Process Engineering Division – Instrumentation and Automation Section – Daily Topics – Topic No. 2020-12-08
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Process Engineering Division – Instrumentation and Automation Section – Daily Topics – Topic No. 2020-12-08: Discussion question: When the detection system for 320, nickel-chromium/nickel-silicon thermocouples is in operation, the temperature at its cold end is t0 = 30°C. The instrument measures the thermoelectromotive force E(t, t0) = 39.17 mV. Determine the actual temperature of the medium being measured. (5 points are given only to those who provide the correct answer; additional points are awarded for a correct calculation process or detailed explanation.)
When the detection system of the nickel-chromium/nickel-silicon thermocouple is in operation, the temperature at its cold end is t0=30°C. The instrument measures the thermoelectric potential as E(t,t0)=39.17 mV. According to the table, the thermoelectric potential at E(30,0) is 1.2 mV. Therefore, E(t,0) = E(t,30) + E(30,0), which equals 39.17 mV + 1.2 mV = 40.37 mV. Referring to the table again, a thermoelectric potential of 40.37 mV corresponds to a temperature of 977°C. The actual temperature of the medium under test is 977°C.
According to the table, the thermoelectric potential E(30,0) is 1.2 mV. The thermoelectric potential E(t,0) equals E(t,30) plus E(30,0), that is, 39.17 mV + 1.2 mV = 40.37 mV. Again, per the table, a thermoelectric potential of 40.37 mV corresponds to a temperature of 977°C. The actual temperature of the medium under test is 977°C.
According to the table, the thermoelectric potential E(30,0) is 1.2 mV. The thermoelectric potential E(t,0) equals E(t,30) plus E(30,0), that is, 39.17 mV + 1.2 mV = 40.37 mV. Again, per the table, a thermoelectric potential of 40.37 mV corresponds to a temperature of 977°C. The actual temperature of the medium under test is 977°C.
According to the table, the thermoelectric potential E(30,0) is 1.2 mV. The thermoelectric potential E(t,0) equals E(t,30) plus E(30,0), that is, 39.17 mV + 1.2 mV = 40.37 mV. Again, per the table, a thermoelectric potential of 40.37 mV corresponds to a temperature of 977°C. The actual temperature of the medium under test is 977°C.
E(t0,0)+E(t,t0)=E(t,0)
The actual temperature of the medium under test is 977°C. I’ve learned it.*
The cold-end temperature of the chromium-nickel-silicon thermocouple is 30°C. According to the table, the thermoelectromotive force E(30,0) is 1.2 mV. The instrument measures the thermoelectromotive force as E(t,t0) = 39.17 mV. Therefore, E(t,0) = E(t,30) + E(30,0) = 39.17 mV + 1.2 mV = 40.37 mV. According to the table, a value of 40.37 mV corresponds to a temperature of 977°C; thus, the actual temperature of the medium being measured is 977°C.
According to the table, the thermoelectric potential E(30,0) is 1.2 mV. The thermoelectric potential E(t,0) equals E(t,30) plus E(30,0), that is, 39.17 mV + 1.2 mV = 40.37 mV. Again, per the table, the temperature corresponding to a thermoelectric potential of 40.37 mV is 977°C. The actual temperature of the medium under test is 977°C.
According to the table, the thermoelectric potential E(30,0) is 1.2 mV. The thermoelectric potential E(t,0) equals E(t,30) plus E(30,0), that is, 39.17 mV + 1.2 mV = 40.37 mV. Again, per the table, the temperature corresponding to a thermoelectric potential of 40.37 mV is 977°C. The actual temperature of the medium under test is 977°C.