Pressure & Temperature Transmitter & Gauge

In industrial instrumentation,the transmitter provides 4-20 mA output,and it could mean the combination Gauge+transmitter,the gauge is the instrument in contact with the Temperature or pressure.

In other words,if you hear transmitter that means the output is 4-20 mA, a Gauge is the part in contact with the temperature and it could just have a voltage output like the thermocouple for example,the thermocouple transmitter makes it a 4-20 mA output,or the combination thermocouple+transmitter is simply called transmitter.

please tell about the internal construction of pressure transmitter(with block diagram) by which it can transmit pressure.

What i mean is temperature gauge eg mounted on top of a thermowell. In what case do we use temperature gauge and it what case temperature transmitter? Thanks in advence for the reply.

Let's try the Socratic method:

1) Which one(s) would you use for manual control? Why?

2) Which one(s) would you use for automated control? Why?

Good concept, however, original poster seems to be a green horn, it behooves you to break it down to him real slow and easy.

@ OP, gauge is a device with an indication (read-out, be it digital or analog), connected to the process, found on the field/process environment with or without remote connection, its sole purpose is for indication, nothing else, while a transmitter is a device connected to the process to send signal to a remote location for control/safeguarding purpose, it could also include indication purpose as well.