Feasibility of Carbon Dioxide Detector Dissolved Gas Measurement
The new digital carbon dioxide detector is composed of carbon dioxide sensor, temperature sensor, temperature acquisition and control microcontroller, industrial computer, RS232 signal transmission circuit, voltage adaptation circuit, display screen, battery charging control circuit and instrument power supply surge overvoltage protection circuit, etc. , the carbon dioxide sensor uses a double-beam infrared carbon dioxide sensor to produce a compact infrared gas sensor. The sensor has a temperature compensation function and has no oxygen dependence. It is a general-purpose and intelligent miniature sensor. It is easy to use and is widely used in existence. For various occasions of carbon dioxide gas, it has the characteristics of stable performance, high precision, long life, less maintenance and low cost.
Carbon Dioxide Observation Instruments In 2011, the development of carbon dioxide observation instruments was started, and experimental observations were carried out at Chicheng Seismic Station, Houhaoyao Hydration Observation Station and Yangyuan Seismic Station. The working principle and system design of the new digital carbon dioxide detector, through experimental observation, proves the feasibility of carbon dioxide infrared gas sensing technology in the measurement of carbon dioxide fault gas and dissolved gas. This instrument can not only be used to observe the carbon dioxide content in station fault escaping gas and groundwater dissolved gas, but also play a role in unmanned carbon dioxide observation array and active fault detection under the condition of changing power supply mode and communication mode .
Using a digital carbon dioxide detector to observe and adopt the principle of infrared spectrum absorption is that the infrared absorption spectrum of carbon dioxide has a strong absorption peak at a wave number of 58550px-1. Its absorption relationship obeys the Lambert-Beer absorption law, the relationship between the outgoing light intensity I, the incident light intensity I0 and the gas volume fraction C. When the molar absorptivity is constant, the volume fraction of carbon dioxide can be calculated by detecting the intensity of the outgoing light. Due to the different molecular structures of different gases, the positions of their absorption peaks are also different. Using infrared rays with a wave number of 58550px-1 as the light source to detect the volume fraction of carbon dioxide is not easily affected by the concentration of other gas molecules.
The carbon dioxide sensor is placed in the middle of the outdoor fault soil gas gathering device. The gas gathering device is generally located in the sand layer at a depth of 5-10m below the surface. The host is installed in the observation room. The sensor is connected to the host with a cable with a length of about 15m. Feasibility of carbon dioxide infrared gas sensing technology in carbon dioxide fault gas and dissolved gas measurement. The new digital carbon dioxide detector developed by the project team has the characteristics of high sensitivity, high stability, networking and intelligence. Its observation accuracy and information volume are far greater than manual observation, and can replace the current manual observation at stations.
