Abstract:
An optical temperature sensor has an outer probe with a sapphire element at its forward end within a stagnation chamber through which hot gas flows and heats a thermally-emissive coating on the element. A lens focusses radiation emitted by the coating onto one end of a fibre-optic cable that extends within the rear of the probe. A gas passage along the probe enables cooling gas to flow from an inlet at the rear end, around the fibre optic cable, lens and through an outlet rearwardly of a transparent thermal barrier which protects the sapphire element from the cooling gas.
Abstract:
A precious metal blackbody radiator fired on a silica or sapphire fiber is disclosed for use in an optical fiber thermometer. The fiber can be coated or uncoated. If a coated fiber is used, the fiber can be a silica or sapphire fiber, protected with an outer metallic coating, such as platinum, which may be electroplated over a thin electrically conductive film coated on the fiber. The blackbody radiator may be mounted on a first end of the fiber, and the fiber may have a second end terminating at a receptor apparatus. The blackbody may comprise semisolid platinum paste placed on a coated or uncoated fiber, dried, and fired over a flame or in a high-temperature furnace. The firing step causes strong adhesion of the blackbody to the fiber.
Abstract:
A technique of measuring very high temperatures by positioning a blackbody sensor in thermal communication with an environment or object whose temperature is to be measured, communicating infrared emissions having an energy level proportional to such temperature from the sensor to an infrared absorber positioned a distance away from the sensor where the ambient temperature is significantly reduced, and then optically measuring the temperature of the absorber by a technique that uses visible or near visible optical radiation, such as one using a luminescent sensor. The measured temperature of the absorber is proportional to that of the blackbody sensor.
Abstract:
A hollow dipstick is provided for immersion in molten material to determine the temperature of the molten material at any desired depth. The hollow dipstick is connected to an infrared detector by means of an optical fiber bundle for producing a signal indicative of the temperature of the molten material. An infrared focusing lens is provided within the hollow dipstick for transmitting the infrared radiation from the interior bottom surface of the dipstick to the fiber optic bundle. A container having a heating element therein is provided for receiving the dipstick when it is not in use so as to preheat the dipstick to a temperature close to the estimated temperature of the molten material to be measured to thereby prevent thermal shock to the dipstick upon immersion in the molten material. Alternatively the infrared detector is mounted directly on the dipstick.
Abstract:
Fiber optic probe apparatus usable for measuring temperatures with increased dynamic range and frequency domain response and desirable measurement accuracy. A black body signal source, fiber optic signal coupling, and extension of the transducer dynamic range with optical multiplexing are employed; the instrument operates in the range of 1.6 micrometers of optical energy wavelength and preferably employs recently improved indium gallium arsenide photodiode transducer devices and transducer frequency domain compensation. Use of the instrument in measuring combustion flame transient temperatures is disclosed.
Abstract:
A temperature measuring device for a metal caster comprises a radiation pyrometer including an IR diode for measuring the head radiation of the metal melt in the crucible of the metal caster. For this purpose, a graphite body dips into the metal melt. The graphite body is seated coaxially around one end of a hollow tube to whose other end is coupled a glass fiber cable which is connected with the IR evaluation diode. The graphite body which dips into the metal melt and simultaneously serves in a known manner as a closing plug for the crucible, now emits thermal radiation into the interior of the tube, such radiation substantially corresponding to the composition of the thermal radiation of a blackbody having the temperature of the metal melt. This thermal radiation is coupled into the glass fiber cable at the other end of the tube and fed to the IR diode for evaluation. This solution permits a relatively inertia-free and very precise measurement, since the measured thermal radiation no longer depends on the type of metal melt employed and, on the other hand, the IR diode employed for the measurement has a certain distance from the caster and is thus free of radiation influences on the part of the caster which could falsify the measuring result.
Abstract:
A temperature measuring device suitable for high temperature measurements in the range of 500.degree.-2400.degree. C. utilizing a blackbody cavity to emit radiation in the wavelength band of 0.3 .mu.m-1.0 .mu.m. The emitted light is transmitted to a photodetector via a high temperature ceramic fiber which is transparent to the wavelength band radiated. The radiance of the cavity is utilized as a measure of its temperature.
Abstract:
A radiation detector, as a standard reference for determining the spectral response of any detectors in the submillimeter wavelength region, comprising a conical radiation receiver whose inner surface is coated with black pigment and having a bolometer flake of gallium doped germanium soldered to its outer surface substantially midway, between its base and apex, and a cooled light pipe for introducing radiant energy into the interior of the receiver.
Abstract:
A temperature sensing device includes a probe unit on a first end and a sensor unit on a second end opposite the first end. The first end is introduced into an environment to be measured, such as an exhaust gas line from a combustion engine, and the second end is positioned in a region outside of the environment such that the sensor unit is at least partially insulated from a temperature of the environment. The probe unit, exposed to the temperature of the environment, achieves a temperature that corresponds to the temperature of the environment. The sensor unit is operable to sense the temperature of the probe unit and generate a corresponding electrical signal usable to determine a sensed temperature of the environment. The temperature of the environment can be determined on a cycle-by-cycle basis, and is usable for implementing advanced combustion strategies such as HCCI and SACI.