Abstract: An original technique for the measurement of high-temperature phase transitions was implemented based on a laser-heating method, enabling chemically unstable, refractory materials to be melted under controlled conditions. This technique includes two independent but correlated methods: In the first, fast multichannel pyrometry is employed to measure thermograms and spectral emissivity; in the second, a low-power probe laser beam is used for the detection of reflectivity changes induced by phase transitions on the sample surface. The experiments are carried out under medium ( approximately 10(2) kPa) or high ( approximately 10(2) MPa) inert-gas pressures in order to kinetically suppress evaporation in volatile or chemically instable samples. Two models for the simulation of the laser-heating pulses are as well introduced. Some results are presented about the successful application of this technique to the study of the melting behavior of oxides such as UO(2+x), ZrO(2), and their mixed oxides. The method can be extended to a broad class of refractory materials.

Abstract: An evaluation of the Stardust spacecraft forebody heat shield design was conducted to address uncertainties in heating rate calibrations done in the original development and qualification efforts for the Stardust project. This paper reports the results of additional arcjet tests and analyses carried out to determine the ablative and thermal performance of the low density Phenolic Impregnated Carbon Ablator (PICA) material used for the Stardust design. Testing was done under conditions that simulate the peak convective heating conditions (1200 W/cm 2 and 0.5 atm) expected for Earth entry of the Stardust Sample Return Capsule. Test data were used to adjust iteratively the thermophysical properties used in an ablative material response computer code to match the experimental in-depth temperatures for peak convective heating conditions. The PICA recession rates and maximum internal temperatures were satisfactorily predicted by the computer code with the revised properties. Predicted recession rates were also in acceptable agreement with measured rates for heating conditions 37% greater than the nominal peak heating rate of 1200 W/cm 2 . Although the experimental and computer model maximum internal material temperatures were in agreement and are considered to validate the Stardust heat shield design, the measured in-depth temperature response data show consistent temperature rise deviations that may be caused by an undocumented endothermic process within the PICA material that was not accurately modeled by the computer code. Predictions of the Stardust heat shield performance based on the present evaluation provide evidence that the maximum adhesive bondline temperature will reach about 115˚C, considerably less than the maximum allowable of 250˚C and the design condition of 190˚C. The evaluation also suggests that even with a 25 percent increase in peak heating rates, the total recession of the heat shield would be 1.5 cm, a small fraction of the as-designed thickness of 5.82 cm. Together, these results give confidence in the Stardust heat shield design.

Abstract: The temperature of metal droplets is essential for clarifying the phenomenon of metal droplet transfer and the melting behaviour of wire; also, it governs the emission of fumes. On the other hand, in situ measurement of the temperature of a metal droplet formed at the tip of a wire during welding was difficult. Hence, this temperature was obtained in many experiences of measurements by such a way that several numbers of metal droplets were collected in a calorimeter to measure the amount of heat content of metal droplet and the heat was converted to temperature. With this way, however, the reliability of the measurement is not necessarily high because the heat loss of the metal droplet during the time when detaching from the wire tip and entering into the calorimeter has to be estimated properly. In this research, two-colour pyrometry has been conducted to obtain the temperature of metal droplets, in which metal droplets have been photographed by a high-speed camera during arc welding, two wavelengths (95...

Abstract: Growing demands on the quality of plasma-sprayed coatings require reliable methods to monitor and optimize the spraying processes. As the coating microstructures are dependent on the characteristics of the powder feedstock, particle in-flight diagnostics is of great importance. In particular, the melting status of the particles is critical in this regard. Thus, the accurate determination of the particle temperature is necessary. In-flight particle temperature measurements during atmospheric plasma spraying (APS) of tungsten, molybdenum, and yttria-stabilized zirconia by two-color pyrometry were analyzed statistically. The diagnostic tool applied is the DPV-2000 (Tecnar). The particle temperature distributions allow for assessment of the melting status of the particles as well as the identification of the melting temperature and particle fractions in the molten and solidification state. Furthermore, the relevant systematic and material-dependent sources for measurement errors using two-color pyrometry were investigated. Their influence was carefully estimated and corrected. As long as there are reliable data available on the emissivity of the powder material, good agreement between the corrected measured melting temperatures and the reference data can be expected.

Abstract: Numerical simulation of vacuum arc re-melting, pressurized or protective electro-slag re-melting, and ingot casting have become quite important in the metal industry. However, a major drawback of these simulation techniques is the lack of accurate thermophysical properties for temperatures above 1,500 K. Heat capacity, heat of fusion, density, and thermal conductivity are important input parameters for the heat transfer equation. Since, direct measurements of thermal conductivity of alloys in the liquid state are almost impossible, its estimation from electrical conductivity using the Wiedemann–Franz law is very useful. The afore-mentioned thermophysical properties of several steels are investigated within the context of an ongoing project. Here, we present a full set of thermophysical data for the chromium–nickel–molybdenum steel meeting the standard DIN 1.4435 (X2CrNiMo18-14-3); these values will be used by our partner to simulate various re-melting and solidification processes. Wire-shaped samples of the steel are resistively volume-heated, as part of a fast capacitor discharge circuit. Time-resolved measurements with sub-μs resolution of current through the specimen are performed with a Pearson probe. The voltage drop across the specimen is measured with knife-edge contacts and ohmic voltage dividers, the temperature of the sample with a pyrometer, and the volumetric expansion of the wire with a fast acting CCD camera. These measurements enable the heat of fusion, the heat capacity, and the electrical resistivity to be determined as a function of temperature in the solid and liquid phases. The thermal conductivity and thermal diffusivity are estimated via the Wiedemann–Franz law.

Abstract: We present a theoretical analysis of two-color pyrometry applied to optical diagnostics. A two-color pyrometer built with a single CCD is advantageous due to the simple system design. We evaluate the possibility and degree of ill-conditionness on the basis of measurement uncertainties for different measurement approaches of this two-color system. We classify measurement approaches. The corresponding ill-conditionness criterion is established. The greater the criterion value is, the worse the ill-conditioned degree of solution is. So, the optimum choice of measurement approach for the two-color system is achieved through intercomparison of the criterion values. Numerical examples are also given to illustrate this point. The theoretical analysis not only provides an effective way of evaluating different measurement approaches, but also may help us to better understand the influences that determine the choices between wavelength/waveband measurements and calibration/noncalibration modes for temperature and soot distribution.

Abstract: Introduction Thermal and Flow Measurements Some Examples of Thermal and Flow Measurements Characteristics of Measurement Systems Time Response of Measurement Systems Time-Series Analysis and Signal Processing Error Estimates and Uncertainty Analysis Error Estimates Using Gaussian Distribution Data Regression Uncertainty Analysis Dimensional Analysis and Similitude Basic Science and Engineering in Thermal and Flow Measurements Basic Measurements of Pressure, Temperature, and Flow Rates Pressure Measurements Manometers Pressure Transducers Based on Elastic Strain Piezoelectric Transducers Some Implementation Issues Temperature Sensors Temperature Measurements Based on Thermal Expansion of Materials Thermocouples Resistance-Based Temperature Sensors Pyrometer Measurements of Temperature Strain Gauges Flow Rate Measurements Obstruction Flowmeters Rotameters Turbine Flowmeters Thermal Mass Flowmeters Flow Velocity Measurements Using Pitot and Static Pressure Probes Flow Visualization and Image Analysis Streamlines, Streaklines, and Pathlines Direct Photography Using Flow Tracers Surface Imaging Using Thermochromatic Liquid Crystals and Pressure-Sensitive Coatings Shadowgraph and Schlieren Imaging Interferometry Laser Tomographic Imaging Image Processing and Analysis Image Acquisition Basic Image Operations Image Enhancements Edge Detection Flow Velocity Measurements Laser Doppler Velocimetry The Operating Principle Operational Setup Particle Seeding Hot Wire Anemometry Operating Principle Operational Considerations Particle Image Velocimetry Particle Image Density Stereoscopic PIV for Three-Component Velocity Measurements Other Image-Based Methods Optical Diagnostics for Measurements of Species Concentrations and Temperature Rayleigh Scattering Rayleigh Scattering Theory Applications of Rayleigh Scattering Mie Scattering Applications and Assessments Raman Scattering Molecular Energy and Spectroscopy Laser-Induced Fluorescence Thermometry Based on LIF Vibrational and Rotational Spectroscopy Fourier-Transform Infrared Spectroscopy Particle Sizing and Two-Phase Flow Measurements Parameters to Characterize Groups of Particles Light Scattering and Extinction Measurements of Particle Size Laser-induced Incandescence Measurements of Particle Volume Fraction and Size Laser Diffraction Phase Doppler Analysis Particle Mass Flux Measurements Fiberoptic Correlation Method Acoustic Measurements Capacitance Probes Isokinetic Sampling Gas Sampling Measurements Sampling Probes Non-Dispersive Infrared (NDIR) Analyzers Measurements of Nitric Oxides Hydrocarbon Analysis Measurements of Sulfur Oxides Gas Chromatography Mass Spectroscopy Scaled Measurements MEMS Devices Microfabrication Methods Microfluidic Sensors and Devices Pressure and Temperature Sensors Bio- and Chemical Sensors Nanotechnology Sensors Microscopic Imaging Techniques LIDARS Appendix A: Electronic Devices. Operational Amplifiers Inverting Amplifier Noninverting Amplifier Current-to-Voltage Converter Differential Amplifier Trigger Electronics Frequency Filters Filter Basics Active Filters Appendix B: Optics Optical Instruments Diffraction Diffraction Grating Interference Appendix C: Electromagnetics and Electromagnetic Radiation Maxwell's Equations Electromagnetic Wave Equation Radiative Transfer Equation Blackbody Radiation Appendix D: Quantum Mechanics and Atomic/Molecular Structure Vibrational and Rotational Energy of Simple Molecules Energy Transitions and Spectroscopy

Abstract: The thermal stability of kerosene-based rocket propellants enables successful regenerative cooling of liquid rocket engines. This work experimentally investigates the effect of sulfur level and red dye concentrations on the thermal stability of RP-1 and RP-2 rocket fuels. A high Reynolds number thermal stability test unit evaluated various compositions of the fuels. The experiment consisted of an electrically heated, stainless steel capillary tube with controlled fuel outlet temperature. As deposits built up inside the capillary tube, an optical pyrometer monitored external temperature profiles. Multiple runs at individual test sites provided results on measurement repeatability. Testing at two facilities provided results on measurement reproducibility. The technique is able to distinguish between RP-1 and RP-2 rocket fuels which mainly differ in their sulfur concentrations. Red dye is shown to have a measurable negative impact on thermal stability. Carbon burn-off analysis of residue in the capillary tubes correlates with the external temperature results.

Abstract: The utility model relates to the metallurgical plant in-furnace strip steel temperature online measuring technical field, and provides an in-furnace strip steel temperature measuring device which comprises a radiation pyrometer, a contact thermometer, a temperature measuring cover and a data processing system The in-furnace strip steel temperature measuring device adopts contact temperature measurement to demarcate noncontact temperature measurement, and can carry out online temperature measurement comparison of the same material point; moreover, the device can realize synchronous check so as to greatly improve measuring precision; in addition, the in-furnace strip steel temperature measuring device also provides a convenient and effective means which can be used to check various steel types and various target temperatures

Abstract: A simple method of monitoring 2-D temperature images from monochromatic gray images of flames captured from utility boilers, and reference temperatures measured by two-color pyrometry, are presented in this paper. In a 670 t/h utility coal-fired boiler furnace, the magnitude of the combustion temperature fluctuation can reach as high as 180 K under normal conditions. Furthermore, a two-loop combustion control strategy was proposed with steam pressure as its outer-loop control variable and the radiant energy signal as the inner-loop control variable. Simulation on the single-and two-loop control strategies clearly indicates that the two-loop control strategy can realize a more economical utilization of fuel. It also ensures steady steam pressure and safer conditions for the superheater surface tubes (not to be overheated) making the boiler respond quickly to the load change.

Abstract: A method is suggested of time-space analysis of temperature fields on the surface of tungsten cathode of a high-current electric arc using a VS-FAST high-speed video camera (manufactured by VideoScan, Moscow). The importance of contribution made by plasma radiation to the cathode surface emissivity being measured is considered, and the methods of taking this contribution into account are identified. Experiments reveal the possibility of using this high-speed video camera as a pyrometer providing for time resolution up to 2 μs and space resolution of about 30 μm.

Abstract: The invention relates to a method for the camera-assisted detection of the radiation intensity of a particularly gaseous chemical reaction product. According to the invention, an RGB color camera (8) is used to detect the radiation intensity of a reaction product in a red, green or blue wavelength range. The respective blue signal (IB) of the RGB color camera (8) is used to produce a band radiation value (BS) of the respective reaction product. The respective red and/or green signal (IR, IG) of the RGB color camera (8) is used to produce a thermal radiation value (TS) by means of pyrometry or comparative pyrometry. The difference of the respective range radiation value (BS) and the respective associated thermal radiation value (TS) is used to produce an emission rate (K) for the radiation intensity of the respective reaction product.

Abstract: In a laser annealing system for workpieces such as semiconductor wafers, a pyrometer wavelength response band is established within a narrow window lying between the laser emission band and a fluorescence emission band from the optical components of the laser system, the pyrometer response band lying in a wavelength region at which the optical absorber layer on the workpiece has an optical absorption coefficient as great as or greater than the underlying workpiece. A multi-layer razor-edge interference filter having a 5-8 nm wavelength cut-off edge transition provides the cut-off of the laser emission at the bottom end of the pyrometer response band.

Abstract: A method and system are implemented to detect gas turbine blade problems in real time and provide more accurate prediction capabilities than known techniques due to inclusion of physics-based correction and temperature modeling methods for the hot gas path parts lifing. The system and method use pyrometer data and operational data to generate physics-based corrections of pyrometer data and physics-based bucket temperature estimations and failure signatures.

Abstract: An integrated investigation approach for temperature measurement and control of plasma sprayed coating is presented in this paper. It is based on infrared (IR) pyrometry combined with specific robot scanning trajectories. The temperature evolution was continuously detected and recorded during preheating, spraying, and cooling stages. Then the two specific factors, periodic average temperature and periodic standard deviation, were adopted to evaluate the temperature variation and the fluctuation of the thermal cycle relevant to one spraying period. These two factors were successful in describing the temperature variation during experimental processing sets. Moreover, the influence of processing parameters of Z-type robot spray trajectory, including spray distance, scanning velocity, and scanning step on coating temperature is experimentally researched and explained reasonably by comparing the two factors.

Abstract: Temperature measurement using a pyrometer in a processing chamber is described. The extraneous light received by the pyrometer is reduced. In one example, a photodetector is used to measure the intensity of light within the processing chamber at a defined wavelength. A temperature circuit is used to convert the measured light intensity to a temperature signal, and a doped optical window between a heat source and a workpiece inside processing chamber is used to absorb light at the defined wavelength directed at the workpiece from the heat source.

Abstract: The construction, the calibration, and the use of the NIST Thermodynamic Radiation Thermometer (TRT) to measure the temperature of the gold freezing temperature blackbody and a variable-temperature blackbody from 800 to 2,700°C are described. These temperature determinations are detector-based and derived from the electrical substitution radiometer and length units. The TRT is constructed using a cooled, near-infrared enhanced silicon detector with a room-temperature-stabilized five-position filter wheel. The characteristics of the TRT, such as the size-of-source effect and preamplifier linearity, are determined. The measured temperatures are compared with those obtained using the NIST Absolute Pyrometer 1 (AP1) and the current NIST standard radiation thermometer, the Photoelectric Pyrometer (PEP). After the performance assessments, the TRT will become the standard radiation thermometer for disseminating radiance temperature scales in the United States.

Abstract: This paper describes a fast multi-channel radiation pyrometer that was developed for warmdense-matter experiments with intense heavy ion beams at Gesellschaft fur Schwerionenforschung mbH (GSI). The pyrometer is capable of measuring of brightness temperatures from 2000 K to 50000 K, at 6 wavelengths in visible and near-infrared parts of spectrum, with 5 nanosecond temporal resolution and several micrometers spatial resolution. The pyrometer's spectral discrimination technique is based on interference filters, which act as filters and mirrors to allow for simultaneous spectral discrimination of the same ray at multiple wavelengths.

Abstract: Temperature field measurements in the chip are performed during high speed machining of a low carbon steel (XC18) and a medium carbon steel (42CrMo4). An original mechanical device based on the propelling of a projectile by decompression of air allows to investigate a wide range of cutting speeds from 10 to 120 m/s. The technique of temperature measurement using the principle of pyrometry in the visible spectral range is realised with an intensified CCD camera with a very short exposure time. Temperature maps presented for the two steels confirm that the heating in the chip is not uniform and the presence of a maximal temperature area. The effects of cutting parameters such as chip thickness and cutting velocity are presented.

Abstract: The plume temperature of a solid propellant rocket engine (SPRE) is a fundamental parameter in denoting combustion status. It is necessary to measure the temperature along both the axis and the radius of the engine. In order to measure the plume temperature distribution of a solid propellant rocket engine, the multi-spectral thermometry has been approved. Previously the pyrometer was developed in the Harbin Institute of Technology of China in 1999, which completed the measurement of SPRE plume temperature and its distribution with multi-spectral technique in aerospace model development for the first time. Following this experience, a new type of multi-target multi-spectral high-speed pyrometer used in the ground experiments of SPRE plume temperature measurement was developed. The main features of the instrument include the use of a dispersing prism and a photo-diode array to cover the entire spectral band of 0.4 to 1.1 microm. The optic fibers are used in order to collect and transmit the thermal radiation fluxes. The instrument can measure simultaneously the temperature and emissivity of eight spectra for six uniformly distributed points on the target surface, which are well defined by the hole on the field stop lens. A specially designed S/H (Sample/Hold) circuit, with 48 sample and hold units that were triggered with a signal, measures the multi-spectral and multi-target outputs. It can sample 48 signals with a less than 10ns time difference which is most important for the temperature calculation.

Abstract: We describe the configuration of two new optical diagnostics for laser‐driven dynamic‐compression experiments to multi‐Mbar pressures. A streaked optical pyrometer (SOP) has been developed to provide temporally and spatially‐resolved records of the thermal emission from shock‐compressed samples. In addition, temporally‐resolved broadband reflectivity is measured between 532 and ∼850 nm by supercontinuum generation in an optical fiber. These new tools expand capabilities to probe the thermal and electronic states of matter at high pressures and temperatures using the Lawrence Livermore National Laboratory's Janus laser.

Abstract: The temperature of the hot zone created by impact of a high power density electron beam (e-beam) needs to be monitored for reasons concerning process evaluation and safety. In high throughput e-beam evaporators, direct line of sight viewing of the hot zone using an optical pyrometer on a continuous basis is ruled out due to opacity introduced by rapid coating of the vacuum windows within a few seconds. An alternative that permits continuous visual monitoring relies on a periscopic arrangement that makes use of process generated thin film mirror formed by deposition of evaporating metal atoms. This paper discusses the additional error introduced by the thin film mirror during this type of monitoring arrangement for the case when a two-color pyrometer is used as temperature sensor. The dominant factors, namely temperature, pressure and reactivity of metal being evaporated, which affect the measured temperature are found and their effects are confirmed through our experimental data. It is shown that due to dynamically changing spectral reflectivity of the thin film mirror, the additional error in measured temperature could be in the range of ~0–35% of the value recorded by direct viewing method depending upon the above parameters. Finally, as an alternative, we propose a novel method and show through calculations that this method avoids errors experienced in the periscopic method and yet allows extended continuous monitoring time.

Abstract: A fiber optic two-color pyrometer was developed for brake disc surface temperature measurement. The two-color pyrometer is composed of a fluoride glass fiber and two HgCdTe detectors equipped with bandwidth filters. The two-color pyrometer allows the measurement of brake disc temperature in the 200-800 °C range with a time resolution above 7 µs. Calibration formula for the signals obtained using a blackbody of known temperature are used to compute the true temperature of a known temperature target. Finally the two-color pyrometer is used to measure the disc surface temperature and the surface emissivity during braking. Nomenclature A: Amplification constant, V.W -1 .m 3 .sr Greek symbols K: error coefficient �: measurement error

Abstract: Purpose – This paper aims to examine the use of a commercial pyrometer to measure the surface temperature of workpieces as machining takes place The pyrometer readings are to be compared with model predictionsDesign/methodology/approach – The pyrometer was mounted on an industrial milling machine and the temperature of the workpiece was measured behind the cutting tool as it traversed the workpiece A mathematical spreadsheet model was used to predict the temperatures at the point measured by the pyrometer and at the point where cutting took placeFindings – It was found by selecting the “partition ratio” of the power being transmitted to the workpiece that agreement could be found between measured and predicted resultsResearch limitations/implications – The work was mainly carried out on aluminium samples, which exhibited low cutting temperaturesOriginality/value – The paper describes a method of finding the partition ratio of heat going into the workpiece