Comparison of Thermocouple Types
Thermocouple types and probes and thermocouple cables used for measurement of temperature, mode of furnace thermocouple working and high-temperature thermocouple working procedure, and the functioning of the thermistor. Calibration of temperature sensors, the material of construction of various thermocouples based on the utilization, mechanism of fitting the thermocouple to the process equipment, and working principle of thermocouple testing. B, E, J, K,R, S, T types of thermocouple comparison
Sr no | Type | Positive wire | Negative wire | Temperature range 0C | Linearity |
1 | B | Pt-70—Rh-30 | Pt-94—Rh-6 | 0 to 1860 | Good at high temperature |
2 | E | Chrome | Constantan | -196 to 999 | Good |
3 | J | Iron | Constantan | -196 to 760 | Nearly linear between 149 to 438 |
4 | K | Chrome | Alumel | -190 to 1371 | Most linear |
5 | R | Pt-87—Rh-13 | Platinum | -18 to 1704 | Good at high temperature |
6 | S | Pt-90—Rh-10 | Platinum | -18 to 1760 | Good at high temperature |
7 | T | Copper | Constantan | -190 to 399 | Same as J |
8 | Tungsten W | W 74 –Re 26 | -18 to 2316 | Good at high temperature | |
9 | W 94 –Re 6 | W 74 –Re 26 | -18 to 2316 | Good at high temperature | |
10 | Copper | Gold – Cobalt | -268 to -18 | Linear above 60k | |
11 | Ir 40- Rh 60 | Ir | -18 to 2093 | Good at high temperature |
Pt- Platinum
Rh- Rhodium
W- Tungsten
Re- Rhenium
Ir-Iridium
In various corrosive environments, the instrument should function and measure the temperature, for that purpose a list of the thermocouple will help to determine the right suitable temperature-measuring instrument.
Sr no | Type | Positive wire | Negative wire | Suitable atmosphere |
1 | B | Pt-70—Rh-30 | Pt-94—Rh-6 | Inert or slow oxidizing |
2 | E | Chrome | Constantan | Oxidizing |
3 | J | Iron | Constantan | Reducing |
4 | K | Chrome | Alumel | Oxidizing |
5 | R | Pt-87—Rh-13 | Platinum | Oxidizing (fast response) |
6 | S | Pt-90—Rh-10 | Platinum | Oxidizing |
7 | T | Copper | Constantan | Oxidizing or reducing(good corrosion resistance) |
8 | Y | Iron | Constantan | Reducing |
9 | — | Tungsten W | W 74 –Re 26 | Inert or vacuum(high temperature) |
Transportation of 8000-liter storage tank; Report
Report: Storage tank of lightweight with an 8000-liter capacity is been transported by a transportation truck ignoring the safety rules. The tank is placed horizontally and supported with some sandbags to prevent it from rolling out. Four supporting bars are welded temporarily along the length of the outer surface of the tank on either side of the truck platform. Transporters follow their thumb rule to decrease the transportation charges, neglecting the risk and safety issues. This type of practice is not allowed in developed countries but is frequently seen in developing countries.