The Application Of SMS In Open Channel Flowing Measurement System

The flow measurement in U-shaped channel has been studied combined the 948 subjects of Ministry of Water Resources and the World Bank's loan project of improvement project of irrigated area within the Guanzhong in this paper. Based on the boundary layer theory, a theory method and formulae has been put forward which calculate the flowing in U-shaped channel long throat flow-measuring flume and the validity of those formulae has been proved by test. Those formulae established the foundation that the theory to calculate the long throat flow-measuring flume. This paper also studied the effect of the throat length, the channel obliquity and channel slope rate and the result shown that the effect of the channel obliquity and channel slope rate small. The optimized formulae of channel length has been gained and presented the standard design of U-shaped channel long throat flow-measuring flume.This paper have studied the automation of open channel measurement system of flowing, have probed into the Short Message Service (SMS) of GSM, AT command of sending and receiving SMS, classification, SMS network structure, transmission course and the mode of sending and receiving SMS, and have proposed the system structure frame offlow measurement based on SMS in irrigation area. The flow measuring instrument and sensor especially has been developed. It can meet in irrigated area where no power, no communication line, nobody on duty and the natural conditions poor situation. The characteristic of this system can realize some function, such as the automatic collection of the water level information, communication, statistical report form and charge fee etc. The floater water level sensor has been proposed according to situation in irrigated area, and the method of installation and method of returning to zero has been discussed.The sensitivity and precision have been examined by test. Result shown that the floater water level sensor are precious and cheap, and it's fabrication cost is about 1/3 of other sensors which the irrigated area uses at present easy to use. Based on the principle of satisfied with the function, lower costs , economizing energy consumption, the hardware have been planned, the bus structure have been confirmed with I2C and some type of the devices have been selected according to the needs of structure, including CPU, memory, A/D chip, real-time clock, GSM chip and power part. The paper also provided the interface circuit.The apparatus software and computer software have been designed. As apparatus can run by MCU, it's software adopted C language and assembler language. The mainly program used the structurization programming while the debugging that seldom to use adopts interrupt mode. The computer program has been written by C ++ Builder, and it main operation series port and databases. The series port is the communication port that gathered the data from GSM network, and it adopted the function of API that Microsoft offered. Database part set up the empty form by Access, and operated some function, such as input, calculation and inquiring etc. by C ++Builder.