Abstract: A method and apparatus for determining the junction-to-case thermal resistance, .theta..sub.jc, of a solid-state hybrid circuit element 38. First, the temperature coefficient, T.sub.c, of the voltage across the junction is determined with a small calibration current flowing through the junction. Digital multimeters 12 and 28 are used to measure the junction voltage and current, respectively. Next, more power is applied and the total power, P.sub.T, dissipated by the hybrid circuit element 38 is determined from values of the applied voltage and current measured with digital multimeters 12 and 14. The case of the hybrid element is kept at a constant temperature by a heat sink arrangement and the junction is allowed to reach thermal equilibrium at the higher power level. Finally, the increase in power to the hybrid element is removed and the change in junction voltage drop, .DELTA.V.sub.BE, between low-power operation and high-power operation is determined using a storage oscilloscope 30.

Abstract: The installation for determining the thermal resistance of a wall comprises a first measuring unit applicable to the inner side, respectively the warm side of the building element, the unit comprising a measuring plate made of heat conducting material having a given thermal resistance of which one face is intended to be applied to the building element and of which the other face is in thermal contact with an adjustable plane heating body. The measuring plate provides by means of thermocouples arranged on either face a reference signal corresponding to the heat flow through the measuring plate to an electronic control and calculating unit. Furthermore a second measuring unit arranged on the outer side or cold side of the building element comprises at least one contact plate made of heat conductor material covering the measured area and connected to the control and circulation unit by at least another thermocouple.

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: Apparatus for testing diamonds for genuineness including a housing, a probe tip mounted in the housing and formed of a conductive material, a voltage stabilizer located in the housing remote from the probe and coupled to the probe tip by conductive material, the voltage stabilizer being operative to provide an output voltage which varies as a function of the temperature of the conductive probe tip, and indicating apparatus operative to provide a sensible output indication of genuineness of a diamond in response to the output voltage from the voltage stabilizer.

Abstract: For use with a sonde adapted to be lowered into a well borehole, the sonde supports a thermal conductivity probe response to well fluid thermal conductivity. In the preferred and illustrated embodiment, a four leg resistor bridge circuit has two temperature-sensitive legs exposed to well fluid. In addition, one such bridge leg is positioned adjacent to a heater dissipating constant heat power. The remaining leg is exposed to ambient well fluid. The bridge incremental voltage varies with the ambient temperature of the well fluid, but such ambient variations are compensated for by the remaining temperature-sensitive leg which causes nulling of ambient temperature changes. The heat transferred to the heated bridge leg determines the incremental voltage and, hence, the conductivity of fluid in the well bore can be measured.

Abstract: A method and apparatus for determining the bulk thermal conductivity of a particular material includes the steps of embedding a thermistor in the material for which the bulk thermal conductivity is to be measured, applying a small current from a constant current source to the thermistor, mathematically determining the temperature of the material, applying a larger current to the thermistor until a steady state thermal condition is obtained, calculating the thermistor resistance, and finally calculating the thermal conductivity of the material according to the formula ##STR1## where I is the large current, R is the thermistor resistance when heated by the larger current, r.sub.1 is the radius of the thermistor glass bead, T.sub.1 is the surface temperature of the glass envelope of the thermistor and T.sub.2 is the homogenous temperature of material whose bulk thermal conductivity is to be measured.

Abstract: An arrangement for measuring the carbonation level of a liquid, useful for controlling the extent of carbonation of a beverage, particularly in a continuous process stream. A portion of the process stream is diverted to flow adjacent to a gas permeable membrane having a diluent gas such as helium or nitrogen flowing on the opposite side thereof. The diluent gas stream absorbs carbon dioxide in proportion to the extent of carbonation of the beverage, and a suitable characteristic, such as thermal conductivity or infrared absorption, of the diluent gas and carbon dioxide mixture is then measured as an indication of the carbonation level of the beverage.

Abstract: This process consists in raising the temperature of a probe immersed in the fluid to a temperature threshold corresponding to an electric resistance (R.sub.1), in measuring at least a second temperature threshold corresponding to a second resistance (R.sub.2, R.sub.3), in measuring the time elapsed between these different thresholds and in calculating a parameter of the fluid linked to the thermal transfer between the probe and the fluid, i.e., the temperature, the velocity, the viscosity, the density, the specific heat or the thermal conductivity.

Abstract: A simulated diamond such as crystalline cubic zirconia, which has optical properties very similar to natural diamond and so is difficult to distinguish optically from natural diamond, is distinguished from natural diamond by measuring its thermal conductivity which is significantly different from the thermal conductivity of natural diamond, by measuring the temperature of a heated probe held against the simulated diamond as an indication of the simulated diamond thermal conductivity. In a preferred embodiment of the present invention, a controlled amount of heat energy is generated at the probe and thereafter, while the probe is held against the simulated diamond, the temperature of the probe is detected as a measure of relative thermal conductivity of the simulated diamond to the natural diamond.

Abstract: A device is provided which simulates heat transfer into a flexible pouch in which food or like product is cooked and sterilized. The simulator is a block of polymeric material having a thickness approximately that of a food pouch and a thermal diffusivity generally equal to or slightly above that of food product. A thermal sensor is disposed centrally within the block of polymer material and is connected to electrical leads extending externally of the retort to apparatus that records temperature change as a function of time. A plurality of simulators are placed at various regions in the retort, and the uniformity of the heat transfer under certain operating conditions is determined by measuring the heating rates of the several simulators. Operating conditions, such as flow rates or location of introduction of water, steam and air are changed until a sufficiently uniform heat transfer environment is achieved.

Abstract: In a thermal radiation measuring arrangement, a thermal radiation detector is located at the focal point of a collecting mirror, upon which incident thermal radiation from a surface, such as a building wall, is directed. The thermal radiation detector may be, for example, a thermopile, and provides an output signal having a magnitude proportional to the amount of thermal radiation which it receives. The temperature detection means detects the temperature of the thermal radiation detector and, for example, may detect the cold junction of the thermopile. In a first operating condition, a signal summing means receives the output signal from the thermal radiation detector and the temperature detection means and provides a third output signal proportional to the sum of these first and second output signals. In a second operating condition, a signal biasing means is connected into the signal summing means.

Abstract: The inside air temperature, the outside air temperature and the temperature of the inside surface of an exterior structure whose `R` value is to be determined and these values are selectively applied to the `R` value apparatus which stores the inside and outside temperatures as voltage analogs and combines them to provide a first difference signal. The inside temperature analog is also applied to a second combination circuit. After the inside and outside temperature analogs are fed to the apparatus and stored therein, then the inside surface temperature of the structure, such as the wall or ceiling, which is being measured, is applied as an analog voltage to the apparatus. The inside structure temperature analog is combined with the inside room temperature analog to provide a second difference signal which is then divided into the first difference signal in an analog divider, a portion of the output being fed directly to a meter calibrated in `R` values.

Abstract: A simulated diamond such as crystalline cubic zirconia, which has optical properties very similar to natural diamond and so is difficult to distinguish optically from natural diamond, is distinguished from natural diamond by measuring its thermal conductivity which is significantly different from the thermal conductivity of natural diamond, by measuring the temperature of a heated probe held against the simulated diamond as an indication of the simulated diamond thermal conductivity. In a preferred embodiment of the present invention, a controlled amount of heat energy is generated at the probe and thereafter, while the probe is held against the simulated diamond, the temperature of the probe is detected as a measure of relative thermal conductivity of the simulated diamond to the natural diamond.

Abstract: The invention relates to a portable, battery-driven device for measuring heat transfer coefficients (k-values). It uses an amplifier (1), which forms the quotient between the inner temperature minus the inner wall temperature on one hand and the inner temperature minus the outer temperature on the other hand. The temperature values of the first-mentioned substraction are obtained by thermal elements (7, 8), which are connected to the device. The difference according to the second one of the substractions is adjustable connected in a feed back circuit of the amplifier (1). The output quantity of the latter is supplied to an instrument (3) graduated in k-value. The thermal element for the measuring of the inner wall temperature can be provided at the tip of a probe (9), and may consequently be conveniently applied to different places of a wall to be investigated.

Abstract: Natural diamonds can be distinguished from simulated diamonds in seconds by merely touching a hand held probe to the gems. The tip of the probe includes a rounded gem contacting head of high thermal conductivity and low thermal mass. The head is preferably of gold-coated copper. It is supported on a high thermal resistivity neck extending from a large spring biased thermal mass. The head supports a thermistor heater element and a thermistor temperature sensing element within an annular space. Pulses of power are cyclically applied to the heater element to produce a predetermined amount of heat flow from the probe through the sample gem. The resulting change in temperature of the contacting head is determined by sensing the change in resistance of the sensing thermistor and weighting that change by the sensed thermistor resistance. The weighting function is carried out by a gain-controlled amplifier.

Abstract: A subseafloor simulator for measuring acoustical and other physical propees of sediments at temperatures and pressures that simulate the real ocean environment. A pressure chamber has a porous piston to exert a required overburden pressure to simulate the weight of the mineral grains. An inlet port allows the fluid pressure inside the pressure chamber to be independently controlled. Acoustic and thermal transducers are mounted on the bottom of the pressure chamber. Electronic equipment is used for the acoustic and thermal measurements and the measurement of sample pressures and temperatures. A circulating thermal bath controls the temperature of the sediment sample and the pressure chamber.