Instrumentation Field Transmitters

temperature transmitters. See these two

are temperature transmitters. You can

see the tag name on the top. This is the

canop TT means temperature transmitter.

This is area code. This is transmitter

number tag name. And this is the cable

coming from the thermouple

and this is the cable going to the DCS

system. And this is one flow transmitter

DP type differential pressure based flow

transmitter. All these instruments are 4

to 20 milliamp based instruments. They

support hot protocol also for the

configuration of these instruments. All

instruments in the industries operates

on 4 to 20 millia based signals. Every

industry wherever you go you will find 4

to 20 millia based instruments

and these are two wire instruments. What

is two wire? In this single cable see

this is the single cable blue color

cable connected to the transmitter. This

single cable provides power supply to

the transmitter and then carries this 4

to 20 millia output to the DCS system

using two wire that means one pair

cable. You can see this is flow

transmitter only one cable is connected

blue color cable. This is a two wire

instrument. That is why it is very

advantageous to the installation cost

optimization when compared to three wire

or four-wire systems. We have three-wire

instruments. Four-wire instruments also

available but majority the popular one

is two wire instrument.