Publication Date:
2019-07-12
Description:
Spools rotated to pull thermocouple wires through liquid nitrogen, while output voltage of thermocouple recorded on strip chart. Wires exposed to severe temperature gradients, amounting to overall change of 200 degrees C, where they enter and leave liquid nitrogen. If wires homogeneous, net output voltage zero. If inhomogeneity passes through liquid-nitrogen/air interface, resulting deviation of output voltage from zero seen immediately on strip chart. If inhomogeneity greater than allowable, reels stopped temporarily so inhomogeneity tagged before wound onto takeup reel.
Keywords:
PHYSICAL SCIENCES
Type:
LAR-14669
,
NASA Tech Briefs (ISSN 0145-319X); 17; 8; P. 48
Format:
text
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