system composition

The greenhouse gas profile observation system includes a sample gas collection and processing unit, a greenhouse gas analysis unit, a calibration unit, a control unit, a power supply unit, a data acquisition, storage, and transmission unit, and system installation accessories.

System working principle: Under the action of the sample gas sampling pump, the sample gas passes through sampling ports, filters, and flow limiting holes arranged at different heights, and is transported to a low flow multi-channel controller. According to a pre designed program, the solenoid valve in the multi-channel controller switches one of the gas paths for analysis. The selected sample gas path enters the analyzer through a low flow dryer under the action of the analyzer sampling pump. rest11The road gas is evacuated in order to shorten the sampling period and ensure that the airflow continuously flushes the pipeline, avoiding the deposition of particulate matter.

PGHC2APTopology diagram of greenhouse gas profile observation system

Sample gas collection and preprocessing unit

The sample gas collection unit is produced by TiannuojieTN-SAMPLEThe sampling head includes a rain cover, insect screen, filter, flow restriction hole, and installation components. Insect proof nets are used to filter fallen leaves, insects, and larger particles, while filters are used to filter larger particles7umThe above dust and rain cover are used to protect the filter. Sampling pipeline adopts1/4inchSynflex 1300Aluminum plastic pipe or PTFE pipe. The auxiliary sampling pump adoptsPakerThe dual head sampling pump,.

Greenhouse gas analysis unit

Greenhouse gas analyzer adoptsPicarroThe high-precision analyzer produced by the company adopts a time domain based approachFourth generation wavelength scanning cavity ring down spectroscopy technology（WS-CRDS），This principle establishes a linear relationship between the concentration of the gas to be measured and the time it takes for the characteristic wavelength of the gas to decay in the gas chamber, and measures the concentration of the gas. And wavelength scanning cavity oscillation spectrum（WS-CRDS）Technology establishes up to20A kilometer long optical path, which can be monitored in a very short timeppbLevel evenpptHorizontal gas. Compatible with multiple greenhouse gas analyzers.

G2301 : CO2\CH4\H2OGreenhouse gas analyzer

G2401 : CO2\CO＼CH4 \H2OGreenhouse gas analyzer

G2201-i: CO2\CH4inδ13CIsotope abundance,CO2\CH4 \H2Oconcentration

L2130-i:δ18O\DIsotope abundance

L2140-i:δ18O\δ17O\D\Isotope abundance andO17surplus.

control unit

The control unit is produced by TiannuojieMC-01Multi channel controller, mainly composed of two three-way valves, assists the sampling pump to collect sample gas from different heights in real time. According to the pre programmed program, only one sample gas is sent to the analyzer for analysis, and the rest of the gas is discharged through the manifold to ensure that the gas path is always in a flushing state, avoid dust retention, and reduce sampling waiting time.

The system can be accessed at most8Layer gas.

Calibration unit

The calibration unit includes zero gas, full-scale gas, and pressure reducing valve. Zero gas can be dry air (excludingCO2andCH4）,The full-scale gas can be selected according to the concentration range of the local project.

Power supply unit

The system adopts220V/50HzPower supply. The power supply system is equipped with overcurrent protection devices,UPSAnd switch power supply. DC power supply is used to power the data collector,UPSUsed to power the analyzer and switch power supply, ensuring that the system can operate in the event of a power outage15minute.

Data collection, storage, and communication unit

This system adoptsCampbellThe company'sCR3000As a data collector, the data collector has a network portRS232、SDI-12、RS485Rich communication interfaces such as analog input and support for the majority of communication protocols make it very convenient to connect to external communication devices for data transmission. The system can also be additionally connectedGPRS/CDMAWireless communication module (specific options depending on the observation location network). The data center only needs to open the corresponding communication port to remotely access the data collector, browse and download observation data.

System features

Analytical equipment can be selectedPicarroMultiple greenhouse gas analyzers;

Multi channel valve group realizes the time-sharing transmission of gases with different layer heights to the analyzer;

The data collection and processing unit realizes the collection and storage of data;

The system adopts negative pressure sampling, and the pipeline pressure is lower than atmospheric pressure-30kPaTo avoid condensation of gas during transmission;

The patented high-precision wavelength monitoring technology can lock in the characteristic absorption spectrum of the target gas, reduce the influence of interfering gases on the measurement of the target gas, and ensure ultra trace measurement in mixed gases;

The patented optical attenuation oscillation technology enables the optical path to reach20km,Make the measurement reachppbGrade accuracy;

The precise temperature and pressure control system ensures the linearity, accuracy, precision, and stability of the instrument;

The device can automatically maintain the measurement chamber at a constant negative pressure, and the near-infrared absorption spectrum formed by the target gas under negative pressure has narrower absorption peaks and higher resolution;

PicarroThe system is compact and sturdy, requiring minimal maintenance, no sample preparation or drying, easy and fast installation, and can be used for unmanned long-term work in harsh environments.

The system has good scalability and can be connected to meteorological observation equipment

application area

Global research on carbon, nitrogen, and water cycles provides accurate data sources for carbon trading

Combining climate change data to study the impact of greenhouse gas emissions on climate change