Robert B Dechurch

US Patent:

53131851, May 17, 1994

Filed:

Feb 8, 1993

Appl. No.:

8/015351

Inventors:

Robert M. DeChurch - Canfield OH

Assignee:

Furon Company - Aurora

International Classification:

H01C 304
H01C 710

US Classification:

338 22R

Abstract:

A continuous temperature sensing cable formed of a polymer containing conductive and semi-conductive fillers such as polyethylene with carbon black, powdered metals and metal oxides. The composition is extruded over a pair of elongated substantially parallel conductors which are spaced apart along the longitudinal length of the cable. The conductors are single-endedly connected to a control/alarm device for monitoring the continuous length of the temperature sensing cable. A critical voltage is applied single-endedly to the conductors and serially connected to an audible alarm to detect tunneling conduction when operated at a temperature near the melt temperature of the composition whereat the composition exhibits a negative temperature coefficient (NTC).

US Patent:

51855941, Feb 9, 1993

Filed:

May 20, 1991

Appl. No.:

7/703282

Inventors:

Robert M. DeChurch - Canfield OH

Assignee:

Furon Company - Aurora OH

International Classification:

G08B 1706
H01C 304

US Classification:

340596

Abstract:

A continuous temperature sensing cable formed of a polymer containing conductive and semi-conductive fillers such as polyethylene with carbon black, powdered metals and metal oxides controlled within the range of from about eight percent (8%) to about fifteen percent (15%). The composition is extruded with a pair of elongated substantially parallel conductors which are spaced apart along the longitudinal length of the cable. The conductors are single endedly connected to a control/alarm device for monitoring the continuous length of the temperature sensing cable. The control/alarm device may be a time domain reflectometer TDR for accurate determination of localized discontinuities caused by high temperatures along the length of the temperature sensing cable. Alternatively, a critical voltage may be applied single-endedly to the conductors and serially connected to an audible alarm to detect tunneling conduction when operated at a temperature near the melt temperature of the composition.