Development of Automatic Monitoring System of Vertical Gradients for Air Pollutant
大气污染物垂直梯度自动监测系统的研制

An automatic monitoring system of vertical gradients for air pollutant was developed in the study.Air pollutant sampling at the three different heights was achieved by using two electromagnetic valves in this system.Based on the air pump in the instrument,the sampling gas were drawn into analytic instrument through PTFE tube and then their concentration were measured,the control of the electromagnetic valves and the gathering necessary data were carried by using a computer and an AD/DA conversation board.The results shown that the purging time can be set as one minute for a sampling tube of 25 m long,and the difference in the measured hourly concentration of O3,SO2,NO,NO2 caused by the different sampling tube length were not significant.