Abstract: A calorimeter that includes a sample cell, a reference cell, a pressure system that applies a variable pressure to the sample cell, and a pressure controller that controls the pressure applied by the pressure system to the sample cell. By applying identical pressure perturbations to both the sample and reference cells over a range of temperatures, the calorimeter can be used to accurately calculate both the thermal coefficient of expansion of various substances, and the volume change of molecules undergoing a structural transition.

Abstract: The invention relates to a method and a device for registering the presence of an ophthalmic moulding consisting of a biocompatible polymeric material, especially an ophthalmic lens, particularly a contact lens, in a package. The invention solves the problem through the use of an IR camera. Packages containing a moulding, especially a contact lens, have a change in their temperature distribution compared with a package without a contact lens. By evaluating the temperature difference, it is possible to determine whether or not there is a contact lens in a package. In particular, by using the detecting method according to the invention, one can determine whether there is a contact lens in the package directly after the filling procedure.

Abstract: A gas-tight container such as a glove box maintains a sample under a controlled atmosphere and has a sample chamber formed in a convex portion thereof. The temperature is controlled in the sample chamber by an externally disposed heater. A detector such as a weight detector is disposed in the gas-tight container and has a sample holder for holding a sample under analysis. The detector is movably supported by a movement mechanism so that the sample holder is movable between a first position at which a sample disposed on the sample holder is disposed within the sample chamber and a second position at which a sample disposed on the sample holder is disposed outside the sample chamber, such that the mounting of a sample on the sample holder may be accomplished while the sample holder is disposed outside the sample chamber and a thermal analysis of the sample may be performed while the sample is disposed inside the sample chamber.

Abstract: A sensor having an active sensing material exposed to the substance to be detected and an active reference material that is shielded from the substance to be detected. Thermocouples having a set of junctions proximate to the active sensing material and another set of junctions to the active reference material for measuring the temperatures at the respective materials. The junctions are connected differentially in that a difference of the two temperatures is measured. A heater is proximate and common to the two materials. Heat pulses may be applied to the materials via the heater and the temperatures are measured. If ambient factors or substances affect the active sensing material, its thermal response will be different than that of the active reference material, and a differential pulse-like indication of temperature will be detected.

Abstract: A method and apparatus for timely and accurate measurement of material parameters are disclosed. A test sensor measures the temperature of a sample of material as it is heated up and/or cooled down. A reference sensor is used to obtain differential temperature measurements as the temperature of the test sample is varied. A differential temperature trace is generated and analyzed in order to determine various characteristics of the material being tested. In one embodiment, the sodium fluoride to aluminum fluoride ratio (NaF:AlF3) and alumina concentration in a Hall bath aluminum smelting operation are determined in order to efficiently control smelting of aluminum metal. In this embodiment, bath temperature and liquidus temperature may be measured and compared in order to determine the amount of superheat of the bath and to prevent the operation of smelters at higher temperatures than necessary.

Abstract: A thermal analyzer includes a processor for processing a thermal analysis signal of a sample obtained by performing high-speed thermal analysis of the sample at an experimental heating rate. The processor includes a peak component calculator for calculating peak components of the thermal analysis signal, an activation energy calculator for calculating activation energy values based on the peak components of the thermal analysis signal, and a heating rate conversion and output device for estimating a second thermal analysis signal that would be obtained under a thermal analysis of the sample conducted at a desired heating rate different from the experimental heating rate based on the experimental heating rate and the activation energy values obtained by the activation energy calculator, the second thermal analysis signal being calculated based on the thermal analysis signal obtained at the experimental heating rate.

Abstract: The invention is directed to a differential analysis method and apparatus wherein a sample and reference are subjected to an externally applied disturbance, such as temperature change, in accord with a prescribed function comprising the sum of a linearly changing part and a periodically changing part, and the measured differential signal is processed into real and imaginary components relating, respectively, to the energy storage and energy loss portions of the signal.

Abstract: The DSC (DTA) signal waveform measured under an experimental heating rate condition is separated into a base line and individual basic peak elements, and the respective activation energies are calculated corresponding to each of basic peak elements separated. A DSC (DTA) signal that should be obtained at an another heating rate is estimated from the data obtained from the experimental heating rate and it is outputted. In this process, the temperature shift caused by heating rate difference is corrected using the values of activation energies obtained.

Abstract: A method and apparatus for performing combined single differential thermal analysis and dynamic mechanical analysis of a sample relative to a reference, using either one reference measurement for a sequence of material measurements--whereby the reference can also be represented by an empty weighing pan--or by the use of a mathematical model which is so determined that it takes the real behavior of the thermal analytical apparatus into account. Reference temperature curves are generated relative to time of an empty furnace or a reference sample contained in the furnace, and temperature curves of a sample to be measured are taken at the exact same location in the furnace. The reference and sample temperature curves are compared to determine the temperature difference.

Abstract: Disclosed is a method for operating a sensor to differentiate between first and second analytes in a sample. The method comprises the steps of determining a input profile for the sensor which will enhance the difference in the output profiles of the sensor as between the first analyte and the second analyte; determining a first analyte output profile as observed when the input profile is applied to the sensor; determining a second analyte output profile as observed when the temperature profile is applied to the sensor; introducing the sensor to the sample while applying the temperature profile to the sensor, thereby obtaining a sample output profile; and evaluating the sample output profile as against the first and second analyte output profiles to thereby determine which of the analytes is present in the sample.

Abstract: A differential scanning microcalorimeter produced on a silicon chip enables microscopic scanning calorimetry measurements of small samples and thin films. The chip may be fabricated using standard CMOS processes. The microcalorimeter includes a reference zone and a sample zone. The reference and sample zones may be at opposite ends of a suspended platform or may reside on separate platforms. An integrated polysilicon heater provides heat to each zone. A thermopile consisting of a succession of thermocouple junctions generates a voltage representing the temperature difference between the reference and sample zones. Temperature differences between the zones provide information about the chemical reactions and phase transitions that occur in a sample placed in the sample zone.

Abstract: A device for use in vehicles with electric or hybrid drive for monitoring the air conditioning of a vehicle based on health and energy consumption readings. The device monitors the operation of the air conditioning to determine when differentials between outside and inside temperature are excessive, and/or inside atmospheric humidity is too low and/or air quality is poor. An occurrence of any of these conditions results in the system suggesting to the driver that he should interrupt travel to the desired destination. In addition, if necessary, the device performs a vehicle range estimate as a function of the selected air conditioning operation.

Abstract: The method of detecting and identifying a substance in a sample requires the sample to be changed from a first temperature to a second temperature, the sample scanned with an instrument for measuring infrared radiation, the temperature difference between the temperature of the substance at the sample's first and second temperatures determined, and the substance identified based on this temperature difference. The infrared method allows for the objective determination of a substance in a sample without the necessity of the labor and time required in conventional methods and is especially suitable for detecting the presence of "stickies" in recycled paper.

Abstract: A method of simultaneously measuring thermal conductivity and heat capacity of a fluid, using a heat conduction calorimeter having a reference fluid in a first cell and a sample fluid in a second cell includes the steps of calibrating the calorimeter using a standard fluid having known thermal conductivity and heat capacity over a range of temperatures and the reference fluid to determine a set of sensitivity parameters, {a.sub.n.sup.ij }, of the calorimeter, wherein the a.sub.n.sup.ij are functions of the calorimeter, temperature and the reference fluid; applying a square wave heat pulse to the calorimeter containing said sample fluid and said reference fluid; measuring the thermal response curve to the square wave heat pulse, wherein the thermal response curve is a function of time, temperature of the measurement, thermal properties of the sample fluid, and thermal properties of the reference fluid; reducing the response curve to a set of discrete characteristic parameters, {p.sub.

Abstract: A hybrid surface mount component inspection system which includes both vision and infrared inspection techniques to determine the presence of surface mount components on a printed wiring board, and the quality of solder joints of surface mount components on printed wiring boards by using data level sensor fusion to combine data from two infrared sensors to obtain emissivity independent thermal signatures of solder joints, and using feature level sensor fusion with active perception to assemble and process inspection information from any number of sensors to determine characteristic feature sets of different defect classes to classify solder defects.

Abstract: A Differential Scanning Calorimeter (DSC) which has constant calorimetric sensitivity over its entire range of operating temperatures from -200.degree. C. to 540.degree. C. The DSC sensor consists of a pair of thin-film Resistance Temperature Detectors (RTDs) which are used to sense the temperature of a sample and the temperature difference between the sample and an inert reference. The RTDs are supplied with an excitation current which varies according to the temperature of the reference to achieve constant calorimetric sensitivity, independent of the operating temperature.

Abstract: The method of detecting and identifying a substance in a sample requires the sample to be changed from a first temperature to a second temperature, the sample scanned with an instrument for measuring infrared radiation, the temperature difference between the temperature of the substance and a reference temperature determined, and the substance identified based on this temperature difference. The infrared method allows for the objective determination of a substance in a sample without the necessity of the labor and time required in conventional methods and is especially suitable for detecting the presence of "stickies" in recycled paper.

Abstract: A catalytic differential gas combustible microcalorimeter sensor for monitoring the exhaust gas conversion for monitoring the exhaust gas conversion efficiency of a catalytic converter. The catalytic calorimetric sensor disclosed includes a sol-gel processed washcoat and sol-processed catalytically active metal particles. Sol-gel processing creates a washcoat with high surface area and controlled porosity which increases the sensitivity, durability, and reproducibility of the resultant sensor.

Abstract: A method and apparatus for performing single differential thermal analysis of a sample relative to a reference, using either one reference measurement for a sequence of material measurements--whereby the reference can also be represented by an empty weighing pan--or by the use of a mathmematical model which is so determined that it takes the real behavior of the thermal analytical apparatus into account. Reference temperature curves are generated relative to time of an empty furnace or a reference sample contained in the furnace, and temperature curves of a sample to be measured are taken at the exact same location in the furnace. The reference and sample temperature curves are compared to determine the temperature difference.

Abstract: A method for measuring the coefficient of thermal conductivity of a solid sample material by: heating a meltable calibration sample having good thermal conductivity to its melting temperature by raising the temperature of an analyzer at a controlled rate and causing heat to flow through a path having a thermal resistance to the calibration sample, the heating being performed one time with the solid sample material interposed in the path so that heat flows through the path and through the solid sample material, and one time with the solid sample material removed so that heat flows only through the path; deriving thermal analysis curves each representing a relation between heat flow to the calibration sample and the controlled rate at which the analyzer temperature is raised, during melting of the calibration sample in respective performances of the heating step; and determining the coefficient of thermal conductivity of the solid sample material based on the solid sample material thickness and a characteristic

Abstract: In order to carry out thermal analysis under various kinds of atmospheres, there is provided an apparatus for thermal analysis containing a sample chamber having a portion for a sample and a signal detection chamber provided with a signal detection member, the signal detection chamber having an inlet port for a purging gas, the sample chamber and the signal detection chamber being connected through a purging gas passage, and the sample chamber being provided with an inlet port for an atmosphere gas and also with an outlet port for the atmosphere gas and the purging gas.

Abstract: The invention is directed to a differential analysis method and apparatus wherein a sample and reference are subjected to an externally applied disturbance, such as temperature change, in accord with a prescribed function comprising the sum of a linearly changing part and a periodically changing part, and the measured differential signal is processed into real and imaginary components relating, respectively, to the energy storage and energy loss portions of the signal.

Abstract: A heat detector uses a single comparator operating in conjunction with a dynamically changing thermal reference that ensures quick response to rapid rates of thermal change and a fixed threshold that indicates an ambient temperature exceeds a threshold temperature. The inputs of the comparator receive different ones of the output signals of two thermal sensors. One thermal sensor responds nearly instantaneously to changes in ambient thermal conditions. The other thermal sensor is mounted on a printed circuit board operating as a heat sink and responds more slowly to changes in ambient thermal conditions. The difference between the thermal sensor output signals is zero at a lower ambient temperature when the rate of thermal change exceeds a preset amount and at a higher ambient temperature when the rate of thermal change is relatively slow.

Abstract: The present invention is a mechanical cooling system, for use with thermal analysis instruments such as differential scanning calorimeters, which interposes a gaseous heat transfer path between the heat exchanger or evaporator cooling the differential scanning calorimeter cell and the differential scanning calorimeter cell. This configuration improves the performance of the thermal analysis system by reducing noise in the heat flow signal otherwise resulting from evaporation of the refrigerant in the heat exchanger. The mechanical cooling system is attached to the thermal analysis instrument by an arrangement providing for minimum direct physical contact between the mechanical cooling system and the thermal analysis instrument.

Abstract: The present invention relates to analytical methods for determining the composition of a material that undergoes a transition as a function of a driving variable. As applied to thermogravimetric analysis (TGA), a first preferred embodiment comprises (1) decreasing the heating rate when deviations from a baseline signal are detected; (2) establishing a minimum heating rate; (3) forcing the heating rate to a predetermined maximum whenever the rate of change of the weight change with respect to the temperature falls below a predetermined value; and (4) adjusting the heating rate according to the rate of change of the weight of the sample to track a predetermined rate of change of the weight of the sample.

Abstract: The present invention relates to an apparatus which is designed to employ thermal stimulated processes for analyzing relaxation spectra and resonances in materials. The invention is characterized in that at least two coupled excitation fields are applied to the sample of material analyzed along with a programmed temperature variation, to deconvolute during the thermally stimulated recovery stage the global deformation resulting from the excitation stage. In other words, this invention is designed to obtain one by one the individual and elementary relaxation motions responsible for the global deformation, whether these elementary internal motions have a mechanical, electrical or magnetic origin. Moreover, the relaxation spectra for the motions resulting from the coupling between mechanical, electrical and/or electromagnetical excitations are obtained at the same time and are interrelated.

Abstract: The present invention relates to differential analytical techniques for determining the composition, phase, structure, identification or other properties of a material that undergoes a transition as function of a driving variable. As applied to differential scanning calorimetric analysis (DSC), the preferred embodiment comprises: (1) heating a sample of the material with a linear temperature ramp that is modulated with a sinusoidal heating rate oscillation; and (2) deconvoluting the resultant heat flow signal into rapidly reversible and non-rapidly reversible components.

Abstract: The present invention is a thermogravimetric instrument having a ceramic sample support and a ceramic balance beam. The ceramic platform is rigidly attached to the hot end of the ceramic balance beam. An inert metal liner is press fitted into the ceramic sample platform. In a preferred embodiment, a thermocouple is directly attached to the inert metal liner. The thermocouple wires are routed through the length of the ceramic balance beam and are attached to the cold end of the ceramic balance beam with adhesive. The inert metal liner could be fabricated from platinum or from platinum alloys.

Abstract: The calorimeter comprises an external accommodating head (23) with two cavities (26, 27) which are capable of receiving a measurement cell (29), in which the specimen to be examined is inserted, and a reference cell (31); the cells (29, 31) are surrounded by a thermoresistor (229), the variation of the resistance of which is determined by a temperature variation, and a heater (129). The two cavities (26, 27) are closed by covers (35, 37) traversed by tubular stems (47-49) capable of supporting the cells (29, 31) for the insertion, into one of them, of a specimen contained in a tubular container (53), which is immersed in a chamber (29A) in which a fluid having high thermal conductivity is present; said cavities (26, 27) are reached by conduits (41, 43; 45) so as to be subjected to vacuum or to controlled pressure using replaceable gases (air, hydrogen, etc.).

Abstract: A high resolution digital thermometer capable of measuring temperature differences on the order of several micro-degrees centigrade. The device includes a bridge circuit having two thermistors in series. An output of the bridge circuit feeds a signal to an analog-to-digital convertor via a high gain amplifier. A computer maintains the balance of the bridge circuit to avoid a situation wherein the range of the analog-to-digital convertor would be exceeded.

Abstract: A differential thermal analysis sensor consisting of two low-impedance differential thermopiles. Each thermopile consists of a series of thermocouples joined in series, with the measuring junctions of the thermocouples arranged around a uniform temperature measuring region, and the thermoelectric reference junctions of the thermocouples arranged around a uniform temperature thermoelectric reference region. The differential thermal analysis sensor can be used for single-sample heat flux differential thermal analysis measurements, dual-sample heat flux differential thermal analysis measurements, or power compensation differential thermal analysis measurements.

Abstract: The present invention relates to an apparatus which is designed to employ thermal stimulated processes for analyzing relaxation spectra and resonances in materials. The invention is characterized in that at least two coupled excitation fields are applied to the sample of material analyzed along with a programmed temperature variation, to deconvolute during the thermally stimulated recovery stage the global deformation resulting from the excitation stage. In other words, this invention is designed to obtain one by one the individual and elementary relaxation motions responsible for the global deformation, whether these elementary internal motions have a mechanical, electrical or magnetic origin. Moreover, the relaxation spectra for the motions resulting from the coupling between mechanical, electrical and/or electromagnetical excitations are obtained at the same time and are interrelated.

Abstract: A method and apparatus for simultaneous differential scanning calorimetry and microdielectrometry is disclosed. The apparatus includes a sample cell containing a sensor for measuring the dielectric and thermal properties of the sample. The method applies a voltage to a material while heating the material over a temperature range and then simultaneously measuring the current gain of the material, the temperature of the material and the energy input to the material.

Abstract: A method and an apparatus for sorting particulate solids material. The material is subjected to a microwave field and absorbs energy to an extent depending upon the dielectric properties of the individual particles. The absorbed energy heats the particles, and pyrodetectors detect the heat radiation. Detector output signals control pressurized air jets to remove particles from the waste material which are detected to be colder than the remainder of the bulk.

Abstract: A method for determining the relative humidity in an interior space without using a special humidity sensor, the method including passing a flow of air of known temperature and humidity through the cooling coil of a known air conditioning system for a pre-determined period of time. The temperature of the air exiting from the cooling coil after the pre-determined period of time is measured. A reference temperature differential is determined by subtracting the exiting temperature from the known temperature of the entering air. A flow of air for which it is desired to know the relative humidity is then passed through the cooling coil for the same pre-determined period of time. The temperature of the air entering the cooling coil and exiting from the cooling coil at the end of this pre-determined period of time is determined. The exit temperature is subtracted from the entering temperature to provide the temperature differential for the air of unknown relative humidity.

Abstract: This monitoring invention is an improvement over the ozone (O.sub.3) and hydrogen peroxide (H.sub.2 O.sub.2) monitoring systems that are now commercially used.The manner in which this monitor measures the gas, or a gas dissolved in a liquid, is by measuring the heat energy that is released when the material to be measured is catalyzed. The detector measures the heat produced when, for example, ozone is reduced to oxygen or the hydrogen peroxide is reduced to oxygen and water by a catalytic action. This heat energy is collected and measured. The higher the temperature, the higher the concentration.

Abstract: The present invention relates to analytical methods for determining the composition of a material that undergoes a transition as a function of a driving variable. As applied to thermogravimetric analysis (TGA), a first preferred embodiment comprises (1) decreasing the heating rate when deviations from a baseline signal are detected; (2) establishing a minimum heating rate; (3) forcing the heating rate to a predetermined maximum whenever the rate of change of the weight change with respect to the temperature falls below a predetermined value; and (4) adjusting the heating rate according to the rate of change of the weight of the sample to track a predetermined rate of change of the weight of the sample.

Abstract: There is provided a differential thermal analysis calorimeter for performing thermal hazard testing procedures which can be utilized as an ancillary plug-in device with commercial thermal analysis data acquisition systems. Simultaneous measurement of heat flow of sample reactants and direct measurement of sample pressure is provided during a reaction within a substantially hollow furnace enclosure defining a heated zone having a heated top plate. A pair of longitudinally elongated heat conductive sample and reference tubes having upper and lower ends are each connected to the top plate adjacent their respective upper ends. The tubes depend downwardly from the top plate within the hollow furnace enclosure, and are heated by the heating means, whereby heat is conducted to the lower end of each tube longitudinally therealong. A pressure transducer is connected adjacent the upper end of the sample tube for directly measuring the pressure in the sample tube within the heated zone of the furnace.

Abstract: The present invention relates to the use of thermal stimulated processes for analyzing relaxation spectra and resonances in materials. The process is characterized in that at least two coupled excitation fields are applied to the sample of material analyzed along with a programmed temperature variation, with the objective to deconvolute during the thermally stimulated recovery stage the global deformation resulting from the excitation stage, i.e. obtain one by one the individual and elementary relaxation motions responsible for the global deformation, whether these elementary internal motions be of mechanical, electrical or magnetic origin. The process is characterized in the fact that the relaxation spectra for the motions resulting from the coupling between mechanical and electrical (and/or electromagnetical) excitations are obtained at the same time and are inter-related.

Abstract: A method and apparatus measures thermal conductivity of a material effected by measuring a change in the temperature of the material in contact with a heat source maintained at a predetermined temperature. A temperature change characteristic is obtained from the result of the temperature measurement, and the thermal conductivity is obtained by comparison of the temperature change characteristic and unsteady heat transfer characteristics of solid bodies previously determined in consideration of the heat transfer resistance of the interfaces. The present invention is suitable for the measurement of extensive materials, metallic materials to heat insulating materials, specifically suitable for the measurement of materials of high thermal conductivity and heterogeneous or anisotropic and is capable of accurately measuring the thermal conductivity without any special consideration on the interface heat transfer resistance at the measurement stage.

Abstract: A method and the instrument associated therewith for determining the Curie points of ferromagnetic materials which display no significant abrupt change in heat absorption around the Curie points thereof by means of a conventional thermal analyzer with externally added facilities to provided an external magnetic field. The abrupt change of heat absorption of the ferromagnetic materials is increased by adding the external magnetic field to increase the magnetic anisotropy energy thereof and to strengthen the spontaneous magnetization thereof.

Abstract: Apparatus and process for determining the emissivity of a test specimen including an integrated sphere having two concentric walls with a coolant circulating therebetween, and disposed within a chamber which may be under ambient, vacuum or inert gas conditions. A reference sample is disposed within the sphere with a monochromatic light source in optical alignment therewith. A pyrometer is in optical alignment with the test sample for obtaining continuous test sample temperature measurements during a test. An arcuate slit port is provided through the spaced concentric walls of the integrating sphere with a movable monochromatic light source extending through and movable along the arcuate slit port. A detector system extends through the integrating sphere for continuously detecting an integrated signal indicative of all radiation within its field of view, as a function of the emissivity of the test specimen at various temperatures and various angle position of the monochromatic light source.

Abstract: A circuit for measuring temperature differentials in a calorimeter is disclosed. The temperature differential between the reference element and sample element containing a radioactive material is measured via a wheatstone bridge arrangement of thermistors. The bridge is driven with an alternating current on a pulsed basis to maintain the thermal floor of the calorimeter at a low reference value. A lock-in amplifier connected to the bridge phase locks a signal from the bridge to the input pulsed AC signal to provide a DC voltage. The DC voltage is sampled over time and provided to a digital computer. The digital computer, using curve fitting algorithms, will derive a function for the sample data. From the function, an equilibrium value for the temperature may be calculated.

Abstract: A sensor comprising a heating element and a temperature detecting element used to measure a temperature of the heating element are both held out of contact with each other within a sensor protecting tube. For fluid exhibiting slow changes in its state as time elapses, a fluid state is measured on the basis of a differential temperature between temperatures prior to and during heating of the heating element. For the fluid exhibiting rapid changes in its state as time elapses, the sensor is caused to generate heat while the temperature of this sensor is measured, and a separate temperature measuring sensor measures the temperature of the fluid. The fluid state is determined on the basis of the differential temperature between the temperatures of the sensor and the temperatures of the fluid.

Abstract: A brake fluid tester for measuring the quality of brake fluid, comprising means for measuring the conductivity of the brake fluid, preferably comprising a plurality of comparators for comparing the resistance of the brake fluid to a plurality of reference, resistances. The device further comprises indicating means, preferably light emitting diodes, responsive to the measuring means for indicating the quality of the brake fluid based upon its measured conductivity. An increasing number of diodes are illuminated as the conductivity of the brake fluid increases, providing a positive indication when the device is working and providing an easy to interpret display of the test results. The diodes are preferably activated at preselected levels of conductivity, corresponding to preselected levels of moisture contamination.

Abstract: In a frost and dew sensor composed of two thermosensitive resistors, a power source and an arithmetic circuit, frost or dew is detected from the change of a differential temperature between the two thermosensitive resistors as two different currents from the power source are supplied to the respective thermosensitive resistors. In an alternative form, the sensor has a single thermosensitive resistor, which is energized as two different currents are alternately supplied from the power source so that frost or dew is detected by comparison of the time-lags between the two outputs from the thermosensitive resistor.

Abstract: In a frost and dew sensor composed of two thermosensitive resistors, a power source and an arithmetic circuit, frost or dew is detected from the change of a differential temperature between the two thermosensitive resistors as two different currents from the power source are supplied to the respective thermosensitive resistors. In an alternative form, the sensor has a single thermosensitive resistor, which is energized as two different currents are alternately supplied from the power source so that frost or dew is detected by comparison of the time-lags between the two outputs from the thermosensitive resistor.

Abstract: Apparatus for testing material for thermally insulating pipes comprises a closed loop of pipe in a square configuration with an electric heater mounted coaxially within it. Thermocouples are attached to the pipe from the inside, and they and the heater are accessible via removable caps at the corners of the square. The pipe is suspended from a support framework by rods of low thermal conductivity welded to the inside corners of the square. The insulating material is applied to the pipe, and additional thermocouples fixed to its exterior. The heater is energized and the steady-state temperatures inside and outside the insulating material are measured. The configuration of the apparatus enables corrections for non-uniformity of heat loss and leakage through the rods to be readily made. Thus thermal conductivity values accurately representative of the performance of the insulating material in actual operation can be derived from the temperature measurements.

Abstract: A method for determining the level of heavier particulate waste material in a storage tank of liquid. The method comprises mounting a heated sensor below an unheated or reference sensor so that the reference sensor is influenced under some circumstances by the heater, but is insulated therefrom when the heated sensor is embedded in the particulate material. The invention includes the apparatus for accomplishing the method.

Abstract: A sequence of temporally-spaced radiant energy pulses are applied to the front surface of the sample and the heat rise caused by each thermal pulse is measured at the second surface using a suitable thermocouple or infrared sensor. The temperature rise data for each pulse is digitized and stored in a two-state memory device such as a random access memory. The data from each successive pulse is coadded and statistically processed by averaging to derive a set of favored values indicative of the temperature of the sample as a function of time. The favored values data is further processed using a least squares curve fitting algorithm to determine a numerical value indicative of the diffusivity of the sample.