Abstract: For the UV OH band at 306.357 nm (transition A2Σ, ν = 0→X2Π, ν' = 0) that is frequently observed in hot gases containing oxygen and hydrogen (flames, arc plasmas), a very sensitive variation of two groups of unresolved rotational lines as a function of the temperature has been found. Using a numerical simulation, this variation has been calibrated as a function of the temperature and of the optical apparatus function. This calibration allows us to easily determine the rotational temperature without computing any line intensity.

Abstract: A method and system for calibrating radiation sensing devices, such as pyrometers, in thermal processing chambers are disclosed. The system includes a reflective device positioned opposite the radiation sensing devices and a calibrating light source which emits light energy onto the reflective device. The system is designed so that each radiation sensing device is exposed to the same intensity of light being reflected off the reflective device, which has a preset value. The radiation sensing devices are then used to measure the amount of light energy being reflected which is then compared to the preset value for making any necessary adjustments.

Abstract: A system and method for determining the temperature of substrates in a thermal processing chamber in the presence of either an oxidizing atmosphere or a reducing atmosphere is disclosed. Specifically, temperature determinations made in accordance with the present invention are generally for calibrating other temperature sensing devices that may be used in conjunction with the thermal processing chamber. The method of the present invention is generally directed to heating a substrate containing a reactive coating within a thermal processing chamber in an oxidizing atmosphere or reducing atmosphere. As the wafer is heated, the reactive coating reacts with gases contained within the chamber based upon the temperature to which the substrate is exposed. After heated, the thickness of any coating that is formed on the substrate is then measured for determining the temperature to which the substrate was heated. This information can then be used to calibrate other temperature sensing devices, such as thermocouples and pyrometers.

Abstract: A method and apparatus for active pyrometric measurement of the temperature of a body whose emissivity varies with wavelength The emissivity is inferred from reflectivity measured at two wavelengths in an irradiation wavelength band and extrapolated to a wavelength in an emission wavelength band The extrapolated emissivity is used to correct a blackbody estimate of the temperature of the body in the emission wavelength band The extrapolation, being temperature-dependent, is done iteratively Both reflectivity and emission measurements are performed via a common optical head that is shaped, and is positioned relative to the body, so that the optical head has a sufficiently large solid angle of acceptance that the measured temperature is independent of superficial roughness of the body

Abstract: Tungsten–rhenium and platinum–rhodium high-temperature thermocouples have been utilized to measure the thermal cycle and the temperature distributions for laser cladding process. Within optimized operation window, a wide range of processing parameters, and various clad materials have been used in laser cladding experiments. The clad-zone temperatures under various processing conditions fall between 1650 and 1800 °C. These results are in good agreement with those obtained by optical pyrometer.

Abstract: : In this document the non-intrusive temperature measurement techniques like pyrometry and IR- thermography and their application at high temperatures are described For a better understanding first some basic relations of thermal radiation are discussed followed by the absorption behaviour of the atmosphere and optical glasses Main properties of different IR detector types follows this chapter Chapters five and six are devoted to the description of pyrometers and IR-cameras including a comparison of different detectors, data reduction and imaging techniques Based on the experience from application of IR devices at the arc heated facility LBK, some requirements on an IR-system for its use at high enthalpy facilities are defined Results of comparative and complementary measurements of the surface temperature of several thermal protection materials using pyrometers and IR-cameras are presented in chapter nine

Abstract: Reflection errors and lack of knowledge of surface emissivities are the largest limitations to accurate temperature measurements in many industrial applications of radiation thermometry. Dual and multiwavelength pyrometers are often used as a means of compensating for unknown or varying emissivity, but the effects that reflections have on these measurements have not received much attention. A generalised reflection model is presented from which the errors and uncertainties for dual and multiwavelength pyrometers are analysed. A method for compensating for the reflection error with a dual-wavelength pyrometer is developed, but it is shown that the uncertainties are larger than would be encountered for a single-wavelength pyrometer. The errors and uncertainties for multiwavelength pyrometers are shown to be so large as to make their use impracticable.

Abstract: A method for determining oxidation in turbine buckets allows for conditional based maintenance of the turbine buckets. The method includes measuring a temperature of a turbine bucket and comparing the measured temperature to a temperature of a reference turbine bucket to determine the condition of the bucket. The method provides useful temperature data to determine if the turbine should be stopped and the bucket serviced. This method may be used in place of interval based maintenance to increase bucket life, reduce bucket failure, and increase turbine operating time.

Abstract: Improved accuracy of measurements of semiconductor wafer temperature is demonstrated in a normal-incidence optical reflectance spectroscopy system that has been modified to allow rapid switching between the measurement of wafer reflectance and wafer emission. The resulting optical system is capable of “smart” pyrometry, in which the emissivity is determined each time the temperature is measured. Measurements during heteroepitaxial growth show that the data from smart pyrometry typically differ from those of conventional pyrometry by 5–10 °C, and occasionally by as much as 20 °C for multilayer structures of AlGaAs and GaAs. Theory, experimental procedures, and calibration procedures are discussed.

Abstract: A method for determining the temperature of a surface upon which a coating is grown using optical pyrometry by correcting Kirchhoff's law for errors in the emissivity or reflectance measurements associated with the growth of the coating and subsequent changes in the surface thermal emission and heat transfer characteristics By a calibration process that can be carried out in situ in the chamber where the coating process occurs, an error calibration parameter can be determined that allows more precise determination of the temperature of the surface using optical pyrometry systems The calibration process needs only to be carried out when the physical characteristics of the coating chamber change

Abstract: A two-color array pyrometer was used to investigate morphological developments on the surface of materials undergoing self-propagating high-temperature reactions. Time sequences of temperature spatial profiles during wave propagation were found to be complex in their nature and dynamics. They contain features that are interpreted in terms of morphological changes during the process. These features include formation of cracks or voids, expansion of the sample, and formation of droplets of metals on the surface. The use of the array pyrometer for determination of the activation energy of the combustion reaction between Zr and NiO is reported.

Abstract: Semiconductor processing apparatus, including a chamber, into which a semiconductor wafer is introduced for processing thereof and a heater, which heats the wafer in the chamber. A radiation guide collects thermal radiation from a selected region of the wafer. A wafer support assembly supports the wafer and shields the radiation guide from radiation other than radiation from the region. A pyrometer, coupled to receive the radiation from the guide, analyzes the radiation to determine a temperature of the region, for use in controlling the processing.

Abstract: An active multiband pyrometer for non-contact temperature measurement of objects of unknown and spectrally-dependent emissivity was developed. It enables temperature measurement of the objects of temperature within 500C-1200C range with a speed up to 200 Hz. The pyrometer consists of a source of infrared radiation that emits radiation on the object under measurement and a receiver that measures radiation reflected and emitted by the object into four narrow spectral bands. Tests show that the developed pyrometer enables temperature measurement of real selective objects with the standard uncertainty equal to 1 % of the output temperature in its temperature measurement range.

Abstract: A method is disclosed for processing a silicon workpiece including a hybrid thermometer system for measuring and controlling the processing temperature where fabrication materials have been or are being applied to the workpiece. The hybrid thermometer system uses optical reflectance and another thermometer technique, such as a thermocouple and/or a pyrometer. Real-time spectral data are compared to values in a spectrum library to determine the “surface conditions”. A decision is then made based on the surface conditions as to how the temperature is measured, e.g., with optical reflectance, a pyrometer, or a thermocouple, and the temperature is measured using the appropriately selected technique. Utilizing the hybrid thermometer system, the temperature of a silicon workpiece may be accurately measured at low temperatures while accounting for the presence of fabrication materials.

Abstract: A steam-cooled second-stage nozzle segment has an outer band and an outer cover defining a plenum therebetween for receiving cooling steam for flow through the nozzles to the inner band and cover therefor and return flow through the nozzles. To measure the temperature of the buckets of the stage forwardly of the nozzle stage, a pyrometer boss is electron beam-welded in an opening through the outer band and TIG-welded to the outer cover plate. By machining a hole through the boss and seating a linearly extending tube in the boss, a line of sight between a pyrometer mounted on the turbine frame and the buckets is provided whereby the temperature of the buckets can be ascertained. The welding of the boss to the outer band and outer cover enables steam flow through the plenum without leakage, while providing a line of sight through the outer cover and outer band to measure bucket temperature.

Abstract: The invention relates to a method and a sensor (1; 1a, 1b) for measuring temperature. Known pyrometric methods of gas temperature measurement already exist. According to the invention, particles (14) in the gas (12) or in the flame are heated to incandescence with a laser pulse (7), the induced continuum heat radiation of the particles (14) is measured pyrometrically, the particle temperature T is calculated and the original gas temperature T° is determined from said particle temperature by calculation and/or scaling. The calculation can be carried out with a theoretical model for the energy balance of the heated particles (14) and the scaling with an independent gas temperature measurement. The pyrometric measurements can be analysed monochromatically, bichromatically or with broadband and especially independently of the particle-emissivity. In preferred embodiments, a one or two-dimensional gas temperature profile is determined. The inventive method is contactless, avoids disturbances in the gas flow (13), is characterised by a very high measuring sensitivity and is especially suitable for measuring the temperature of gases or flames in gas turbines.

Abstract: Approximate methods for the determination of a temperature field using pure emission pyrometry applied to a two-dimensional nonoptically thin flame without variation along a line of sight are presented. In the absence of an absorption measurement, emission pyrometry depends on theoretical spectral information. Limitations of existing techniques stem from the fact that spectral information is a function of temperature only for the optically thin situation, by and large the situation to which current techniques apply, and temperatures above 1000 K. Through extensive narrow-band calculation using a simulated flame over polymethylmethacrylate, we show that the spectral information contained in the equivalent bandwidth ratio is approximately a constant for the 2.8 μm/1.8 μm band pair and appropriate bandwidths. The constant can be evaluated from emission measurements at a point where the temperature is known or can be estimated using, e.g., the maximum flame temperature of a simulated flame and the peak band intensities. The temperature field evaluated with this approximately constant value of the equivalent bandwidth ratio, A r , is accurate to within five percent for temperatures down to 450 K.

Abstract: A new method of optical pyrometry for sooting flames has been developed that combines absorption and emission measurements, thereby reducing the uncertainty in measured soot temperature when compared to commonly used methods that involve only emission measurements. Large uncertainties in soot optical properties that hamper conventional two-color techniques are avoided by making direct measurements of soot emissivity instead of using emissivity models. Laser modulation enables combined measurements of laser transmission and flame emission at the same wavelength. Single-color and two-color absorption/emission techniques were evaluated with modulated diode lasers at 830 nm and 1300 nm. Laser transmission through a rich laminar premixed ethylene/air flame was measured at each of the two wavelengths, while also measuring flame emission at the same wavelengths. Results for an example case showed a reduction in the uncertainty of measured temperature from greater than + 75 K with conventional emission-only methods, to f 20 K with modulated absorption/emission pyrometry. Advantages over the conventional method are greatest for soot

Abstract: A new type of multi point multi wavelength pyrometer for solid propellant rocket engine flame distribution measurement was developed successfully The instrument can record the radiation fluxes of 8 wavelengths for uniformly distributed 6 points on the target surface, which are well defined by the holes on the field stop lens The fast response pyrometer with the specially designed synchronous data acquisition system can assure that the recorded thermal radiation fluxes of different spectrum region are of the same time and the same true temperature even with dramatically changed targets

Abstract: PROBLEM TO BE SOLVED: To provide a method by which the radiation-rate can easily be corrected against the variation of the radiation ratio on the surface of a strip and by which the measuring accuracy is improved by using an inexpensive single-color pyrometer in comparison with an expensive two-color pyrometer and to provide an inexpensive strip temp. measuring instrument. SOLUTION: In the measurement of the temp. of the strip S traveling a strip continuous annealing furnace 1 with a monochronic thermometer 4, the radiation rate (en) is obtd. by Lm=en×Lb (Ttrue) (wherein, Lb is a black body radiation intensity) from the temperature (Ttrue) measured with a thermocouple type thermometer 5 in a period when the strip temp. can be regarded as constant at a measuring objective point of the strip S with a strip temp. calculating unit 6 and radiation energy (Lm) measured with the single-color pyrometer 4, and then the strip temp. measured with the single-color pyrometer is corrected with the obtd. radiation rate (en).

Abstract: PURPOSE: A method and a device for measuring the temperature of heating object are provided to measure a temperature to all heating steel material and to apply to the surface temperature measurement of other heating objects besides the steel material. CONSTITUTION: A reflection plate(2) is arranged on the temperature measurement surface of a heating object, and an insulation member(3) is attached to a rear face of the reflection plate. The temperature of the reflection plate is close to the surface temperature of the heating object. The measurement wave area is limited less than 0.6 micrometer with a radiation pyrometer through a penetration opening part(5), and the surface temperature is measured. Herein, the penetration opening pare is formed by being connected to penetrate through the reflection plate and the insulation member, and the radiation pyrometer is installed on a rear part of the insulation member. Accordingly, the surface temperature is measured with the radiation pyrometer while keeping the difference between the reflection plate temperature and the surface temperature into an approximate range.

Abstract: What is to our knowledge a novel infrared thermometer (IRT) for remote measurement of the temperature rise (-20–100 K) above the variable ambient (270–320 K) of a distant object is described. A radiation-balancing method is successfully extended to the near-ambient temperature range by variation of the temperature of a built-in blackbody, until the radiation from it equals the radiation from the source, so that its temperature is proportional to that of the source. Another feature believed to be novel is simplifying the design by elimination of the need for cooling the blackbody for subambient temperature range by use of a second blackbody, strategically located, which is heated to achieve radiation balance. Detailed theoretical analysis is given, showing that the IRT can measure remotely the total emissivity or even the electric current or voltage. Resistive inserts are proposed for improving the accuracy of current measurement. A method is proposed for simultaneous remote measurement of absolute temperature and emissivity by variation of the heating current and the aperture of the blackbody for radiation balancing in two bands so that prior knowledge of the object’s emissivity is not needed.

Abstract: In a harsh environment as at the continuous caster, the measurement of the temperature of molten steel can be difficult. Normally, an operator inserts thermocouples into molten steel and has both to attach and remove the probe at the tip of a thermocouple for each measurement.A different measuring method has been developed to overcome these difficulties and carry out automatically the measurements.