On a single graph plot the calibration curves for the three type E calibration t
ID: 2084863 • Letter: O
Question
On a single graph plot the calibration curves for the three type E calibration thermocouples and compare them to the standard calibration data provided in the attached table. On a second graph repeat this plot for the type T calibration thermocouple. For discussion purposes, it may also prove useful to graph the calibration data for the two soldered thermocouples on a third graph. Plot the semi-log transient temperature history for the calibration thermocouples. Use a linear curve fit of this plot to determine the time constant by the first method above. Estimate the time constant of each calibration thermocouple using the second method above (the e^-1 method). Provide a table of the time constants for the four calibration thermocouples. To what precision (in millivolts) are you reading the temperature? What effect does the method of junction have on the thermocouple calibration and time constant? What effect does theory tell us it should have? What differences do we see between the chromel/constantan and the copper/constantan thermocouples? Why? Compare the two methods of estimating the time constant. Which one is better, and why? What errors may be introduced by measuring temperature with a thermocouple? You may wish to consider the heat transfer modes acting on the thermocouple What role does the reference junction play in thermocouple readings? What is the resolution of the board, and how does this impact the data? Consider both the principle of operation and its implications.Explanation / Answer
1)seebeck effect they have-thermal emf is generated when the junctions are at different temperatures. This phenomenon is known as the Seebeck effect., Such a device is called a thermocouple.
2)>cold-worked copper being thermoelectrically positive to the same material annealed. the magnitude of the thermal emf between the cold-worked and annealed material depends upon the amount of cold working. Differences as large as 24 between cold-rolled and annealed samples (junctions at 0° and 300° have been brought to our attention).