is designed and optimized from the aspects of instrument structure,circuit design and control algorithms.Based on this system,the control accuracy of temperature and pressure was measured in 42 hours,system's long-term temperature control accuracy can reach 0.003?,and long-term pressure control accuracy can reach 5.3 Pa;Under pressure control but without temperature control,the measuring results of methane gas concentration 12.1 ×10-6,the deviation 1? is 3.3 ×10-6;Under temperature and pressure control,the fluctuation of measuring results is 4.0 × 10-6,the deviation 1?is 0.6 ×10-6.The results show that the high-precision temperature and pressure control system can improve the measuring accuracy and stability of the spectral measuring instrument,and verify the reliability and feasibility of the system.This temperature and pressure control system for spectral measuring instrument meets the experimental and production standards,and provide reference for the design of similar high-precision spectral measuring instruments.