How to wire a thermocouple to get analog value?

Hello friends..You can see the thermocouple in the above picture..To control machines with temperature related applications,such as heating furnace,hot mesh belt furnace,e tc..,we need analog feed back to the plc to control the machine..
So,we use thermocouple for this purpose..

A thermoelectric device for measuring temperature, consisting of two wires of different metals connected at two points, a voltage being developed between the two junctions in proportion to the temperature difference.

Wiring :
There are two terminals in a thermocouple..One is positive and other one is negative..Connect these terminals to analog device to read the analog temperature values..