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A temperature threshold detector (10) comprises a first electrical conductor (11) and a second electrical conductor (12), which are separated by a spacing structure (13). The first and second electrical conductors (11 and 12) are made of metals that are dissimilar from each other in terms of oxidati

A temperature threshold detector (10) comprises a first electrical conductor (11) and a second electrical conductor (12), which are separated by a spacing structure (13). The first and second electrical conductors (11 and 12) are made of metals that are dissimilar from each other in terms of oxidation potentials or thermally generated electromotive force. The spacing structure (13) is made of a material whose electrical resistivity is temperature dependent so that, when exposed to a temperature below a predetermined threshold value, the spacing structure (13) provides electrical isolation between the first and second electrical conductors (11 and 12). However, when exposed to a temperature above the predetermined threshold value, the spacing structure (13) enables an electromotive force to develop across the first and second conductors (11 and 12). This electromotive force is indicative of temperature rise above the predetermined threshold.

대표청구항 ▼

An apparatus for detecting a leak in a vessel seal, said apparatus comprising: (a) an elongate sensor responsive to a temperature rise above a predetermined value, said temperature rise being attributable to the leak in said seal, said sensor being positionable circumjacent said seal, said sensor co

An apparatus for detecting a leak in a vessel seal, said apparatus comprising: (a) an elongate sensor responsive to a temperature rise above a predetermined value, said temperature rise being attributable to the leak in said seal, said sensor being positionable circumjacent said seal, said sensor comprising: (i) a first electrical conductor, (ii) a second electrical conductor, and (iii) a spacing structure separating said first and second electrical conductors, said first and second electrical conductors being made of dissimilar metals, said spacing structure being made of an ionic salt selected from the group consisting of KNO3 and NaNO3, said ionic salt having an electrical resistivity that is temperature dependent so that said spacing structure provides substantial electrical isolation between said first and second electrical conductors when exposed to a temperature below said predetermined value, and so that said spacing structure acts with the dissimilar metals of said first and second electrical conductors when exposed to a temperature above said predetermined value to cause a self-generated electromotive force to develop across said first and second electrical conductors, and (b) an instrument for indicating temperature rise above said predetermined value, said instrument having a first electrical lead connected to said first electrical conductor and a second electrical lead connected to said second electrical conductor, said electromotive force driving said instrument to indicate said leak.