Quantitative Temperature Measurements Research Articles

Remote quantitative temperature and thickness measurements of plasma-deposited titanium nitride thin coatings on steel using a laser interferometric thermoreflectance optical thermometer

An optical thermometer based on the principle of laser thermoreflectance has been introduced to monitor the surface temperature of thin coatings on steel parts undergoing an industrial titanium nitride (TiN) alloy deposition process. To study the feasibility of the optical thermometer, various thermo-optical parameters of TiN affected by the deposition process have been investigated; namely, the reflectance-temperature relation, the thermoreflectance coefficient, and the coating thickness dependence of thermoreflectance and of total reflectance. A theory of interferometric thermoreflectance has been introduced to model the total reflectance variations during the coating process. An inverse reflectance-temperature relation for the TiN–D2 steel substrate system has been found and a first-order Taylor series expansion used to model thermoreflectance has been shown to yield a thermoreflectance coefficient which is independent of temperature. Both results are in quantitative agreement with the Drude–Zener theory of conductors and semi-conductors. An empirical formula has been derived to effectively model the experimental thermoreflectance coefficient dependence of the TiN–D2 steel system on TiN coating thickness, in qualitative agreement with scattering mechanisms of the Boltzmann transport theory in conductors and semiconductors. The good agreement of theoretical interferometric thermoreflectance simulations with in situ measurements during a specific industrial TiN sputter-coating growth process and the independence of the thermoreflectance and thin-coating-thickness reflectance coefficients from temperature show the potential of using this nonintrusive noncontacting technique as an optical thermometer to determine surface temperatures of physically inaccessible samples undergoing industrial coating deposition processes.

Temperature measurement from the Raman spectra of porous silicon

Raman spectra of porous silicon are obtained using 457.5nm laser line, from which some relations between peak parameters and laser powers are obtained. Our previous theoretical research demonstrated that the increase of laser power leads to the increase of local temperature, and this results in the shrink of local size which gives rise to the variation of a series of peak parameters. In this article we discuss and calculate in detail the influence of laser power on the local temperature of porous silicon, which set the experimental basis for the quantitative measurement of temperature utilizing Raman spectrum.

Visualization of dilute hydrogen jet flame in air flow

The structure of hydrogen jet flame diluted by CO$_2$ in air flow is studied by various visualization techniques, such as schlieren, direct photograph, tracer injection and reactive Mie scattering method, which allow understanding of the influence of CO$_2$ on the characteristics of the hydrogen jet flame. The experimental result indicates that the flame structure consists of laminar fuel jet and surrounding reaction zone near the nozzle exit. When the CO$_2$ fraction is increased, the width of the fuel jet grows and the reaction zone is reduced in size. These observations are further confirmed by quantitative measurements of temperature and velocity fields in the flame, which are evaluated by thermocouple and particle image velocimetry (PIV), respectively. These results indicate that the flame temperature is decreased and the flow rate of the fuel jet is increased by the influence of diluents, which are due to the reduced calorific value and larger density of fuel, respectively.

Quantitative measurement of temperature by proton resonance frequency shift at low field: a general method to correct non-linear spatial and temporal phase deformations

MRI thermometry methods are usually based on the temperature dependence of the proton resonance frequency. Unfortunately, these methods are very sensitive to the phase drift induced by the instability of the scanner which prevents any temperature mapping over long periods of time. A general method based on 3D spatial modelling of the phase drift as a function of time is presented. The MRI temperature measurements were validated on gel samples with uniform and constant temperature and with a linear temperature gradient. In the case of uniform temperature conditions, correction of the phase drift proved to be essential when long periods of acquisition were required, as bias could reach values of up to 200 °C in its absence. The temperature uncertainty measured by MRI was 1.2 °C in average over 290 min. This accuracy is coherent with the requirements for food applications especially when thermocouples are useless.

Quantitative multi-line NO-LIF temperature imaging

A novel temperature-imaging technique based on laser-induced fluorescence of nitric oxide is presented, analyzed and applied. Multi-line rotational thermometry is combined with an efficient spectra-fitting procedure in an imaging configuration. The technique is sensitive over a wide range of temperatures and robustly applicable to different steady combustion and flow systems. Application is shown in premixed and partially premixed ethylene/air Bunsen flames with equivalence ratios between 0.7 and 3.0, and the results are compared to coherent anti-Stokes Raman-scattering temperature measurements. The technique is robust against strong elastic scattering from soot in the rich flames. It yields absolute, quantitative temperature measurements without the necessity of external calibration.

Gas-phase temperature measurement in the vaporizing spray of a gasoline direct-injection injector by use of pure rotational coherent anti-Stokes Raman scattering

Pure rotational coherent anti-Stokes Raman spectroscopy is applied for quantitative gas-phase temperature measurements in the vaporizing spray of an automotive fuel injector. Interferences from elastically scattered stray light are greatly reduced by use of a polarization technique and spectral filtering in a double monochromator. The applicability of this technique to probing low-temperature sprays is successfully demonstrated.

Quantitative measurement of channel temperature of GaAs devices for reliable life-time prediction

The channel temperature of Gallium Arsenide (GaAs) devices was quantitatively measured using scanning thermal microscopy (SThM), which is a variation of atomic force microscopy (AFM). The temperature of the devices was also characterized by infrared (IR) imaging and thermal modeling. The measured SThM temperature values were close to the calculated values from the model, and were higher than those found by IR, as predicted. In contrast to most published AFM results which have reported only qualitative and indirect semi-quantitative thermal information about the sample, the results presented here can be used directly to determine accurately the device-temperature. These results are useful to the reliability community in that they help to predict a more accurate semiconductor device lifetime. By careful calibration of an AFM thermistor probe tip, a quantitative temperature measurement of the channel temperature of the GaAs PHEMTs and MESFETs can be made. The result of the measurement can be substantiated by applying a suitable thermal calculation, such as the Cooke model. A secondary measurement technique, such as IR microscopy, can also be useful in providing further information about the thermal response of the device. Published results using AFM techniques have been unable to determine the channel temperature quantitatively. The method in this paper applies to other types of electronic devices for which the channel (or junction) temperature can be probed from the top surface of the device.

Quantitative Interferometry in the Severe Acoustic Environment of Resonant Supersonic Jets

Understanding fundamental fluidic dynamic and acoustic processes in high-speed jets requires quantitative velocity, density and temperature measurements. In this paper we demonstrate a new, robust Liquid Crystal Point Diffraction Interferometer (LCPDI) that includes phase stepping and can provide accurate data even in the presence of intense acoustic fields. This novel common path interferometer (LCPDI) was developed to overcome difficulties with the Mach Zehnder interferometer in vibratory environments and is applied here to the case of a supersonic shock- containing jet. The environmentally insensitive LCPDI that is easy to align and capable of measuring optical wavefronts with high accuracy is briefly described, then integrated line of sight density data from the LCPDI for two underexpanded jets are presented.

Microscale temperature measurement by scanning thermal microscopy

Scanning thermal microscopy (SThM) can measure thermal image with a nano-scale spatial resolution. However, there remains an issue in quantitative temperature measurement. We proposed an active temperature measurement method that provides a real temperature image by compensating a variation in contact thermal conductance. Performance of the active method was examined by a multi-function cantilever made with micro-fabrication process. Response test of the cantilever showed about 50 Hz cut off frequency for both passive and active method. Temperature measurement test indicated that sensitivity of heat flow detection was not enough to measure real temperature regardless of the thermal contact conductance. Imaging test demonstrated that the active method takes temperature image closer to real temperature distribution than the passive method.

C134 零位式放射温度計測システムの開発 : 測定原理の検証と MEMS 複合センサの試作

A novel radiation temperature measurement method was invented. In the traditional radiation thermometry, an emissivity data of a sample is necessary for converting the detected radiation intensity into temperature with a particular calibration curve. On the other hand, temperature of the sample can be decided by finding the sensor temperature at which the radiation intensity is null in our method. Introduction of the null method into radiation thermometry eliminates the need for the emissivity value. The principle of the method was verified with a measurement system where a heater-equipped commercial thermopile device was driven with a thermal feedback circuit. Quantitative temperature measurement was achieved for the flat brass surface with black paint or with plastic tape. Furthermore, a integrated radiation sensor having a cantilever type thermopile, electric heater and thermocouple was made by the silicon micro-fabrication technology. Measurement test with the sensor showed that the method absorbs the difference in emissivity, and that local temperature distribution in the sensor influences the detection of radiation intensity.

二色LIF感温粒子を用いた三次元温度速度同時計測

A temperature sensitive particle, which can be utilized for the three-dimensional simultaneous measurement of velocity and temperature, has been developed by introducing two fluorescent dyes into the microparticle and its thermo-optical characteristics are quantified. Even though the particle involving a fluorescent substance inside has the temperature sensitivity according to the LIF technique, the intensity of the fluorescence also depends upon the size of the particle and the intensity of the excitation light and thus the multiple-point temperature measurement with this particle was not very easy. Presently, by introducing two fluorescent materials with different temperature sensitivities into the particle, the quantitative temperature measurements with different sizes of particles can now be performed. A three-dimensional simultaneous measurement of velocity and temperature in the turbulent natural convection layer has also been carried out by introducing the two-color LIF particles. The results of the temperature measurement showed a reasonable agreement with DNS data.

Quantitative interferometry in the severe acoustic environment of resonant supersonic jets

There is renewed interest in the study of supersonic jets due to advances in high speed jet propulsion, supersonic combustion, and jet noise suppression for the next generation supersonic commercial transport. Understanding fundamental fluid dynamic and acoustic processes for these applications requires quantitative velocity, density and temperature measurements. In this paper we present data demonstrating a new, robust interferometer that can provide accurate data even in the presence of intense acoustic fields. This novel interferometer, the Liquid Crystal Point Diffraction Interferometer (LCPDI), was developed earlier for space flight experiments and is applied here to the case of a supersonic shock-containing jet. The LCPDI is briefly described, then integrated line-of-sight density data from the LCPDI for two underexpanded free jets are presented. The experimental shock spacings agree well with theory.

Liquid crystal quantitative temperature measurement technique

Quantitative temperature measurement using wide band thermochromic liquid crystals is an “area” thermal measurement technique. This technique utilizes the feature that liquid crystal changes its reflex light color with variation of temperature and applies an image capturing and processing system to calibrate the characteristic curve of liquid crystal’s color-temperature. Afterwards, the technique uses this curve to measure the distribution of temperature on experimental model. In this paper, firstly, each part of quantitative temperature measurement system using liquid crystal is illustrated and discussed. Then the technique is employed in a long duration hypersonic wind tunnel, and the quantitative result of the heat transfer coefficient along laminar plate is obtained. Additionally, some qualitative results are also given. In the end, comparing the experimental results with reference enthalpy theoretical results, a conclusion of thermal measurement accuracy is drawn.

Mixing Characteristics of Axisymmetric Free Jets From a Contoured Nozzle, an Orifice Plate and a Pipe

The differences in mixing performance between axisymmetric turbulent jets issuing from three common types of nozzle, viz. a contoured (or smooth contraction) nozzle, a sharp-edged orifice and a long pipe, are investigated. The investigation is carried out using both qualitative flow visualizations and quantitative measurements of the centerline passive temperature. It is revealed that the jet issuing from an orifice plate provides the greatest rate of mixing with ambient fluid, while the pipe jet has the lowest rate. Physical insight into the differences is explored using a planar imaging technique and measurements of power spectra of the fluctuating velocity.

Proposal of quantitative temperature measurement using two-color technique combined with several infrared radiometers having different detection wavelength bands

Infrared thermography has been widely used to visualize a two-dimensional temperature field for various engineering applications. However, in general, conventional infrared thermography cannot directly be applied to quantitative temperature measurement on glossy metal surfaces under near-ambient conditions, because of the severe influ- ence of the reflected energy incident from the surroundings on the mea- surement. When it is necessary to measure the temperature quantita- tively, an appropriate calibration involving complicated procedures must be performed. In this paper, therefore, a new technique of measuring temperature is proposed for near-ambient conditions, by combining si- multaneously several infrared radiometers having different detection wavelength bands to enable a two-color technique, which does not re- quire any temperature calibrations. The sensors concerned have a se- lective wavelength band of several micrometers in width in the range of 2 to 13 mm. The applicability of the method, including a series of proposed equations, has been confirmed by an investigation; the numerical simu- lation presented merely allows a parametric study of how the result var- ies for different values of emissivity corresponding to a pair of infrared radiometers. An experimental investigation is also performed to estimate or correct the measurement error pertaining to the present technique. This technique has the feature that a two-dimensional temperature field can be evaluated quantitatively, nondestructively, and simultaneously at each picture element without presuming any emissivity and reflectivity, even though the object has a complicated shape; so that it may be useful in various medical or engineering applications. © 2001 Society of Photo-

On the proposal of quantitative temperature measurement by using three-color technique combined with several infrared sensors having different detection wavelength bands

We developed the previous infrared sensing technique, the two-color technique, to establish further a more general technique to measure the temperature quantitatively under near-ambient conditions. The quantitative temperature measurement, three-color technique, was newly proposed by combining three kinds of infrared radiometers having different detection wavelength bands. The measurement can also be done by adding three infrared filters to one infrared radiometer. The radiometers have a selective detection wavelength band of several μm in width which is in the range of 2–13 μ m. The method was confirmed using numerical simulation to allow a parametric study of how the result varies for different values of emissivity corresponding to the respective infrared radiometers. An experimental investigation was also performed to evaluate the measurement error and the adaptability of the technique. As this technique has a feature that can perform quantitative temperature measurement for objective surfaces at each picture element without presuming any emissivity, reflectivity and ambient conditions, there is a possibility that the technique will be useful for various medical or engineering disciplines.

Multipoint temperature and oxygen-concentration measurements using rotational coherent anti-Stokes Raman spectroscopy

A novel technique for coherent anti-Stokes Raman spectroscopy (CARS) measurements in multiple points is presented. With a system of cylindrical lenses, each laser beam is split into several focused beams, yielding separate planar boxcars configurations. Spectrally resolved CARS signals are detected at different heights on the CCD chip. With dual-broadband rotational CARS the setup is demonstrated for quantitative measurements of temperature- and oxygen-concentration profiles. The technique was demonstrated for three points only, but it can be extended to more points by use of special optics; this choice must be based on a sufficient signal-to-noise ratio in all points for the actual measurement condition.

Experimental Investigation of Shear Coaxial Cryogenic Jet Flames

Abstract: This paper reports results from experiments carried out on the jet name formed from a single coaxial injector. This device was fed with Liquid oxygen and gaseous hydrogen and placed in a chamber equipped with quartz windows. The flame is observed with a set of optical methods: light emission from OH radicals, laser-induced fluorescence of OH and O-2, elastic, and Raman scattering from the liquid-oxygen jet. These techniques are used to obtain images of the name zone. It is then possible to deduce the name location with respect to the liquid jet from simultaneous elastic scattering and laser-induced fluorescence of OH measurements. Average emission images treated with Abel's transform provide the local volumetric light emission from OH radicals, This yields the mean flame structure and constitutes a different method for locating the flame. The images obtained by exciting the fluorescence of O-2 provide complementary information on the flame shape and they may be used to estimate the local reaction rate. Quantitative temperature measurements based on coherent anti-Stokes Raman scattering from H-2 give additional dues on the combustion zone. These data may be used to develop a unified picture of the name in the vicinity of the injection plane.

On the Proposal of Quantitative Temperature Measurement Using Two-colored Technique Combined with Several Infrared Radiometers Having Different Wavelength Bands.

Infrared Thermography has been widely used to visualize a two-dimensional temperature field for various engineering applications. In general, the conventional technique can not be directly applied to quantitative temperature measurement for glossy metal surfaces under near-ambient conditions because the influence of the reflected energy becomes severe on the temperature measurement. When necessary to measure temperature quantitatively, an appropriate calibration having complicated formalities should be performed. In this paper, therefore, a technique of measuring temperature is proposed under near-ambient conditions by combining several infrared radiometers having different wavelength bands to make the two-colored technique which is not needed to practice any temperature calibrations. The respective sensors concerned have a selective wavelength of several μm in width in the range of 2∼13μm. The applicability including a series of equations proposed is confirmed using the numerical simulation merely to allow a parametric study of how the result varies for different values of emissivity indicated with a pair of infrared radiometers. The experimental investigation is also performed to estimate a measurement error of the technique proposed. The technique has a feature that we can perform quantitative temperature measurement without presuming any emissivity and reflectivity.

Three-Dimensional Temperature Measurement by Liquid Crystal Thermometry and Its Application to the Study of Turbulent Thermal Convection.

A new calibration technique of liquid crystal thermometry has been introduced to the quantitative measurement of temperature in a thermal fluid and applied to the study of turbulent thermal convection. The present calibration technique improves the accuracy of temperature measurement in comparison with the classical calibration technique with hue. Three-dimensional temperature measurement of turbulent thermal convection over a horizontal smooth surface is carried out at a flux Rayleigh number of 3×109 by scanning a light sheet normal to the image plane and capturing a number of sequential visualized images. The spatial temperature distributions of thermal plumes over a horizontal surface are demonstrated by the reconstruction of isothermal contour surfaces and various cross-sectional views of the plumes. These results indicate the presence of a polygonal cell structure close to the surface and the generation of plumes at the intersections of high-temperature lines.