Abstract: A laser materials processing system for computing a real time cooling rate experienced on a workpiece and responsively controlling the operation of a materials processing laser. An image of a point of laser beam-material interaction is transmitted via imaging optical fibers to ratio pyrometer apparatus which provides temperature proportional signals. The temperature signals are used to compute cooling rate.

Abstract: A method of measuring a furnace temperature in a hot isostatic pressing unit, including the steps of condensing a thermal radiation beam from an end portion of a closed-end tube in a high-pressure furnace of the hot isostatic pressing unit by an optical system, feeding the radiation beam from the optical system to a detector to measure the temperature in the furnace, wherein the optical system includes a solid lens having an incoming surface formed by a spherical surface with center at a temperature measurement objective point and having an outgoing surface formed by a spherical surface with center at a light collecting point, so as to condense a radiant energy from the temperature measurement objective point. In another aspect of the invention, the steps further comprising removing a wavelength of absorption by a low b.p. metal gas vaporized from a treatment material in the furnace or a capsule glass.

Abstract: A high optical efficiency dual spectra pyrometer for measuring the temperature of a target includes an optical guide for collecting and guiding a target optical beam to a detection module which comprises an interference filter and photodetectors adjustably positioned to provide efficient coupling of the target optical beam thereto. The pyrometer additionally includes a signal processor which receives the signals from the photodetectors, as well as signals indicative of an estimated fireball equivalent black body temperature and the spectral width difference between the two detector signals, and provides a compensated temperature signal.

Abstract: Method and apparatus are provided for simultaneously measuring temperature and pressure in a class of crystalline materials having anisotropic thermal coefficients and having a coefficient of linear compression along the crystalline c-axis substantially the same as those perpendicular thereto. Temperature is determined by monitoring the fluorescence half life of a probe of such crystalline material, e.g., ruby. Pressure is determined by monitoring at least one other fluorescent property of the probe that depends on pressure and/or temperature, e.g., absolute fluorescent intensity or frequency shifts of fluorescent emission lines.

Abstract: A radiation thermometer comprises two radiation detectors for detecting radiation in wavelength bands centered on two different wavelengths .lambda..sub.1,.lambda..sub.2 (where .lambda..sub.1 >.lambda..sub.2) from a rotating body such as a gas turbine motor and for generating first and second signals S.sub.1,<S.sub.2 >respectively related to the radiance profile around said body and the average radiance around said body. A time averaging circuit generates a signal <S.sub.1 >representing an average value of said first signal. A dividing circuit generates a signal related to the ratio of <S.sub.1 >to <S.sub.2 >; and a monitor monitors at least one of said signals, predetermined arithmetic combinations of said signals, and quantities related thereto and provides corresponding output signals.

Abstract: A temperature detection pyrometer for determining the temperature of a turbine blade detects radiation reflected and emitted from the turbine blade. The reflected radiation is a result of flame and hot carbon particles rather than the emission representing the blade temperature. The radiation is divided into two channels, each of which detects radiation in different, but preferrably overlapping wavelength bands, to detectors providing currents proportional to the radiation intensity in the respective channel. The signal from one channel is weighted with respect to the signal from the other by a constant that is equal to the ratio of the radiation in the two channels which is the attributable to the reflected radiation. The difference between the signals, after weighting the one signal by the constant provides an output that is a function of blade temperature only so the blade temperature may be obtained from a calibration curve or a look-up table.

Abstract: A device for the pyrometric measurement of the temperature of a graphite tube furnace for flameless atom absorption spectroscopy is described. According to the invention, a pyroelectric detector is used as radiation receptor. The radiation flux at high temperatures is limited by a cut-off filter which starts at about .lambda..gtoreq.1 .mu.m and which, at the same time, can be constructed as radiation collector lens. It preferably consists of germanium. The detector signal is amplified in preferably three amplification stages which are connected under microprocessor control in dependence on the preselectable temperature ranges of the graphite tube furnace. A temperature measuring range from room temperature to 3,000.degree. C. is achieved.

Abstract: A method and apparatus are provided for remotely monitoring temperature. Both method and apparatus employ a temperature probe material having an excitation-dependent emission line whose fluorescence intensity varies directly with temperature whenever excited by light having a first wavelength and whose fluorescence intensity varies inversely with temperature whenever excited by light having a second wavelength. Temperature is measured by alternatively illuminating the temperature probe material with light having the first wavelength and light having the second wavelength, monitoring the intensity of the successive emissions of the excitation-dependent emission line, and relating the intensity ratio of successive emissions to temperature.

Abstract: A method and apparatus for calculating the equivalent blackbody color temperature of incandescent lamps. A lamp analyzer having photosensors which detect the red and blue components of lamp radiation and convert the components to analog currents. The currents pass through a multiplex system and are converted into a signal with voltages proportional to the photosensor currents. A signal conditioner circuit removes switching transients, damped oscillations and cell noise from the circuit, and an automatic gain controller system insures linearity in the signal. The ratio of the blue component of the signal to the red component is then determined by a ratio computer, producing an output which is linearized and scaled by a translator to display the corresponding color temperature of the lamp in Kelvins.

Abstract: A reflection corrected radiosity optical pyrometer includes an optical guide for receiving a target optical beam from a turbine blade in a jet engine. The target optical beam is provided to a detector module that divides the target optical beam into two beams, one having a spectral width selected to be less than the target optical beam spectral width. A signal processor receives signals from the detector module indicative of the energy of the two beams, calculates a reflection corrected energy signal directly therefrom and provides a correct target temperature signal.

Abstract: A novel dual spectra optical pyrometer is characterized by a serial array of photodetectors. The first photodetector absorbs a spectral portion of a target optical beam incident thereto, and passes the remainder optical beam to the second photodetector. Signals from both photodetectors are provided along with signals indicative of the first detector's spectral absorption and an estimate of the equivalent black body temperature of a fireball to a signal processor which provides a compensated temperature signal therefrom.

Abstract: A dual spectra optical pyrometer having an air pressure sensitive shutter for measuring the temperature of a turbine blade includes a sight tube located in the jet engine receiving an optical beam from the turbine blade. Located within the sight tube is a shutter responsive to the jet engine air pressure and providing the turbine blade optical beam only above a selected threshold magnitude of said air pressure. A detection module receives and divides the turbine blade optical beam and provides signals to a signal processor. From these signals and signals indicative of an estimated fireball equivalent black body temperature and the spectral width difference between the two detector signals, the signal processor provides a signal indicative of a compensated turbine blade temperature.

Abstract: A method of more accurately measuring the true surface temperature of metal alloy objects without contacting the same. The surfaces of the objects have unknown emissivities that change and that are less than unity. The method includes the step of providing objects having surfaces that radiate infrared energy. The radiated energy is measured at two wavelengths, and a first measurement is provided that is a function of the ratio of the energies at the two wavelengths. The radiated energy is also measured at a single, narrow band wavelength, and a second measurement is provided that is a function of the radiated energy. The two measurements are then electrically combined to provide measurements of radiated energy and thus temperature measurements that are or at least are closer to the true temperature than either of the first or second measurements.

Abstract: A novel dual spectra optical pyrometer for use in in-flight control of jet engines includes an optical probe containing a shutter sensitive to the air pressure within the jet engine. The shutter provides an optical beam from rotating turbine blades to an optical fiber only above a threshold pressure. A serial array of photodetectors receives the optical beam and provides first and second signals therefrom. A signal processor receives the first and second signals as well as signals indicative of the energy ratio therebetween, and provides reflection corrected energy signals from the difference between the first signals and the product of the energy ratio signals and the second signals.

Abstract: An apparatus for measuring bath temperature of metallurgical furnaces through a tuyere is disclosed. The apparatus comprises a periscope adapted to be inserted into a tuyere, a fiber optic cable having one end connected to the periscope for receiving radiation entering the tuyere from the bath of a furnace, and a two wavelength pyrometer connected to the other end of the fiber optic cable for analysing the radiations transmitted through the fiber optic cable to provide an indication of the temperature of the bath.

Abstract: The present invention relates to a procedure and a device for determination of the temperature of an object by measurement of electromagnetic radiation emitted by this object. A portion of the radiation emitted by the object of measurement is transmitted by a transmission device to a wavelength dividing device.The wavelength dividing device causes a portion of the spectrum of the radiation corresponding to the spectral sensitivity range of the detector or pair of detectors to be distributed across the radiation-sensitive surface of the detector or pair of detectors. The detector senses the position of the center of gravity of the illuminated spectrum which is converted by the signal processing unit to temperature information, and displayed by an output device.Using a sole position-sensitive detector, the relative magnitude of two currents I.sub.1 and I.sub.2 indicates the position of the center of gravity.

Abstract: In the temperature measuring apparatus disposed herein, a first intermediate output signal is obtained which is a function of the ratio of the brightness of a target at two different wavelengths and a second intermediate output signal is generated which is a function of the brightness of the target at a single wavelength. The two intermediate output signals are combined in preselectable proportion to yield a temperature output signal which is relatively insensitive to target surface characteristics.

Abstract: An apparatus is described which is capable of producing an image of a smelt bed of inorganic chemicals collected at the bottom of a kraft pulp recovery boiler. The image produced is free of interferences of fume particles and gaseous radiation which have obscured prior attempts to view hot surfaces under such environmental conditions. The apparatus includes an industrial closed circuit video camera fitted with an infrared imaging detector or vidicon tube. An objective lens obtains the image. An optical filter interposed between the lens and the vidicon is a key element of the invention and is selected to reject radiation less than about a micrometer to avoid fume interference. The filter is further selected to reject all but limited ranges of radiation to avoid gaseous species overlying the smelt bed which are strongly emitting and absorbing. As an example, a spectral filter centered at 1.68 micrometers with a band width of 0.07 micrometer is suitable for imaging a kraft recovery smelt bed.

Abstract: A two-wavelength I.R. pyrometer for monitoring the rapid heating of materials by C W lasers or electron beams. The I.R. radiated from the material is separated into two closely adjacent wavelengths and signal values representative of those wavelengths are obtained. These signal values are then processed through an electronic circuit where the signal value of one of the signals is held substantially constant by a feedback control while the other signal value is influenced by approximately the same feedback control applied to the first signal value and wherein the resultant signal values are then processed through a circuit determining a ratio of one signal value divided by the other. This is then a measure of the temperature of the material. Also disclosed is a chopper wheel for a two-wavelength I.R. pyrometer. The wheel has a plurality of circumferentially extending I.R. filters of alternating wavelengths (.lambda..sub.1, .lambda..sub.2).