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Aluminum is used in the composition of many high explosives and contributes to their blast effect. This work focuses on the study of the combustion of a single isolated particle of size between 30 and 100 µm in an arbitrary atmosphere, whose pressure and composition are chosen to be close to those encountered in a high-explosive fireball. This gaseous atmosphere is still largely unreferenced, and this work aims to provide a better understanding of combustion in this environment. The use of an electrostatic levitator coupled with multi-spectral pyrometric diagnostics enables us to select a single particle and measure its temperature during combustion. Photomultipliers (PMs) are used to follow the temporal evolution of the particle's light emission during combustion. In this work, we also used PMs as pyrometric devices to measure temperature. The diagnostic allows us to determine the temporal evolution of the integrated temperature of the condensed phase during combustion of the aluminum particle. By way of example, a temperature of 3300K was obtained for the combustion of Al in air at 1 bar. The data collected will also be used to verify the assumptions made in the combustion models (e.g. temperature stability during combustion). [ABSTRACT FROM AUTHOR]

Measure of temperature dynamics in induction sealing processes is of paramount importance for the validation of physics-based models. In this work, commonly used commercial tools for temperature measurements, such as thermocouples, pyrometers and thermal cameras, are benchmarked for the characterization of the temperature dynamics occurring in multilayer aluminum foil-based packaging material undergoing relatively fast (i.e., ×100 ms) induction heating transients. [ABSTRACT FROM AUTHOR]

The terms heat and temperature are two distinct but closely related concepts. The core difference between heat and temperature is that heat deals with thermal energy, whereas temperature is more concerned with molecular kinetic energy. As a substance is cooled, it loses thermal energy. Eventually it will reach a temperature at which it no longer possesses any thermal or kinetic energy and so it can no longer be cooled; this temperature is absolute zero. Another unique temperature concept is the triple point of a substance; the temperature at which a substance exists simultaneously and in perfect equilibrium in a solid, liquid and gaseous phase. The triple point is unique for every substance; for water, it reaches its triple point at 0.01°C at a pressure of 0.006 atmospheres. Temperature may be measured using the Celsius, Fahrenheit and Kelvin scales. Many clinical thermometers are designed to display the output in a digital format to enable easier monitoring as well as recording. Non-electrical thermometers are still in use today. Thermoregulation in the anaesthetized patient is achieved by the understanding of the mechanisms of heat loss, as well as the use of thermometers, warming and cooling devices. [ABSTRACT FROM AUTHOR]

The modeling of machining process characteristics and, in particular, of various cutting processes occupies a significant part of modern research. Determining the thermal characteristics in short hole drilling processes by numerical simulation is the object of the present study. For different contact conditions of the workpiece with the drill cutting inserts, the thermal properties of the machined material were determined. The above-mentioned properties and parameters of the model components were established using a three-dimensional finite element model of orthogonal cutting. Determination of the generalized values of the machined material thermal properties was performed by finding the set intersection of individual properties values using a previously developed software algorithm. A comparison of experimental and simulated values of cutting temperature in the workpiece points located at different distances from the drilled hole surface and on the lateral clearance face of the drill outer cutting insert shows the validity of the developed numerical model for drilling short holes. The difference between simulated and measured temperature values did not exceed 22.4% in the whole range of the studied cutting modes. [ABSTRACT FROM AUTHOR]

Infrared radiation thermometers (IRTs) overcome many of the limitations of thermocouples, particularly responsiveness and calibration drift. The main challenge with radiation thermometry is the fast and reliable measurement of temperatures close to room temperature. A new IRT which is sensitive to wavelengths between 3 μm and 11 μm was developed and tested in a laboratory setting. It is based on an uncooled indium arsenide antimony (InAsSb) photodiode, a transimpedance amplifier, and a silver halogenide fibre optic cable transmissive in the mid- to long-wave infrared region. The prototype IRT was capable of measuring temperatures between 35 °C and 100 °C at an integration time of 5 ms and a temperature range between 40 °C and 100 °C at an integration time of 1 ms, with a root mean square (RMS) noise level of less than 0.5 °C. The thermometer was calibrated against Planck's law using a five-point calibration, leading to a measurement uncertainty within ±1.5 °C over the aforementioned temperature range. The thermometer was tested against a thermocouple during drilling operations of polyether ether ketone (PEEK) plastic to measure the temperature of the drill bit during the material removal process. Future versions of the thermometer are intended to be used as a thermocouple replacement in high-speed, near-ambient temperature measurement applications, such as electric motor condition monitoring; battery protection; and machining of polymers and composite materials, such as carbon-fibre-reinforced plastic (CFRP). [ABSTRACT FROM AUTHOR]

This article presents a new model of optical power gathered by a fiber-optic pyrometer when there is a tilting angle between the fiber longitudinal axis and the vector perpendicular to the tangent plane of the emitted surface. This optical power depends on the fiber specifications, such as the diameter and the numerical aperture (NA), as well as the object parameters, including its diameter, emissivity, and tilting angle. Some simulations are carried out using other pyrometers from the literature without tilting to validate the model. Additional simulations with different optical fibers, object sizes, and distances at different tilting angles allow us to describe the behavior of the pyrometer when the object is smaller than the optical fiber field of view (the light cone defined by its NA). The results show that for a finite surface object, the power collected by the optical fiber is affected by changes in the tilting angle, greater tilting lesser gathered power, and reaching the maximum power when the field of view of the fiber covers up the entire object, as expected. On the other hand, additional equations are presented to describe the maximum tilting angle, and distance that allow the maximum power gathered for a determined object diameter and fiber, avoiding temperature measurement errors. [ABSTRACT FROM AUTHOR]

The Fourier transform infrared (FTIR) spectrometer is widely used for spectrum analysis and radiation intensity measurement. In this work, a pyrometer with the temperature measurement range of 800°C to 1200°C is developed based on the FTIR spectrometer, and the calibration of the instrument coefficients using a standard radiation source is performed. On this basis, the readout noise and shot noise in the spectral signal are analyzed, and a detailed quantitative evaluation of the influences of two kinds of noise on the temperature measurement accuracy is also carried out in this work. Experimental results show that the temperature deviation caused by the two kinds of noise is less than 1°C when the wavelength is within the range of 2.0 to 5.4 μm. However, when the wavelength is greater than 5.4 μm, the maximum temperature deviation caused by the readout noise and shot noise can reach about 12°C and 18°C, respectively. In view of this, a Kalman filter method is introduced in this work to reduce temperature fluctuations caused by these noises, where the maximum fluctuation can be reduced from 83.9°C to 6.1°C with this filter method. These experimental results can provide a valuable guidance for the general-purpose calibration and assessment of the FTIR-based pyrometer. [ABSTRACT FROM AUTHOR]

A combined optical fiber instrument combined with a pyrometer (hereinafter referred to as an optical fiber instrument) is designed for the implementation of highintensity laser thermotherapy, HIL therapy, laser therapy, photodynamic therapy, etc. with the function of dynamic real-time temperature monitoring. The design of the fiber-optic instrument allows it to be used in combination with diode surgical laser devices during the treatment of traumatized, wounded and sick people. [ABSTRACT FROM AUTHOR]

We proposed the determination method of the normal spectral emissivity of molten oxides using a combination of immiscible molten oxides and liquid metals. We can determine the normal spectral emissivity of molten oxide from the ratio of the normal spectral radiance of molten oxides and liquid metals. using a commercially available pyrometer combined with an electromagnetic levitation system. In the present study, we measured the normal spectral emissivity of a molten oxide sample from SiO2-CaOFeO (SCF) ternary system and FeO using liquid Fe as the reference liquid metal. The normal spectral emissivity of the molten SCF sample with the composition of SiO2:CaO:FeO = 20:20:60 mass % was determined to be 0.78 * 0.01 and that of molten FeO to be 0.68 * 0.03. Based on these results. we have discussed the relationship between the normal spectral emissivity and the electrical conductivity of molten oxides. [ABSTRACT FROM AUTHOR]

The purpose of the work is to propose methods and means for determining the technical condition of fuel equipment. A method is proposed for determining the technical condition of the high-pressure pump and injectors of the marine diesel MAN B&W 6S50MC-C by changing the maximum fuel pressure and temperature of the outer surface of the pipeline. For fuel equipment with a maximum pressure in the pipeline from 50 to 150 MPa, the permissible pressure change zone is determined. A formula is proposed that additionally takes into account the cyclic fuel supply and its mass when estimating the temperature from its compression by the pump plunger. The fuel temperature during compression is determined depending on the pressure value. The calculation of the heat transfer process through the pipeline wall and from the heated wall surface to the air is performed. A portable RGK PL12 pyrometer is proposed to measure the temperature on the pipeline surface and determine the technical condition of the fuel equipment. The permissible temperature change zone of the pipeline surface is given, according to which the serviceable condition of the pump and the nozzle is evaluated.

Accurate and high-speed transient surface-temperature measurements of combustion devices including internal combustion (IC) engines, gas turbines, etc., provide validation targets and boundary conditions for computational fluid dynamics models, and are broadly relevant to technology advancements such as performance improvement and emissions reduction. Development and demonstration of a multi-infrared-channel pyrometry-based optical instrument for high-speed surface-temperature measurement is described. The measurement principle is based on multi-spectral radiation thermometry (MRT) and uses surface thermal radiation at four discrete spectral regions and a corresponding emissivity model to obtain surface temperature via non-linear least squares (NLLS) optimization. Rules of thumb for specifying the spectral regions and considerations to avoid interference with common combustion products are developed; the impact of these along with linear and non-linear MRT analysis are assessed as a function of temperature and signal-to-noise ratio. A multi-start method to determine the MRT-solution global optimum is described and demonstrated. The resulting multi-channel transient pyrometry instrument is described along with practical considerations including optical-alignment drift, matching intra-channel transient response, and solution-confidence indicators. The instrument demonstrated excellent >97% accuracy and >99% 2-sigma precision over the 400–800 °C range, with ~20 µs (50 kHz, equivalent to 0.2 cad at 2000 RPM IC-engine operation) transient response in the bench validation. [ABSTRACT FROM AUTHOR]

A linear pyrometer is used to realize the International Temperature Scale of 1990 (ITS-90) for temperature ranges above 961.78 °C in most National Metrology Institute (NMI) radiation thermometry labs. The different components of the linear pyrometer system working together to measure temperature may exhibit some errors which should be accounted for. The errors can be characterized by several equipment parameters that should be measured before the radiation thermometer is used to realize ITS-90 temperatures. Relative spectral responsivity (s), size of source effect (SSE), gain ratio (GR), non-linearity (NL), distance effect (DE), temperature coefficient and zero drift are all major equipment parameters that characterize the efficiency of a linear pyrometer in realizing ITS-90. In this work, an attempt was made to describe and demonstrate these major parameters by using actual measured characterization results of a linear pyrometer. Uncertainty contributions from some of the parameters considered in scale realizations was also demonstrated using the measurement results. [ABSTRACT FROM AUTHOR]

Infrared radiation thermometers (IRTs) overcome many of the limitations of thermocouples, particularly responsiveness and calibration drift. The main challenge with radiation thermometry is the fast and reliable measurement of temperatures close to room temperature. A new IRT which is sensitive to wavelengths between 3 μm and 11 μm was developed and tested in a laboratory setting. It is based on an uncooled indium arsenide antimony (InAsSb) photodiode, a transimpedance amplifier, and a silver halogenide fibre optic cable transmissive in the mid- to long-wave infrared region. The prototype IRT was capable of measuring temperatures between 35 °C and 100 °C at an integration time of 5 ms and a temperature range between 40 °C and 100 °C at an integration time of 1 ms, with a root mean square (RMS) noise level of less than 0.5 °C. The thermometer was calibrated against Planck’s law using a five-point calibration, leading to a measurement uncertainty within ±1.5 °C over the aforementioned temperature range. The thermometer was tested against a thermocouple during drilling operations of polyether ether ketone (PEEK) plastic to measure the temperature of the drill bit during the material removal process. Future versions of the thermometer are intended to be used as a thermocouple replacement in high-speed, near-ambient temperature measurement applications, such as electric motor condition monitoring; battery protection; and machining of polymers and composite materials, such as carbon-fibre-reinforced plastic (CFRP).

A pyrometer with non-parallel sighting is developed, which allows simultaneously with temperature measurement to perform video surveillance of the control object. Pyrometer has optically connected lens, signal meter, thermostat in which radiation receiver is placed, and video camera. The front surface of the thermostat is polished, directed at an angle of 45 ° to the optical axis of the lens and has a hole that acts as a field diaphragm. Video camera is directed to polished surface of thermostat perpendicular to optical axis of lens. Pyrometer operation, its design and functional diagram are described.

Process online monitoring is a vital and integral part of high-speed laser scribing process in which speed and quality are paramount. In this study, a multi-sensory platform for real-time monitoring of the ultrafast pulsed laser engraving process has been developed. Four different sensors have been examined from various perspectives and the results have been analyzed and compared. The real-time monitoring system developed for this study consisted of IPG ytterbium pulsed fiber laser, scan head, illumination system, and four monitoring sensors, including a spectrometer, pyrometer, infrared (IR) camera, and high-speed camera. Various experiments were performed to evaluate the performance of the designed platform by applying each sensor to monitor a high-speed laser scribing process in real-time. The output of each sensor was analyzed by changing different laser and process parameters, such as laser power, focal position, beam speed, and pulse length. Strengths, weaknesses, and challenges of using each monitoring tool for the laser engraving process were discussed based on the obtained results.

This article presents a new model of optical power gathered by a fiber-optic pyrometer when there is a tilting angle between the fiber longitudinal axis and the vector perpendicular to the tangent plane of the emitted surface. This optical power depends on the fiber specifications, such as the diameter and the numerical aperture (NA), as well as the object parameters, including its diameter, emissivity, and tilting angle. Some simulations are carried out using other pyrometers from the literature without tilting to validate the model. Additional simulations with different optical fibers, object sizes, and distances at different tilting angles allow us to describe the behavior of the pyrometer when the object is smaller than the optical fiber field of view (the light cone defined by its NA). The results show that for a finite surface object, the power collected by the optical fiber is affected by changes in the tilting angle, greater tilting lesser gathered power, and reaching the maximum power when the field of view of the fiber covers up the entire object, as expected. On the other hand, additional equations are presented to describe the maximum tilting angle, and distance that allow the maximum power gathered for a determined object diameter and fiber, avoiding temperature measurement errors.

The article discusses the issues of improving strainresistive pressure sensors (PS) for their joint use with modern achievements of fiber optics (FO). The possibilities of implementation and features of FO pyrometric compensation of the temperature error of semiconductor and resistive strain-resistor, optical and/or electrical heating of the strain gage for selfcalibration of the pyrometer, power supply by optical radiation transmitted through a light guide with galvanic isolation of the PS circuit, increased noise reduction and fire and explosion safety are considered. Noise properties of semiconductor and resistive strainresistor are also considered.

Perkembangan teknologi berbasis internet yang pesat menyebabkan terjadinya perubahan pada sektor industri yang dikenal dengan Revolusi Industri 4.0. Industri manufaktur pengecoran merupakan salah satu sektor industri yang harus beradaptasi dengan perkembangan industri 4.0 agar dapat bersaing dalam meningkatkan kualitas produk coran. Beberapa parameter yang mempengaruhi kualitas produk coran adalah temperatur saat penuangan (pouring) dan laju penuangan. Penentuan temperatur penuangan harus memperhitungkan faktor kehilangan panas yang disebabkan oleh waktu pemindahan logam cair dan kondisi lingkungan sekitar. Penentuan temperatur tuang yang kurang tepat dapat menyebabkan terbentuknya porositas (rongga) pada produk hasil pengecoran. Karena pentingnya penentuan temperatur tersebut, maka pada penelitian ini dibangun sistem monitoring berbasis internet of things (IoT) untuk memantau temperatur logam cair saat proses pengecoran secara real-time. Sistem yang dibangun terdiri atas tiga bagian, yaitu: sensor temperatur, gateway dan server. Perangkat pyrometer digunakan untuk mengukur temperatur logam cair dan mengirimkannya ke gateway. Perangkat gateway kemudian mengirimkan data tersebut ke server. Pengguna dapat mengamati temperatur logam cair secara real-time melalui website. Hasil penelitian menunjukkan bahwa dengan sistem monitoring berbasis IoT ini, dapat diperoleh database pengukuran temperatur logam cair yang optimal. Tingkat keakuratan pengukuran data temperatur tersebut mencapai 99,5%.

The uncertainty of emissivity has a major effect on the accuracy of a pyrometer in billet temperature measurement. In order to eliminate the influence of emissivity, we place a reflector with two apertures at the front of a pyrometer. The two apertures on the reflector are used to measure intrinsic radiation and approximate blackbody radiation of the billet. The radiation is collected by two infrared dual-band detectors in the pyrometer. Then, the real-time emissivity of the billet can be measured with no assumptions, so the influence of emissivity is eliminated. In addition, the measurement uncertainty is analyzed based on the ray-tracing method. The pyrometer is developed and the accuracy verification of emissivity is implemented. Compared with the reference material at the same temperature, the measurement errors of the emissivity are 0.021 and 0.005 at two wavelengths. Then, we install the pyrometer in the medium plate rolling process for measurement. Compared with a thermal imager used in the rolling process, the measurement fluctuation is reduced obviously. It indicates that the method of emissivity measurement is very effective for billet temperature measurement. [ABSTRACT FROM AUTHOR]

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

While the simultaneous scanning measurement and temperature field reconstruction of multiple aero-engine turbine components are extremely important for engine condition monitoring and parameter control, it is currently difficult to achieve. This study proposed a panoramic scanning optical pyrometer with circumferential and radial scan ranges of 0°–360° and 0–80 mm, respectively. Moreover, an innovative 2-D temperature field reconstruction algorithm based on panoramic scanning was proposed. After the temperature calibration of the pyrometer, the steady-state temperature measurement error was less than 1.6 °C, and the transient temperature measurement error was less than 2.5 °C. Furthermore, scanning measurement experiments were performed to verify the uncertainty of the 2-D temperature field reconstruction algorithm and the panoramic reconstruction function of the proposed pyrometer. [ABSTRACT FROM AUTHOR]

The present article investigates possibilities for increasing the accuracy of non-contact temperature measurements. The proposed surface pyrometry method uses mobile reflective screens to reduce errors caused by background radiation from third-party emitters. The temperature measurements were carried out by a commercially-available narrow-angle pyrometer, sighted at the surface through a hole in the cavity of a screen made of a fibrous heat-resistant material. The results of experiments substantiating the content and parameters of the measurement method operations are presented. In particular, a decrease in the actual temperature of the measured surface by approximately 20–25°C was noted during the installation of uncooled screens into the chamber of the thermal unit prior each measurement. Qualitative results of measuring the surface temperature were obtained under conditions when the screens were in the furnace working space between measurements behind held for 1–2 min in positions on the surface for temperature leveling, first next to, then directly above the place of temperature measurement. The results of testing the measurement method in industrial conditions are described. This method can be used for technological measurements directly in high-temperature units or for periodic testing and determination of corrections to the readings of stationary pyrometers. [ABSTRACT FROM AUTHOR]

The article presents the analysis of uncertainties associated with reliable accounting difficulties for the radiation coefficient in non-contact temperature measurement in industrial environment. Practical recommendations of methodological and instrumental nature to reduce such measurements errors are offered. On the Planck function and the aluminum reflection coefficient mathematical model basis the analytical aluminum radiation coefficient dependence on temperature and wavelength is obtained. Methodological errors estimates of low-temperature thermometers with a spectral sensitivity ranges equal to 7–14 and 3–5 µm are produced. Experimental studies are carried out using Optris CT LT15 pyrometer and Flir E60 infrared imager.

The quality of the material deposition and contour accuracy produced by WAAM (Wire Arc Additive Manufacturing) depends on process parameters such as the temperature and the volume of the weld pool. The control of the welding process can be substantially improved by obtaining real-time signals of the weld-pool temperature and volume. In this paper, we present a new optical sensor that can measure the quantities through the welding arc. We have developed a ratio pyrometer with narrowband filters that suppresses the radiation from the plasma. We present our new sensor in this paper and demonstrate its capability to measure the weld-pool temperature pyrometrically and the weld-pool area by digital image processing as a real-time signal through the arc. In addition, we estimate the weld-pool volume from its area and the known material inflow.

Accurate and high-speed transient surface-temperature measurements of combustion devices including internal combustion (IC) engines, gas turbines, etc., provide validation targets and boundary conditions for computational fluid dynamics models, and are broadly relevant to technology advancements such as performance improvement and emissions reduction. Development and demonstration of a multi-infrared-channel pyrometry-based optical instrument for high-speed surface-temperature measurement is described. The measurement principle is based on multi-spectral radiation thermometry (MRT) and uses surface thermal radiation at four discrete spectral regions and a corresponding emissivity model to obtain surface temperature via non-linear least squares (NLLS) optimization. Rules of thumb for specifying the spectral regions and considerations to avoid interference with common combustion products are developed; the impact of these along with linear and non-linear MRT analysis are assessed as a function of temperature and signal-to-noise ratio. A multi-start method to determine the MRT-solution global optimum is described and demonstrated. The resulting multi-channel transient pyrometry instrument is described along with practical considerations including optical-alignment drift, matching intra-channel transient response, and solution-confidence indicators. The instrument demonstrated excellent >97% accuracy and >99% 2-sigma precision over the 400–800 °C range, with ~20 µs (50 kHz, equivalent to 0.2 cad at 2000 RPM IC-engine operation) transient response in the bench validation.

Copyright of Technisches Messen is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The uncertainty of emissivity has a major effect on the accuracy of a pyrometer in billet temperature measurement. In order to eliminate the influence of emissivity, we place a reflector with two apertures at the front of a pyrometer. The two apertures on the reflector are used to measure intrinsic radiation and approximate blackbody radiation of the billet. The radiation is collected by two infrared dual-band detectors in the pyrometer. Then, the real-time emissivity of the billet can be measured with no assumptions, so the influence of emissivity is eliminated. In addition, the measurement uncertainty is analyzed based on the ray-tracing method. The pyrometer is developed and the accuracy verification of emissivity is implemented. Compared with the reference material at the same temperature, the measurement errors of the emissivity are 0.021 and 0.005 at two wavelengths. Then, we install the pyrometer in the medium plate rolling process for measurement. Compared with a thermal imager used in the rolling process, the measurement fluctuation is reduced obviously. It indicates that the method of emissivity measurement is very effective for billet temperature measurement.

The American oil revolution of 1859 and the invention of a kerosene lamp contributed to the onset of the kerosene era when candle lighting was replaced by kerosene. The side effect of this was the growth of fires and explosions due to the use of unsafe kerosene. There was a need to develop criteria for safe kerosene. The fire (burning) and flash point of kerosene were chosen as such indicators. The first stage of creating instruments to determine these indicators began in 1862 and ended at the beginning of the 20th century. This stage is characterized by the development of apparatuses of various designs, among them were vapor testers. The first naphthometers (Salleron-Urbain, Vander Weyde, Blair, Meusel, Byasson, Geissler, Liebermann, Stoddard, Beilstein, Mack, Bernstein, Braun, Wright, Meyer, Meyer–Hörler, Haass, Abelianz and Bradley–Hale) are considered in the article. These devices have not survived to our days and are undeservedly forgotten, however, the ideas embodied in their principle of operation are being successfully used at present. [ABSTRACT FROM AUTHOR]

To solve an important problem associated with the provision of technological processes with modern temperature measurement tools, specific requirements were formulated with respect to the optical part of a pyrometer intended for measuring temperature in the measurement cavity of the tungsten–rhenium thermocouple calibration setup (up to 2200°С). In accordance with these requirements, the optical part of a commercial Termokont pyrometer has been reworked and experimentally tested. [ABSTRACT FROM AUTHOR]

Copyright of Revista Iberoamericana de Ingeniería Mecánica is the property of Editorial UNED and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper describes the development of cutting temperature measurement of end mill tool by using infrared radiation technique approach. Compared to conventional thermocouple technique, infrared radiation technique is an advance method of measuring temperature which featured high accuracy, high response rate, wide range of temperature scale detection and almost compatible with all materials used in the manufacturing industry. We measures the emission of infrared radiation from the source, which is cutting edge of tool by using photocells that contains InAs and InSb photovoltaic detectors. Photocells converts the infrared radiation to a voltage signal and then recorded by oscilloscope followed with a calibration with its corresponding temperature. This paper discussed about the calibration method, cutting experiment setup, the limit of infrared radiation level detected by photocells, signal correction of output signal, and relations of peak signal formation with rotation of end mill tool. The developed pyrometer is also capable to profile the cutting tool’s rotation based on the movements of infrared radiation’s emission at cutting tool’s edge. The conclusion was that the measurement of cutting temperature of high speed machining by using infrared radiation technique is possible. The developed pyrometer are capable to detect temperature changes at a span of 0.01 ms.

The article deals with the use of jet-drop optical measuring systems (JDOMS) on machine tools for recording acoustic emission (AE) signals and pyrometric temperature measurement in the cutting zone. The work of JDOMS is considered on the examples of metal working with the supply to the cutting zone of cutting coolant directed by a jet or through the internal through-holes of the cutting tool. It is shown that the coolant flow is used for directional transmission from the cutting zone of AE signals to the hydrophone as a sound guide and light of the infrared range to the pyrometer as a light guide. In the first case, AE signals are recorded to control the metal working conditions in the cutting zone, and in the second case, its temperature is measured.

The American oil revolution of 1859 and the invention of a kerosene lamp contributed to the onset of the kerosene era when candle lighting was replaced by kerosene. The side effect of this was the growth of fires and explosions due to the use of unsafe kerosene. There was a need to develop criteria for safe kerosene. The fire (burning) and flash point of kerosene were chosen as such indicators. The first stage of creating instruments to determine these indicators began in 1862 and ended at the beginning of the 20th century. This stage is characterized by the development of apparatuses of various designs, one of which were "semiclosed" testers. The first naphthometers (by Smith–Jones, Parrish, Biel, Granier, Tagliabue, Elliott, Wisconsin, Foster, Luchaire, Millspaugh, Skalweit, Parrish-Engler, Engler, Heumann Leybold, Braun, Mann, Saybolt and Ehrenberg) are considered in the article. Many of these devices have not survived to our days and are undeservedly forgotten. [ABSTRACT FROM AUTHOR]

The American oil revolution of 1859 and the invention of a kerosene lamp contributed to the onset of the kerosene era when candle lighting was replaced by kerosene. The side effect of this was the growth of fires and explosions due to the use of unsafe kerosene. There was a need to develop criteria for safe kerosene. The fire (burning) and flash point of kerosene were chosen as such indicators. The first stage of creating instruments to determine these indicators began in 1862 and ended at the beginning of the 20th century. This stage is characterized by the development of apparatuses of various designs, one of which were "open cup" testers. The first naphthometers (by Abel, Tag, Pease, Shaw, Saybolt, Pinkney, Squier, Indiana state, Millochau, Ettele, Cleveland, Courtois, Kissling, Brenken, Treumann, Marcusson, Schluter and "Sommer and Runge" company) are considered in the article. Many of these devices have not survived to our days and are undeservedly forgotten. [ABSTRACT FROM AUTHOR]

The terms heat and temperature are two distinct but closely related concepts. The core difference between heat and temperature is that heat deals with thermal energy, whereas temperature is more concerned with molecular kinetic energy. As a substance is cooled, it loses thermal energy. Eventually it will reach a temperature at which it no longer possesses any thermal or kinetic energy and so it can no longer be cooled; this temperature is absolute zero. Another unique temperature concept is the triple point of a substance; the temperature at which a substance exists simultaneously and in perfect equilibrium in a solid, liquid and gaseous phase. The triple point is unique for every substance; for water, it reaches its triple point at 0.01 °C at a pressure of 0.006 atmospheres. Temperature may be measured using the Celsius, Fahrenheit and Kelvin scales. Many clinical thermometers are designed to display the output in a digital format to enable easier monitoring as well as recording. Non-electrical thermometers are still in use today. Thermoregulation in the anaesthetized patient is achieved by the understanding of the mechanisms of heat loss, as well as the use of thermometers, warming and cooling devices. [ABSTRACT FROM AUTHOR]

Measuring reliably the correct temperature of a sooty flame in an internal combustion engine is important to optimise its efficiency; however, conventional contact thermometers, such as thermocouples, are not adequate in this context, due to drift, temperature limitation (≤2100 K) and slow response time (~10 ms). In this paper, we report on the progress towards the development of a novel ultra-high-speed combustion pyrometer, based on collection of thermal radiation via an optical fibre, traceably calibrated to the International Temperature Scale of 1990 (ITS-90) over the temperature range T = (1073-2873) K, with residuals <1%, and capable of measuring at a sampling rate of 250 kHz. [ABSTRACT FROM AUTHOR]

The goal of this work is to achieve the defect-free production of parts made using Additive Manufacturing (AM) processes. As a step towards this goal, the objective is to detect flaws in AM parts during the process by combining predictions from a physical model (simulation) with in-situ sensor signatures in a machine learning framework. We hypothesize that flaws in AM parts are detected with significantly higher statistical fidelity (F-score) when both in-situ sensor data and theoretical predictions are pooled together in a machine learning model, compared to an approach that is based exclusively on machine learning of sensor data (black-box model) or physics-based predictions (white-box model). We test the hypothesized efficacy of such a gray-box model or digital twin approach in the context of the laser powder bed fusion (LPBF) and directed energy deposition (DED) AM processes. For example, in the DED process, we first predicted the instantaneous spatiotemporal distribution of temperature in a thin-wall titanium alloy part using a computational heat transfer model based on graph theory. Subsequently, we combined the preceding physics-derived thermal trends with in-situ temperature measurements obtained from a pyrometer in a readily implemented supervised machine learning framework (support vector machine). We demonstrate that the integration of temperature predictions from an ab initio heat transfer model and in-situ sensor data is capable of detecting flaws in the DED-produced thin-wall part with F-score approaching 90%. By contrast, the F-score decreases to nearly 80% when either temperature measurements from the in-situ sensor or temperature distribution predictions from the theoretical model are used alone by themselves. This work thus demonstrates an early foray into the digital twin paradigm for real-time process monitoring in AM via seamless integration of physics-based modeling (simulation), in-situ sensing, and data analytics (machine learning). [ABSTRACT FROM AUTHOR]

The melt pool temperature is a key parameter in laser metal deposition (LMD) processes. Reliable temperature measurements are of obvious interest and essential for supervising and controlling the process. However, pyrometers tend to show a non-negligible directional dependency, due to the direction-dependent temperature distribution in the melt pool. We propose a model-based method for determining and physically compensating the misalignment of a pyrometer in an LMD process. The approach is based on a brief calibration run based on which the focus offset can be determined. The resulting offset is used to physically adjust the pyrometer. [ABSTRACT FROM AUTHOR]

The article concerns the analysis of selected and the most frequently used methods for temperature measurements in the aspect of their correct use in engineering applications related to industrial die forging processes. The research used the three most popular measuring devices, such as: monochromatic pyrometers with the simultaneous measurement of K-type thermocouple and thermal imaging camera. The research concerned mainly temperature measurements for forging tools divided into several stages in which individual tests were carried out, making detailed analyzes and indicating the most important measurement problems. Each subsequent research stage was in some way a consequence of the previous one. On this basis, the potential advantages and disadvantages of individual measurement methods were indicated and how one method can be verified by another one. It was indicated how and to what the best method or device should be used, so that the obtained result was correct and the person/engineer conducting such measurements was aware of the consequences of the conducted research and the problem of temperature measurements. [ABSTRACT FROM AUTHOR]

The problem of the precision of pyrometric measurements, associated with the convergence of readings of various pyrometers was examined. Readings in practice of pyrometric measurements of the overestimation of the measured temperature and a divergence of readings of various pyrometers are theoretically justified. One reason for the divergence of readings is the usage of an approximation calculation of the relationship for reduced emissivity in the equation of pyrometric measurement. The conditions for application of the specified equation are formulated. Calculation data of the effect of reduced emissivity on observed data are given, and practical recommendations for enhancing the precision of pyrometric measurements are made. [ABSTRACT FROM AUTHOR]

The methodology of determining the surface temperature of composite materials with unknown emissivity is studied. The methodology is implemented by using a standard sample of spectral normal emissivity over the range of wavelengths 1.65–1.80 μm and the industrially produced Metis M322 pyrometer functioning in the same range. The surface temperatures of the composite material under study and platinum, with significantly different values of spectral normal emissivity is determined by the temperature of the standard sample mounted on the materials under study, as measured by the pyrometer. The relative methodological error of determination of the surface temperature of materials under study did not exceed 1.7 and 0.5%, respectively, for the composite material and platinum for surface temperatures approximately 973 K. In the calculation of the error, the results of measuring the surface temperatures of the materials under study were used, obtained taking into account the temperature of the standard sample and in the absence of a standard sample. The imprecision of a priori data regarding emissivity of a standard sample in the interval (–0.01; 0.01) relative to the mean emissivity, equal to 0.19, increases the relative error of determination of the temperature of the composite material by 0.68%. Installation of a standard sample on the materials under study results in temperature modifications on the periphery of the surface, not exceeding 0.47 and 0.05%, respectively, for the composite material and platinum. [ABSTRACT FROM AUTHOR]

Selective laser melting (SLM) is an additive manufacturing (AM) technique for producing arbitrary work pieces, in which a laser beam is controlled to melt specific regions of a metal powder bed layer by layer so as to build up the required geometric form. In the present study, a method is proposed for calibrating the measurements obtained by a pyrometer for the melting pool temperature in the SLM of stainless steel 316L powder using the estimated values of the emissivity coefficients obtained from finite element heat transfer simulation and experimental tests. The accuracy in temperature prediction by heat transfer simulation is also confirmed by embedding a thermocouple into the powder bed. As a result, the calibration process is applicable to both one-color and two-color pyrometry methods. It is shown that the average error between the temperature measurements obtained from the calibrated pyrometer and the simulated temperature is just 1%. In other words, the feasibility of the proposed emissivity-based calibration method is confirmed. In the author's knowledge, this is the first proposed idea to calibrate the emissivity of the pyrometer based upon the simulation model for accurately extracting the true melting pool temperature. [ABSTRACT FROM AUTHOR]