US4933887A — Process and apparatus for the determination of th…

Claim 1

Independent Claim 267 words

A process for the in situ determination of thermophysical properties of a solid material, primarily for determination of thermal conductivity and thermal diffusivity in a certain volume of a solid, stationary material to be tested, comprising the steps of making a hole in said material, inserting into said hole in said solid stationary material a probe having a number of temperature sensors and a heat source, generating a temperature field varying with time with said heat source by way of driving with a known heating power input, measuring the temperature field at a plurality of measuring points on the inside surface of said hole in the material to generate temperature data for said plurality of measuring points, said sensor being in intimate contact with said material at said measuring points whereby the space for convection currents in said hole is minimized and measurement may be taken substantially without the interference of convection currents, determining selected properties by calculation from said temperature data and the known heating power input, wherein said point-like heat source is used in contact with said material for heating to form substantially spherical isotherms in a perturbed portion of the material to be tested to induce a measurable temperature change at the measuring points, said measuring points at different distances from the heat source being arranged along a straight line passing through the heat source and intersecting the isotherms along their diameter, wherein the measuring points are selected so that the maximum size of the point-like heating element is substantially smaller than the distance between the point-like heating element and the farthest measuring point.

Claim 2

Dependent Claim 267 words

A process for the in situ determination of thermophysical properties of a solid material, primarily for determination of thermal conductivity and thermal diffusivity in a certain volume of a solid, stationary material to be tested, comprising the steps of making a hole in said material, inserting into said hole in said solid stationary material a probe having a number of temperature sensors and a heat source, generating a temperature field varying with time with said heat source by way of driving with a known heating power input, measuring the temperature field at a plurality of measuring points on the inside surface of said hole in the material to generate temperature data for said plurality of measuring points, said sensor being in intimate contact with said material at said measuring points whereby the space for convection currents in said hole is minimized and measurement may be taken substantially without the interference of convection currents, determining selected properties by calculation from said temperature data and the known heating power input, wherein said point-like heat source is used in contact with said material for heating to form substantially spherical isotherms in a perturbed portion of the material to be tested to induce a measurable temperature change at the measuring points, said measuring points at different distances from the heat source being arranged along a straight line passing through the heat source and intersecting the isotherms along their diameter, wherein the measuring points are selected so that the maximum size of the point-like heating element is substantially smaller than the distance between the point-like heating element and the farthest measuring point.

Claim 3

Dependent Claim 19 words

A process as in claim 1, wherein a constant heat flow density is used for generating said spherical isotherms.

Claim 4

Dependent Claim 19 words

A process as in claim 1, wherein the measurements are performed at least at two consecutive points of time.

Claim 5

Dependent Claim 17 words

A process as claimed in claim 1, wherein measurements are performed at three or more measuring points.

Claim 6

Dependent Claim 17 words

A process as claimed in claim 1, wherein measurements are performed for a maximum of 10 hours.

Claim 7

Dependent Claim 41 words

A process as claimed in claim 1, wherein the measurements are performed at points substantially in a line which extends from the point-like heat source along the length of said hole to the entry point of said hole into said material.

Claim 8

Dependent Claim 68 words

A process as claimed in claim 1, wherein measurements are performed at points disposed in a line along the length of said hole, the point-like heat source being positioned between each of said opposite hole ends and measurement being performed at points between said source and one of said ends of said hole and at points between said source and the other of said ends of said hole.

Claim 9

Dependent Claim 39 words

A process as in claim 7, wherein said points are disposed at symmetrical positions with respect to said point-like heat source and wherein the temperature of a reference point is measured, said point being outside the perturbated temperature field.

Claim 10

Dependent Claim 136 words

A measuring probe for the simultaneous in situ determination of thermophysical properties, primarily for determination of the thermal conductivity and thermal diffusivity in a large volume of a solid stationary material, comprising a rod-like body made of poorly heat conductive material, a heating element formed as a point-like heat source to form substantially spherical isotherms, and a plurality of measurement elements, substantially for measuring a thermal characteristic of said solid stationary material, disposed at points along the length of said rod-like body, the maximum size of said heating element being substantially smaller than the distance between the heating element and the farthest measurement element, said rod-like body together with said heat source and said measurement elements being configured for insertion into intimate continuous physical contact with a sidewall of a borewall in said solid stationary material.

Claim 11

Dependent Claim 136 words

A measuring probe for the simultaneous in situ determination of thermophysical properties, primarily for determination of the thermal conductivity and thermal diffusivity in a large volume of a solid stationary material, comprising a rod-like body made of poorly heat conductive material, a heating element formed as a point-like heat source to form substantially spherical isotherms, and a plurality of measurement elements, substantially for measuring a thermal characteristic of said solid stationary material, disposed at points along the length of said rod-like body, the maximum size of said heating element being substantially smaller than the distance between the heating element and the farthest measurement element, said rod-like body together with said heat source and said measurement elements being configured for insertion into intimate continuous physical contact with a sidewall of a borewall in said solid stationary material.

Claim 12

Dependent Claim 38 words

A probe as claimed in claim 9, wherein the heating element is mounted with an expandable elastic ring made of highly heat conductive material producing a sealing engagement with said borehole wall preventing convective currents in said borehole.

Claim 13

Dependent Claim 37 words

A probe as in claim 9, wherein the measuring points are arranged in a line which extends from said heat source along the length of said hole to the entry point of said hole into said material.

Claim 14

Dependent Claim 18 words

A probe as in claim 9, wherein a reference element is positioned at one end of the probe.

Claim 15

Dependent Claim 14 words

A probe as in claim 12, wherein the measurement elements are surface temperature sensors.

Claim 16

Dependent Claim 13 words

A probe as in claim 13, wherein the surface temperature sensors are thermocouples.

Claim 17

Dependent Claim 17 words

A probe as in claim 14, wherein the reference element is a cold junction of said thermocouples.

Claim 18

Dependent Claim 19 words

A probe as in claim 14, wherein at least a portion of said measurement elements are connected in series.

Claim 19

Dependent Claim 21 words

A probe as in claim 9, further comprising means to control said measurement elements, said reference element and said point-like source.

Claim 20

Dependent Claim 21 words

A probe as in claim 9, further comprising means to evaluate the output of said measurement elements and said reference element.

Claim 21

Dependent Claim 161 words

A measuring probe for the simultaneous in-situ determination of thermophysical properties, primarily for determination of the thermal conductivity and thermal diffusivity in a large volume of a solid stationary material, comprising a rod-like body made of poorly heat conductive material, a heating element formed as a point-like heat source for generating substantially spherical isotherms in said solid stationary material, and a plurality of measurement elements, substantially for measuring a thermal characteristic, disposed at points along the length of said rod-like body, the maximum size of said heating element being smaller at least by one order of magnitude, than the distance between the heating element and the farthest measurement element, said rod-like body together with said heat source and said measurement elements being configured for insertion into thermal and physical contact with a sidewall of a borehole, said measuring points being arranged on opposite sides of said heating element and wherein a reference element is positioned at one end of the probe.

Claim 22

Dependent Claim 161 words

A measuring probe for the simultaneous in-situ determination of thermophysical properties, primarily for determination of the thermal conductivity and thermal diffusivity in a large volume of a solid stationary material, comprising a rod-like body made of poorly heat conductive material, a heating element formed as a point-like heat source for generating substantially spherical isotherms in said solid stationary material, and a plurality of measurement elements, substantially for measuring a thermal characteristic, disposed at points along the length of said rod-like body, the maximum size of said heating element being smaller at least by one order of magnitude, than the distance between the heating element and the farthest measurement element, said rod-like body together with said heat source and said measurement elements being configured for insertion into thermal and physical contact with a sidewall of a borehole, said measuring points being arranged on opposite sides of said heating element and wherein a reference element is positioned at one end of the probe.

Claim 23

Dependent Claim 33 words

A probe as in claim 19, wherein said measurement elements occur in pairs at opposite sides of said heating element and each element of each pair is arranged equidistant from the heat source.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-06-11	1993-12-11	1994-06-12	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-06-11	1997-12-11	1998-06-12	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-06-11	2001-12-11	2002-06-12	$7700.00	Window Closed / Lapsed

Process and apparatus for the determination of thermo-physical properties

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