静态箱法气相色谱法自动检测农田N_2O排放

Automatic System Composed of Static Chamber and Gas Chromatograph for in-situ Measurement of N_2O Emission from Cropland

N_2O自动观测系统由微机控制电路和气路,使采样箱、气相色谱仪(GC)和积分仪自动工作,系统可连续采样分析,自动存储色谱数据,并可同时测定存储温度和辐射等气象数据。系统从放置于田间可自动开关箱盖的采样箱中,依次抽取空气样品,经除水、CO_2处理后送入气相色谱仪分析N_2O浓度,根据箱中浓度随时间的变化计算N_2O的排放通量。

A personal computer is used for the control of the electronic and pneumatic units of in-situ measurement of N_2O emitted from croplands. The introduce of sample, gas chromatographic analysis and integration of the data obtained are undertaken automatically. The ambient temperature and radiation can also be measured with the automatic system. Air samples are alternatively taken from the static chamber installed in fields. After removing of raoisture and CO_2, the sample is injected into GC/ECD system and the N_2O concentration in the headspace of each chamber is then analyzed. The variation of N_2O concentration in the headspace of each chamber can be obtained by which the N_2O emission rate from the area covered by the chamber can be calculated.