Dual Heated Humidity Sensor And Total Radiation Sensor Design

Conventional wireless radiosondes are usually equipped with high-precision temperature sensors,humidity sensors,barometers and other sensors to measure atmospheric temperature,humidity,pressure and other factors.In order to overcome the problem of water molecules covering the surface of the humidity sensor in the form of ice crystals or water droplets after the radiosonde exits and enters the cloud,which affects the accuracy of humidity measurement,this paper designs a dual-heated humidity sensor;At the same time,in order to develop a high-precision,low-cost total radiation sensor.This paper proposes a pyroelectric total radiation sensor with an aluminum radiation shield.The measurement of high-altitude temperature,humidity,and radiation intensity through two kinds of sensors aims to improve the sensors on conventional radiosondes as well as providing a new way of thinking for the radiosonde to exit and enter the cloud in the future.In order to improve the accuracy and response speed of high-altitude humidity measurement.Firstly,this paper designed a"Y"type dual-heated humidity sensor which use fluid dynamics method(CFD)to simulate and analyze the sensor.Secondly,the L-M algorithm is used to fit the heating time data.The result shows that the correlation coefficient of the fitting equation is 0.9970,and the fitting accuracy is high.At the same time,this paper proposes a total radiation sensor design.First of all,the three-dimensional model of the sensor is constructed,and the heat transfer analysis of the sensor is carried out by the fluid dynamic method,which preliminarily verifies the feasibility of the sensor design.Then use the L-M algorithm to fit the simulation data.The results show that the correlation coefficient of the fitting equation is 0.9989,the fitting accuracy is high,and the Kalman algorithm is used to filter temperature data measured by thermocouple.The results show that the Kalman algorithm can effectively reduce the temperature measurement error.Finally,a simulation experiment platform was built using a low-pressure wind tunnel and a solar simulator,and the performance tests of the two sensors on the ground and simulated high-altitude harsh environments were performed,and the experimental values were compared with the reference values.The experimental results show that for the measurement of humidity,the average humidity measurement error is 2.40%RH and the root mean square error is 2.43%RH under the ground standard atmospheric pressure environment.The measurement result is relatively accurate,and it is relatively dry relative to the ground standard humidity value.And in the high-altitude and low-pressure harsh environment simulated in the low-pressure wind tunnel,the measurement error gradually increases.The average humidity measurement error is 7.94%RH,and the root mean square error is 8.05%RH;for the measurement of radiation intensity,overall,In the ground or simulated high-altitude environment,the measurement error is not much different,the average of the radiation intensity measurement error is 5.66W/m~2,and the root mean square error is 9.89W/m~2.After analysis,the two sensors designed have achieved the expected results.