Digital pressure transducer:
Digital pressure transducers used Quartz crystal frequency-output sensors to measure the parameter combined with an integrated microprocessor capability to deliver smart transmitters of pressure. These transmitters, operating under field conditions, can deliver comparable performance to the primary standards.
Placing the intelligence in the transmitter makes it easy for the user to configure a distributed measuring and control system from the host computer via a digital two – way bus
Quartz Electrostatic Pressure Sensors:
Quartz pressure sensors
Dynamic pressure measurements can be carried out using quartz sensors in which the applied force causes the development of an electrostatic charge across the crystal.
The application of force in the direction of one of the neutral axes Y establishes an electrostatic charge at right angles to it on the surfaces of the polar axis.
The magnitude of this charge depends on the dimensions of the quartz crystal, and a high load yield combined with good linearity and low-temperature sensitivity can be secured by selecting the appropriate shape.
Architecture for digital pressure transmitter:
The electronics architecture of an intelligent digital pressure transmitter is shown in figure below:
The digital interface board includes a precision clock, counter, microprocessor, serial port RS-232, serial port RS-485, and memory EPROM and EEPROM to store the operating program and calibration coefficients.
The microprocessor is monitoring incoming computer commands. The microprocessor selects the appropriate frequency signal source when a sampling command is received and uses a high – frequency time – base counter and
The measurement of
RS-232/RS485 interfaces control of all transmitter operations, including resolution, sample rate, integration time, baud rate, pressure adders, and pressure multipliers