1. Smart transmitters

2. Features of smart transmitter
Has a memory
Can perform calculations; perform self-diagnostics; reports faults; and can be communicated with from a remote location.
The sensor signal transmitter into a unified standard signal: 0/4-20mADC, 1-5VDC, 0-10VDc
Many different types of transmitters.
In addition to the functions are sensing there is amplification shaping function, the output control signals to a standard such as :4-20mA

3. Characteristics of smart transmitter
With automatic compensation capability through software for sensor non-linearity, drift, drift, etc
Data processing to facilitate accurate and automatic processing of data according to internal procedures, such as statistical processing to remove the abnormal values,
Two-way communication. Microcontroller can not only receive and process sensor data, can also be feedback to the sensors,
Can store the characteristics of the sensor data, configuration information, and compensation characteristics

4. with a digital interface to output can be easily output the digital signal and the computer or field bus connection.
The smart transmitter performs not only as the instrument system but also as the signal processing system
The user can obtain the useful data processed from the measured data in field by using the programmable smart transmitter.

5. Calibration information for RTD and other sensors are stored in the digital memory of the smart transmitter.
The smart transmitter can find the sensor and reservoir failure with embedded failure detection algorithm and can change the operation range by communication between the transmitter and the control room.
The smart transmitter can also eliminate the effect due to ambient temperature by measuring it for this purpose.

7. Two-Wire Transmitter

8. Two-wire transmitter designed for temperature and bridge sensors.
Zero, span, and linearization errors in the analog signal path can be calibrated via a standard digital serial interface, eliminating manual trimming.
Non-volatile external EEPROM stores calibration settings.
The all-analog signal path contains an input multiplexer, auto zeroed programmable-gain instrumentation amplifier, dual programmable current sources, linearization circuit, voltage reference, sub-regulator, internal oscillator, control logic, and an output current amplifier.

9. Automatic reset is initiated when supply is lost.
Current sources, steered through the multiplexer, can be used to directly excite RTD temperature sensors, pressure bridges, or other transducers.
op amp can be used to convert current into a voltage.
The XTR108 is specified for –40°C to +85°C.

10. Some distinct advantages of using Smart transmitter.
Ease of installation and communication, self-diagnosis, improved and digital reliability.
Smart transmitters are also less subject to effects of temperature and humidity than analog devices.
Smart transmitters also provide increased accuracy. And because can replace several different types of devices, using them allows for inventory reduction.

11. Block diagram of an intelligent industrial pressure
transmitter