Improved vacuum thermocouples

Author

Levinson, H. ; Inglis, B.D. ; Kinard, J.R. ; Stollery, D.E.

Author_Institution

Best Technol. Inc., Seattle, WA, USA

fYear

1994

fDate

June 27 1994-July 1 1994

Firstpage

359

Lastpage

360

Abstract

Prior construction of single junction vacuum thermal convertors (SJTCs) did not consistently produce units with AC-DC differences of a few ppm or less. Four improvement modes have been introduced. (1) Elimination of flaming during the making of the mounting bead. (2) Changing of the feed-through posts from Dumet to platinum-iridium. (3) Decrease of the Thomson coefficient by changing from nickel-chromium to Evanohm heater wire. (4) Lowering of the temperature gradient along the heater wire in the vicinity of the thermocouple. SJTCs can now be constructed with AC-DC differences of less than 0.3 ppm at a high yield.<>

Keywords

Peltier effect; chromium alloys; iridium alloys; measurement standards; nickel alloys; platinum alloys; thermocouples; units (measurement); AC-DC differences; Dumet; Evanohm; Ni-Cr; Pt-Ir; Thomson coefficient; feed-through posts; flaming; heater wire; mounting bead; nickel-chromium; platinum-iridium; temperature gradient; vacuum thermocouples; Australia; Converters; Laboratories; Manufacturing processes; Physics; Production; Temperature; Testing; Welding; Wire;

fLanguage

English

Publisher

ieee

Conference_Titel

Precision Electromagnetic Measurements, 1994. Digest., 1994 Conference on

Conference_Location

Boulder, CO, USA

Print_ISBN

0-7803-1984-2

Type

conf

DOI

10.1109/CPEM.1994.333359

Filename

333359