Temperature measurement using thermocouple
Simple temperature measurement using thermocouple is shown in the figure above. Hot junction is placed near the heat source, whose temperature is to be measured.
A sensitive mill voltmeter is directly connected across the reference junction. Now the deflection of the meter is directly proportional to the difference in temperature between the hot junction and reference junction.
Advantages of thermocouple:
- Cheaper than RTD.
- Rugged in construction.
- Used for wide temperature range.
- No external power is required.
Disadvantages of thermocouple:
- Non-linear output is produced
- Low output signal
- Instability