Abstract: An apparatus for testing the quench-cooling properties of a liquid quenchant includes a thermistor that is adapted to be immersed in the liquid to be tested. An electrical potential is applied across the thermistor, which is contained in one leg of an electrical bridge circuit. A first timer controls the duration of time during which the voltage is applied to the bridge circuit. A voltmeter is connected across the bridge circuit for indicating changes in the bridge balance due to changes in the resistance of the thermistor. The thermistor changes resistance in accordance with the thermal conductivity of the liquid in which it is immersed. Therefore, the quenchant properties of the liquid being tested are determinable by comparing the voltage output of the bridge when the thermistor is immersed in the test liquid with at least one reference voltage output obtained by immersing the thermistor in a reference liquid quenchant. Each test is conducted for the same amount of time, which is controlled by the timer.

Abstract: Heat fluxmeter incorporating a row of thermistors, whose electrical resistance varies significantly with the temperature and which are arranged on the outer surface of the container for accurately measuring the temperature thereof. The range of temperatures in the vicinity of the container is determined by means of a second row of thermistors. It is possible to deduce therefrom the heat flux leaving the container, i.e. the power emitted by the calorigenic material contained therein. The considerable sensitivity of this meter makes it possible to use it without excessively disturbing the thermal equilibrium so that the measurement can be carried out in a very short time.

Abstract: A method and apparatus are disclosed which relate to measuring the quantity and thermal insulating value of fibrous material as it is delivered from a source to another location. A feeder mechanism is provided for delivering the material such as insulation to housing from which it is dispensed ultimately to some cavity such as wall space or surface. The housing includes rotary vanes which divide the housing into a number of separate chambers. A measuring system provided with electronic circuitry and acoustical apparatus delivers a controlled acoustical signal to the chamber containing the fibrous material. A sensor senses acoustical signal generated by a source but altered by the fibrous material within the chamber. Signals corresponding to the source signal and the sensed signal are both fed to a comparator which in turn emits a signal proportional to the volume and density, or thermal insulating value of material contained in the chamber.

Abstract: There is obtained a continuous rapidly responding and controllable measurement of the quenching intensity of quenching baths. A test body is inserted into the bath and a controlled heating is applied to a portion of the surface of the test body raising the temperature of that portion of the test body surface to a constant temperature of 50.degree. to 700.degree. C., especially 150.degree. to 400.degree. C. higher than the temperature of the bath. The heat energy required to maintain this temperature constant is used as a measure of the quenching intensity of the bath.

Abstract: A method and apparatus for determination the thermal conduction coefficient and the heat capacity of materials. The method comprises the measurements of heat flux across the sample and the momentary temperature difference between both surfaces of the sample perpendicular to the direction of heat flux during continuous change of the temperature of one of sample surfaces. The values of thermal conduction coefficient, heat capacity and thermal diffusivity are determined on the basis of an equation which defines their dependence on measured heat flux across the sample, temperature difference between the sample surfaces and the rate of the change of the temperature of one sample surface. The apparatus for measuring thermal conductivity and heat capacity contains a heater equipped with a temperature sensor of a thickness less than 1 mm, placed between two samples, one of them being the sample of material tested of a thickness less than 10 mm.

Abstract: To measure the heat transfer coefficient of a sample, an element with temperature sensitive optical properties is placed in contact or implanted in the sample. The element is heated or cooled. The temperature difference between the element and the unheated sample and the rate of heating or cooling indicate the heat transfer coefficient of the sample. In one embodiment, the element is heated or cooled at a constant rate. The heat transfer coefficient of the sample is then inversely related to the difference in temperature between the element and the unheated sample. Alternatively, the element may be heated or cooled at such a rate that the temperature difference between the element and the unheated sample remains substantially constant. The heat transfer coefficient of the sample then varies directly with the rate of heating or cooling. The heat transfer coefficient of a sample is a measure of its composition and other physical properties.

Abstract: The present invention relates to a method and apparatus used to determine the heat flux through a portion of a surface of a heat exchanger tube, using heat flux sensor means that is installed on the inner wall of the heat exchanger tube and send a signal to a connected heat flux meter.

Abstract: A heater block assembly for a jet fuel thermal oxidation test apparatus has back and front plates with a test plate clamped therebetween. The test plate has a flat surface which faces the front plate, while the front plate has a raised ledge with a channel formed therein which faces the flat surface of the test plate. Also, inlet and outlet openings to opposite ends of the channel are formed through the front plate. When the back and front plates are clamped together with the test plate therebetween, the flat surface of the test plate and the channel in the front plate together define a fuel sample flow passage. Thus, the fuel sample undergoing test is pumped through the inlet on the front plate into the flow passage where it flows along and in contact with the flat surface and then out through the outlet on the front plate.

Abstract: A heat energy measuring system which directs radiation through a sample of a combustible fluid and detects the absorbance of at least one combustible component of the combustible fluid at a selected spectral line, there being at least one spectral line for each combustible component to be examined in the fluid. The system also combines at least one heat energy proportionality factor with the absorbance at each spectral line and sums these combinations to determine the heat energy of the fluid. Where the components to be examined are functional groups, the system measures more generally a physical property of a fluid dependent on the physical characteristics of and the quantity of those functional groups in the fluid.

Abstract: Disclosed is a method for measuring changes in a physical property of a liquid or semisolid material which comprises placing a thin metal wire in the material; passing an electric current through the thin metal wire in such a way that the temperature difference between the material and the thin metal wire is kept constant; measuring the intensity of the electric current; and calculating the heat transfer coefficient at the surface of the thin metal wire on the basis of the measured intensity of the electric current and thereby detecting changes in a physical property of the material. This method makes it possible to detect, for example, changes in the coefficient of kinematic viscosity of a food having the form of a gel or changes in the condition of thrombus formation in a blood vessel.

Abstract: A method for the determination of the heat transfer coefficient on a heat transferring surface, including the steps of arranging a layer for measuring the surface temperature and heat flux on the heat transferring surface so that the layer can change the original temperature and heat flux to a negligible extent only, providing for the slight and properly slow changeability of the surface heat flux density within a cycle time which is by several orders of magnitude longer than the time constants of the heat flux measuring layer and of the heat transferring boundary layer, by using a supplementary heating element and performing a practically unlimited number of measuring cycles, using the steps of deflecting the surface heat flux density and temperature relative to the condition in which no measurement takes place. The time-functions of the changes of the surface temperature .DELTA.T and of the surface heat flux density .DELTA.

Abstract: A method of evaluating the cooling performance of a heat treatment agent, wherein a sensor (1), in which the relationship between the electric resistance value and the temperature is known, is immersed in the heat treatment agent, a voltage and a current are applied to the sensor, the voltage and the current are made variable to change the temperature of the sensor, and a predetermined relationship is sought between the temperature and the dissipated heat value on the basis of the change in temperature.

Abstract: A method for accurate, on site heat flow measurement through a substrate surface using surface mounted heat flow sensors and an apparatus for on site calibration of surface mounted heat flow sensors are presented. The method comprises mounting on the substrate surface a heat flow sensor which is calibrated to establish the relationship between heat flow through the surface and the resultant induced voltage in the sensor under the convective and radiative heat transfer environmental conditions of the surface, measuring the voltage output induced in the sensor by heat flow through the surface, and converting the voltage output to a quantitative heat flow on the basis of the calibration of the sensor. The apparatus of the invention permits the calibration of the sensors under convective and radiative heat transfer environmental conditions which substantially duplicate those of the experimental substrate.

Abstract: In accordance with a preferred embodiment, calorimetric properties of a microwave heatable work load are obtained while the load is being heated by producing electrical signals indicative of the net applied microwave power and the temperature of the material, and using the signals to produce a signal indicative of the net energy, or the specific heat, or the reflection coefficient of the work load as a function of its temperature.

Abstract: A device and process for determining the vacuum dewar heat load at cryogenic temperatures by a test made at room temperature are described. The test device comprises a heat source and integral temperature sensor mounted on a probe tip. The heat load of a test dewar at a desired test temperature (e.g. 77K) may be determined by measuring the heat load of the dewar under test at a more suitable test temperature (e.g. room temperature) and multiplying that room temperature heat load by a correlation factor. This correlation factor is empirically determined, and is dependent on the design of the test device and dewar, and the desired and actual test temperatures.

Abstract: The quality of heat insulation materials is tested and/or compared in a portable structure in which two heat insulation materials are subjected simultaneously to heat flow from a single common metal-clad heating element and the quantity of heat flow through said material is measured and compared. In one case the portable structure has two conveniently accessible cavities within which equal amounts of such insulation, in flat form, may be placed in contact with corresponding opposite sides of a single common metal-clad planar heat source. In a modification of the invention two tubular insulating materials each of the form and type for insulating pipe, is placed around a metal-clad round heating element and the amount of heat flowing from the heating element and through a corresponding one of said materials is measured and compared using individual thermopiles secured to the outer surface of each material.

Abstract: A method and apparatus for evaluting the performance of a heat exchanger are described. Water is supplied to the heat exchanger at a known mass flow rate and temperature. The water is directed to traverse a flow path of the heat exchanger. The water is then heated and redirected into another flow path of the heat exchanger in heat exchange relation with the first flow path. The temperature change of the water over a flow path is measured to determine the performance of the heat exchange. The water flow rate and incoming water temperature may be fixed to make a single discharge temperature measurement sufficient to calculate heat exchager performance.

Abstract: A granular superconducting thin film bolometer made by anodizing a thin film of such materials as niobium nitride to form a thin granular film separated by and covered with the anodized oxide. The bolometer is cooled to its superconducting state and electrically connected to a biasing and detecting network. Its temporal response is better than 1 ns.

Abstract: A closed loop control apparatus utilizes a cooling effect sensor to measure the cooling capacity of a fluid in a supply conduit connected to one or more thermal loads. The sensor includes an electrical heater that is regulated to heat a sampled portion of the cooling fluid at a known rate, and a temperature sensor positioned downstream of the heater to measure the temperature of the heated fluid and thereby determine the cooling effect or capacity of the fluid. A control signal developed by the temperature sensor is fed back to a flow modulating valve that adjusts the flow of cooling fluid to the thermal loads.

Abstract: A method and apparatus for determining the cooling characteristics of a quenching medium includes a temperature probe having a predetermined thermal mass and conductivity and a temperature sensor affixed to the probe. The probe and sensor are heated to a predetermined temperature and immersed in the quenching medium. The output of the temperature sensor is applied to a microcomputer that has been programmed to monitor the quench rate and to determine whether the quench rate is within predetermined limits at predetermined temperatures.

Abstract: A method, for the determination of moisture content of fibrous and granular materials, comprising bringing a sensitive element in contact with a fibrous or granular material under study. During the time of contact of the sensitive element with the material under study the sensitive element is subjected to preliminary pulse heating to between 40.degree. and 90.degree. C., with subsequent main pulse heating to between 90.degree. and 140.degree. C. The moisture content of the material under study is evaluated by the time for the main heating of the sensitive element. An apparatus for carrying out the above method comprises main and auxiliary measuring bridge circuits having arms in which are inserted resistors and a sensitive element comprising a pulse heat emitter which forms a common arm of both bridge circuits. A selector switch is inserted in the common arm of the bridge circuits.

Abstract: A test apparatus is provided for testing the heat transfer resistance of a tube, such as a tube of a heat exchanger, the apparatus including a heating means, such as a block of metal surrounding and engaging a part of the tube, with an electric heater for heating the block, the block including at least two termistors at different distances from the tube to measure heat flux. A pump causes water to flow through the tube, and a thermistor measures the water temperature. A flow meter and a pressure drop sensor for sensing the drop in pressure across the block are also provided. The measuring devices other than the flow meter provide, preferrably, analog output signals, which are converted and supplied to a computer for computation of total heat transfer resistance, convective heat transfer resistance, conductive heat transfer resistance of the tube and friction factor.

Abstract: A system for determining whether a bar of precious metal has a purity of composition which is within a given range of variance. Heat is induced in one end of the bar using an induction heater powered by a high frequency power source, and the time vs. temperature response at the other end of the bar is monitored.

Abstract: The composition of a sample is determined with reference to a recorded standard using the same heater and sensor as that used to record the standard, by testing the sample only when its temperature has reached an equilibrium, and by compensating for differences in environment and starting temperature; accurate heater control is insured by maintaining a constant voltage across a series circuit consisting of a heater and a resistance load equal to the resistance of the heater; the heater is pulsed in an initial test sequence to heat the system to above ambient so that heat losses to the environment are substantially the same from test to test; a dynamic insulation system prevents heat loss from the sample under test; an improved test based on the sensed temperature of the sample immediately after the heater is turned off detects the presence of tungsten forgeries; a compensated infrared sensor eliminates the need for a direct contact temperature sensor; and tests are provided for determining various physical ch