Intelligent pressure transmitter is a kind of intelligent transmitter formed by the combination of sensor technology and microelectronics technology.It has been widely used at present because of its great improvement in function,accuracy,reliability,maintenance and configuration compared with conventional analog transmitter.The intellectualization of the transmitter is mainly manifested in its ability of self-monitoring and long-distance communication,as well as its high reliability,wide range and stable temperature and pressure compensation performance due to the adoption of micro-mechanical electronic processing technology,ultra-large scale special integrated circuit(ASIC)and surface mounting technology.
Intelligent pressure transmitter is composed of intelligent sensor and intelligent electronic board.Intelligent sensor includes capacitive sensor,measuring diaphragm detection circuit,temperature sensor and temperature compensation circuit.Intelligent electronic board includes microcontroller and peripheral circuit to complete the conversion of pressure signal to 4-20 mA dc.It is used to measure the pressure of liquid,gas or steam,and then convert the pressure signal into 4-20 mA DC signal output.
Intelligent pressure transmitter is made by encapsulating silicon piezoresistive pressure sensor with isolation in stainless steel shell.It can convert the perceived liquid or gas pressure into standard electrical signals for external output,and is widely used in on-site measurement and control of industrial processes such as supply/drainage,thermal,petroleum,chemical,metallurgical,etc.
Intelligent pressure transmitter has reverse polarity and current limiting protection;laser resistance-adjusting temperature compensation,wide range,anti-corrosion,suitable for a variety of media;strong overload and anti-interference ability,stable performance;unique display head design,can choose analog and digital display head;zero and full range can be adjusted by hand-operated device,and range migration range is wide.
It can compensate the nonlinearity,temperature drift and time drift of the sensor automatically by software.Self-diagnosis can be made.After power-on,the sensor can be self-checked to check whether all parts of the sensor are normal and make a judgment.Data processing is convenient and accurate,and data can be automatically processed according to internal procedures,such as statistical processing,removal of abnormal values,etc.
It has two-way communication function.Microprocessor can not only receive and process sensor data,but also feedback information to the sensor,so as to adjust and control the measurement process.It can store and memorize information,and can store sensor's characteristic data,configuration information and compensation characteristics.
With the function of digital quantity interface output,the output digital signal can be easily connected with the computer or fieldbus.