Apparatus for detecting the presence of a liquid

Patent · Tue Oct 31 04:00:00 EST 1995

OSTI ID:131905

Kronberg, J W

An apparatus is described for detecting the presence of a liquid in a region, including an electrically passive sensor adapted for contacting the liquid, and an electrically active detector. The sensor is a circuit with a pair of spaced-apart terminals connected to a switch that closes in the presence of the liquid. The detector carries an alternating current with a resonant frequency. When the sensor is placed in a region and liquid is present in the region, the circuit of the sensor is closed. By bringing the detector close to the sensor, an alternating current is induced in the sensor that will, in turn, alter the resonant frequency of the detector. The change in the resonant frequency is signaled by a transducer. The switch can operate by a change in conductivity of a material between the terminals of the sensor or by expansion of a liquid absorber that pushes the two terminals together, or by a change in the conductivity of the space between the terminals as a result of the presence of the liquid. The detector generates an audible or visible signal, or both, in response to the change in current. 12 figs.

• Research Organization: Westinghouse Savannah River Co
• DOE Contract Number: AC09-89SR18035
• Assignee: Dept. of Energy, Washington, DC (United States)
• Patent Number(s): US 5,463,377/A/
• Application Number: PAN: 8-133,299
• OSTI ID: 131905
• Country of Publication: United States
• Language: English

Related Subjects

44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
ALARM SYSTEMS
DESIGN
DETECTION
ELECTRIC CONDUCTIVITY
FREQUENCY DEPENDENCE
LIQUIDS
MONITORS
OPERATION
SWITCHING CIRCUITS