Iron-constantan thermocouple tables

Iron-constantan thermocouple tables, 15-1 to 9 Irradiance of the sun, 14-18 Isoelectric point, amino acids, 7-1 to 2 Isotopes, summary of properties, 11-56 to 253 Isotopic abundance, 1-14 to 17,11-56 to 253 ITS-90... 

Some electric tube furnaces incorporate a p3n ometer, which is not required in any of the experiments described in this manual, though Experiments 13 and 14 can be run by using an electric tube furnace at controlled temperature instead of an oil bath if so desired. A pyrometer may easily be improvised with iron and constantan wires twisted together and spot-welded to provide the junctions. The hot junction is placed against the outside of the combustion tube in the center of the heated portion and bound in position by asbestos tape, which also serves as insulation. The cold junction is kept in ice and water, and the electromotive force is measured with a millivoltmeter. With the cold junction at 0°C and the hot junction at 200°C, the electromotive force of the iron-constantan couple is given in tables as 10.77 millivolts. For accurate work the couple used should be calibrated and to assure uniform temperature distribution and electrical shielding, the combustion-tube and thermocouple wires should be encased in a tubular metal shield that fits inside the furnace and is groimded. 

For general instruction on the use of thermocouples, see ASTM Manual on the Use of Thermocouples in Temperature Measurement (ASTM, 1981). The National Bureau of Standards publishes a complete set of thermocouple tables (Powell et al., 1974), and White (1987) provides a table of output voltage versus temperature for copper-constantan and two gold-iron thermocouple materials for cryogenic work. 

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