EFFECT OF PRESSURE ON emf OF THERMOCOUPLES
"Pressure" thermal emf's have been measured for constantan, Pt, Ni, alumel, Pt 10% Rh, Cu, chromel, and Ni 18% Mo for a DELTA T of 100 deg C over a pressure range 0 to 72 kbar. Corrections due to pressure for common thermocouples made of pairs of these metals have been deduced. A number of thermocouple pairs have been compared at temperatures up to 1200 deg C and pressures up to 58 kbar. Below 200 to 300 deg the-deviations between them agree quite well with the absolute data on single metals taken at DELTA T of 100 deg C. At higher temperatures the deviations diminish and generally reverse. It appears that the deviation sigma T of the readings of two thermocouples at a given pressure follow roughly the relationship sigma T = A(P) DELTA T + B(P) DELTA T/sup 2/, where DELTA T is the temperature interval in the pressurized zone, A(P) and B(P) are functions of pressure (roughly linear), and B(P) is generally opposite in sign to A(P) and is large enough to dominate the A(P) term at higher DELTA T's. (auth)
- Research Organization:
- General Electric Research Lab., Schenectady, N.Y.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-15-014863
- OSTI ID:
- 4050425
- Journal Information:
- Journal of Applied Physics (U.S.), Journal Name: Journal of Applied Physics (U.S.) Vol. Vol: 32; ISSN JAPIA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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