Design And Error Analysis Of Temperature Measurement Part In Temperature Calibration System For Automatic Meteorological Station

Our country is pone to meteorological disasters. The use of automatic weather station provide valuable meteorological data for meteorological observation, increased the valuable experience of meteorologists, and to be effective in the prevention of meteorological disasters. With the wide application of automatic weather stations in various fields, the calibration work is more and more important. Temperature is a very important part of automatic weather station data. Due to environmental factors and the own factors of automatic weather station, after operated a period of time in the outdoor temperature measurement accuracy can be affected. In order to ensure the normal operation of the automatic weather station temperature measuring part and improve the accuracy of meteorological observation, the temperature part of the automatic weather station need to be regular calibration. According to common temperature calibration method of automatic weather station, design the temperature measurement part in the automatic weather stations temperature calibration system has very important practical significance.This paper analyzes the temperature measurement precision and temperature measurement range of some domestic present automatic meteorological station, then determined the design target of temperature measurement system. Suitable temperature sensors is selected after comparing the common temperature sensors, and design the overall scheme of temperature measurement system.In order to improve the accuracy of the temperature measurement system, and can applied in the automatic weather station temperature calibration system, first using the differential input method to improve the anti-interference ability of system, then analyze the possible factors can lead to error in the design of system, in view of these factors, some corresponding measures to eliminate or reduce the error is put forward.The hardware of the temperature measurement system use PT1000as the temperature sensor, microcontroller AT89S52as the processor. The test current producing module, signal conditioning module, AD conversion module, isolation module and so on constitute hardware platform, and applies the measures to reduce error in the hardware circuit to improve the accuracy of temperature measurement system.The software of this system is divided into the upper computer software and lower computer software. The lower computer software part puts forward the whole scheme, and introduces the function and process of pretreatment, filtering, ADC processing and data processing module. The PC software part puts forward the whole scheme and introduces the function and process of the serial processing, data receiving and storage, Excel generation and graphic processing module.In order to validate the temperature measurement system can meet the requirements of using in automatic weather station temperature calibration system, first some theoretical knowledge of metrological verification and the commonly used temperature calibration method was introduced, then based on the traceability of quantity values using contrast method to experiment for the temperature measurement system, and the error analysis of the system using experimental data show the temperature measurement system can achieve design goal. Finally do the experiment in laboratory to verify the PC software, and the results show that the system can achieve design goal.