Low Radiation Error Temperature Sensor For Meteorological Observation

In the process of meteorological detection,temperature sensor measurement accuracy can be affected by long-wave radiation from the ground,direct radiation from the sun,and reflected radiation from the ground and clouds.Direct solar radiation is the main factor affecting the accuracy of temperature measurement.Traditional meteorological stations generally use thermometer screens and radiation shields to reduce radiation errors caused by direct solar radiation.However,due to the large size of these devices,they are not suitable for sounding platforms.In order to reduce the solar radiation error of the sounding sensor system,a low radiation error temperature sensor system design is proposed in this paper.The system includes the data collection and processing systems and the information receiving subsystem.The data acquisition and processing system adopts the thermocouple temperature sensor with low radiation error,and the Ptl0O platinum resistor is used as the thermocouple cold junction compensation device.A low noise 24-bit S-A analog-to-digital is utilized here to set up the temperature measuring circuit,and adopt a variety of ways to improve the system measurement precision.The test indicates that the RMS noise of the circuit is 0.076 mK.A computational fluid dynamic(CFD)method is utilized to simulate the Thermocouple temperature sensor probe.Simulation results suggest that the new design helps to reduce the solar radiation error.And the rationality of the sensor's design is verified preliminarily.Two variables of the radiation error correction equations is fitted by Levenberg-Marquardt algorithm,in order to provide accurate correction data when factors continuous change.Using the low-pressure wind tunnel and the solar simulator to set up a simulation of the solar radiation error simulator and comparing the measurement results of the simulation device with the simulation data.The experimental results show that the solar radiation error of the thermocouple sensor at the altitude of 0?20 km is only 0.07 °C?0.30°C,which is lower than the error value of the conventional bead thermistor at the same altitude;In this paper,a solar radiation error correction equation is proposed by software simulation,shows that the average offset and root mean square(RMS)values between the corrected values and measured values are only 0.011 K and 0.014 K.The radiation error correction equation has a good correction effect.