Study On Intelligent Processing Unit Of Versatile Flow Sensor

The flowmeter play an important role in industrial production process , such as storage transportation and business accounting of energy sources, environment protection, biotechnology, national defense, scientific research ,etc.The flowmeter's sensors produce frequency pulse signal, such as turbine, vortex and positive displacement flowmeter which are widely used . However, the structure principles and the signal generation method of these flowmeter sensors are different. The sensor with different operating frequency have different measurement range and liner degree. In addition, the demand is different on temperature compensation and pressure compensation according to fluid measured. So it doesn't have a united standard in different flow metersTo solve the questions exist in the flowmeters which can output the frequency signal, the main work which I have done is shown as follows:1. The hardware of versatile intelligent process unit of the flow sensors was designed. This system is mainly composed of microprocessor , liquid crystal display , button and peripheral circuit. The hardware system has the low consumption. multi-parameter such as temperature , pressure , frequency , instrument coefficient can be displayed.2. The software system of the versatile intellectual unit of the flow sensors was designed. Real-time multi-task operating system was introduced. Instrument coefficient was set online while the flow is measured. To the pulse data, a new sample technology was adopted, the measured range was widenned (0～65535Hz ), the precision of measurment was improved.3. C language was adopted to program the software system for its advantage of portable and fast upgrade. The problem of low calculating precision for C compile to count float point number was solved especially.4. The hardware system can store all kinds of parameters and total amount flow for a long time . The reading and writing times of EEPROM has prolonged abundantly and reasonably, EEPROM's life is up to more than 15 years.5. Analysing many kinds of precision compensation method , a kind of precision compensate was mentioned and the error of the sensor was reduced.A large number of experimental datas abtained in laboratory of flow of Tianjin university proved that the intelligent flow process unit has high accuracy and wide measure range and low consumption characteristic.The design was a new method to realize measurement for the above flowmeters, at the same time it has extensive practical value.