Patent · US Expired

Pressure-sensitive variable-resistance hygroscopic fluid detector, and method

US5448603A · kind A · utility

1Cited by
10References
15Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 1, 1993
Grant dateSep 5, 1995
Priority date
Expiry dateNov 1, 2013

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02E30/30
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A fluid detector (20) has an enclosure (32) defining an internal chamber (33). The enclosure has a frangible wall portion (34). A sensor (46) is arranged within the chamber. The sensor has a hygroscopic portion (48), the electrical resistance of which changes depending upon whether the sensor portion is wet or dry. The chamber is normally filled with a dry fluid, such as nitrogen. The outer surface of the enclosure is exposed to another fluid containing water. When the pressure differential across the frangible wall portion exceeds a predetermined minimum value, the frangible wall portion ruptures to permit the sensor portion to become wetted. An ammeter (31) is arranged to determine the change in the electrical resistance of the sensor and to indicate the presence of the water-containing fluid within the chamber. The detector is particularly useful in determining the fluid-tight sealed integrity of a closed-end thimble having a portion inserted into a pressurized water reactor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.