The Design And Research Of Pluviometer Verification System

Pluviometer is an important instrument to precipitation observation. Its accuracy directly affects the reliability of the measurement data, especially for testing the effect of artificial precipitation and meteorological research, so its measurement accuracy is very important. In order to guarantee the precision and reliability of pluviometer, it is very necessary to verify the pluviometer. Currently the verification method for pluviometer is mainly using standard containers or through high-accuracy tipping bucket pluviometer, or through manual method with measuring cup. The entire process is inefficient, and could easily lead to human errors, so we need a verification system which can generate the required rainfall automatically.In the thesis, a pluviometer verification system which can be set simulative rainfall intensity and precipitation was designed. It can automatically adjust the current velocity and the flow of water. The pluviometer verification system consists of storage room level control system, constant pressure water supply system, rainfall simulation system, and interactive interface system. The storage room is connected with outside water pipes through the solenoid valve. The ultrasonic transducer above the storage room is used to measure the current liquid level, and then to control the operation of the solenoid valve by industrial personal computer. Using Fuzzy-PID algorithm to control the constant pressure water supply system, whice can make the pressure of experiment pipeline more stable. By controlling the servo valve to regulate the different simulated rainfall and make the flow more accurate and stable by continuous feedback of internal regulation. During the verificating, the system can be set simulative rainfall intensity and precipitation through the mall-machine interface. According to the simulative parameters, the system calculates that how much the servo valve should move, then adjust the valve opening by industrial personal computer. When the flow of water reaches the set precipitation, the processor controls servo valve to be closed. Finally, measure the actual water discharge by electronic scale, then, we can judge whether it meets the precision demand through the predication precision.At the end of this thesis, the standard uncertainty evaluation of the entire pluviometer verification system is calculated, which proofs that the system meets the design requirements. Compared with traditional verification methods, the automatic pluviometer verification system can avoid the uncertain factors by manual operation and improve the verification accuracy. By using the microcomputer to conrol the entire examination process, the labor intensity of operators has been reduced, the labor efficiency has been enhanced, so this pluviometer verification system has a good prospect.