Theory and methods of optical pyrometry

Kostkowski, Henry J.; Lee, R. D.

doi:10.6028/nbs.mono.41

Cited by 45 publications

(14 citation statements)

References 11 publications

(34 reference statements)

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“…A definite indication of the relative quality of the blackbody and associated te mpe rature uniformity was obtained in a manner pointed out by Kostkowski and Lee [20]. With reference to figure 4 it is evident that the upper portion of the outer crucible (susceptor) represents another blackbody having an effective emittance for tungsten calculated to be 0.960 at room temperature and 0.958 at 2700 0c.…”

Section: T = True Temperature (O K)mentioning

confidence: 76%

Effect of environment upon the melting point of Al2O3

Schneider

McDaniel

1967

J. RES. NATL. BUR. STAN. SECT. A.

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The me ltin g point of AI, O" has bee n d e termined in vac uum . a ir. a rgon. a nd he lium utilizin)': iridium or tun ),:s te n co ntain ers. A ll me ltin g po int expe rim e nt s we re conduc ted in indu c ti on furna ces capab le of hea ti ng s ma ll sa mpl es und er b lackbody co ndition s to 3000 °C in vacuum. 2600 °C in inert at mosp he res. a nd 2400 °C in air. Temperatures we re co ntinu ous ly mo nit o red wit h a reco rding phutoe lec tri c pyrome ter whi c h has a se n sitivity of±0.2° at 1063 °C and ± 10 at 2000 0c. Meltin g points were determ in ed on s pec im ens having a purity in excess of 99.9 pe rce nt. T he data indi c at e d that th e me ltin g poin t of AI ,O" d e te rmin ed in vac uum (-6.5 X 10 -5 torr) is 2051 °C OPTS). T he overa ll maximum un ce rt a int y was es tim ate d to be ± 6 0c. Th e mea s ure me nt s th e m se lves we re prec ise within ± 1.5 0c. Vacuum trea tm e nt had leas t de t rimenta l e ffec t upon th e AI,03 spec im e ns. Eac h of the gaseous a tmo s ph e res in c lu ding air yie lded lower me lti ng point s for AI,O", p res umably d ue to a premeltin g p he nom e no n.Key Word s : A I,O". di ss ocia tion. e nvironm e nt a l e ffec ts . me ltin g po int. prc mc ltin g:.

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Section: T = True Temperature (O K)mentioning

confidence: 76%

Effect of environment upon the melting point of Al2O3

Schneider

McDaniel

1967

J. RES. NATL. BUR. STAN. SECT. A.

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“…The emissivity of tungsten selected [17] was 0.425 for this filament. The procedure must be repeated frequently, as the lamp reference is operated far above its long term stability point [18]. and color ratio between these two measurements has a precision of better than ± 20 K, indicating accuracy attained of^0.6 percent.…”

Section: Methodsmentioning

confidence: 99%

NBS :

Manning¹

1981

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The work emphasizes measurement of materials properties and thermophysical properties important in materials processing applications.It has two main thrusts : 1)Carrying out precision measurements in space and investigating the feasibility of improved measurements when the space environment offers a unique opportunity for performing such measurements. These measurements would be useful for either space processing or processes on the ground. 2)Obtaining precision measurements on materials properties when these properties are important to the design and interpretation of space processing experiments. These measurements would be carried out either in space or on the ground.This work has been carried out in five tasks. These tasks have, as two of their focal points, the role of convection effects and the role of container effects, both of which would differ in space-based experiments from those found in ground-based experiments.The results obtained for each task are given in detailed summaries in the body of the report.Briefly, in Task The oxygen was undoubtedly in the form of a gallium oxide and could be effectively reduced and removed by heating; the carbon, however, remained in the form of small platelets floating on the surface. In an attempt to clean a spot on the surface to obtain the spectrum of clean gallium, we sputtered a small area with argon ions using a conventional low power gun. The ion bombardment was found to generate large scale fluid flow that eventually carried all of the carbon into the ion beam where it was sputtered away. The result was a gallium surface which appeared to be perfectly clean within the measurement limits of the Auger spectrometer.Our first surface tension measurements on gallium sessile drops with surfaces cleaned by sputtering will be seen to have a different temperature dependence 9 from our previous results with thermally cleaned surfaces. This observation reinforces our feeling that the sputter cleaning process will be an important tool in future studies of liquid surfaces. We will present here our current ideas on the mechanism responsible for the fluid flow during the sputtering process .The study of surface segregation in liquid alloys is an area which seems particularly suited to A.E.S. Prior to forming a sessile drop, the bell jar was evacuated and the hot stage temperature was raised to 500°C for about an hour. After cooling, the system was back filled with dry nitrogen gas. A small port was removed and gas allowed to flow through the system while the cup was partially filled with liquid gallium using a syringe. The port was then replaced and the system very slowly evacuated with the sorption pumps. If evacuation is too rapid the expansion of gases trapped under the gallium in the cup will expel the liquid charge. After evacuation the process is repeated to form a sessile drop large enough for surface tension measurements. The Gallium SurfaceAs we have previously reported, (1) the surface of a newly formed sessile drop of gallium is covered by a thin solid oxide lay...

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“…June 2007 1 Introduction For temperature measurements, many sensors are also available, from the classical thermocouples up to more sophisticated non-contact sensors like infrared cameras or pyrometers [14,15]. Thus, getting the strains and temperature at the same time implies generally a multi-instrumentation of the set-up and it is not so easy to combine the measurements of various categories in order to get the strains and the temperature at a given point of the specimen surface.…”

Section: Preprint Submitted To Experimental Mechanicsmentioning

confidence: 99%

An Innovative Method for 3-D Shape, Strain and Temperature Full-Field Measurement Using a Single Type of Camera: Principle and Preliminary Results

et al. 2007

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An innovative technique for measuring both the shape, the displacement, the strain and the temperature fields at the surface of an object using a single stereovision sensor is proposed. The sensor is based on two off-the-shelf low-cost high-resolution uncooled CCD cameras. To allow both dimensional and thermal measurements, the sensor operates in the visible and near infrared (NIR) spectral band (0.7-1.1 µm), and a radiometric and geometric calibration of the sensor is required. This technique leads to a low-cost camera-based simplified instrumentation that gives simultaneously dimensional/kinematical and thermal field measurements.Key words: geometric camera calibration, radiometric camera calibration, shape measurements, strain measurements, temperature measurements, full-field measurements, stereovision, digital image correlation (DIC), stereo-correlation, 3-D metrology, experimental mechanics. Preprint submitted to Experimental MechanicsJune 2007 1 Introduction For temperature measurements, many sensors are also available, from the classical thermocouples up to more sophisticated non-contact sensors like infrared cameras or pyrometers [14,15]. Thus, getting the strains and temperature at the same time implies generally a multi-instrumentation of the set-up and it is not so easy to combine the measurements of various categories in order to get the strains and the temperature at a given point of the specimen surface. 2 classical thermocamera with the 3-D shape data provided by a stereovision sensor. Their technique requires three cameras (an IR camera and two CCD cameras for the stereovision sensor) and a specific calibration procedure is needed to perform the fusion of the thermal and kinematical data provided by two different types of cameras. Satzger et al. [17] propose to utilize an infrared camera with a fringe projection technique to obtain a cloud of 3-D points and

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Theory and methods of optical pyrometry

Cited by 45 publications

References 11 publications

Effect of environment upon the melting point of Al2O3

Effect of environment upon the melting point of Al2O3

NBS :

An Innovative Method for 3-D Shape, Strain and Temperature Full-Field Measurement Using a Single Type of Camera: Principle and Preliminary Results

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