National Physical Laboratory Video Presentations on Temperature Measurements

 

New references for high temperature measurements

As a culmination of an eight-year research programme an international collaboration has developed robust reference fixed points, studied their sensitivity to impurities and external conditions and finally measured their melting transition temperature.

This talk describes how 100+ measurements made by nine different NMIs have been combined to assign low-uncertainty thermodynamic temperatures to the melting transition of Re-C, Pt-C and Co-C metal-carbon eutectics.

At the simplest level, these fixed-points will provide new temperature references for the calibration of pyrometers at temperatures above the freezing point of silver (1234.93 K) and will thus reduce the uncertainties associated with high temperature measurement compared to those achievable using the International Temperature Scale of 1990 (ITS-90).

The thermodynamic temperatures of these fixed-points have been determined through direct measurement of the radiance of a blackbody cavity surrounded by the fixed-point material from Planck’s law and hence the Boltzmann Constant. The evolving mise en pratique for the definition of the kelvin encourages the realisation and dissemination of thermodynamic temperature.

This may be directly – and the work described in this talk shows that filter radiometry is sufficiently mature for this, or it may be by providing fixed-points with reference thermodynamic temperatures that have associated uncertainties – and this talk will outline such temperatures.
Innovations in High Temperature Measurement

A 49 minute review of the present technical status of High Temperature measurement by one of the leaders in temperature Metrology at NPL in the UK.

Presented by Dr. Graham Machin, NPL (Recorded July 2011)

Recent and unfolding innovations in this area promise step change improvements throughout the measurement chain; from realisation of temperature above 1300 K in National Measurement Institutes, dissemination of the scale to calibration laboratories, down to the practice of industrial high temperature thermometry.

Source: http://www.npl.co.uk/science-lectures/high-temperature-measurement

More details: Read more National Physical Laboratory Video Presentations on Temperature Measurements

New references for high temperature measurements

Summary of work reported for high temperature measurements from NPL

As a culmination of an eight-year research programme an international collaboration has developed robust reference fixed points, studied their sensitivity to impurities and external conditions and finally measured their melting transition temperature.

This talk describes how 100+ measurements made by nine different NMIs have been combined to assign low-uncertainty thermodynamic temperatures to the melting transition of Re-C, Pt-C and Co-C metal-carbon eutectics.

At the simplest level, these fixed-points will provide new temperature references for the calibration of pyrometers at temperatures above the freezing point of silver (1234.93 K) and will thus reduce the uncertainties associated with high temperature measurement compared to those achievable using the International Temperature Scale of 1990 (ITS-90).

The thermodynamic temperatures of these fixed-points have been determined through direct measurement of the radiance of a blackbody cavity surrounded by the fixed-point material from Planck’s law and hence the Boltzmann Constant.

The evolving mise en pratique for the definition of the kelvin encourages the realisation and dissemination of thermodynamic temperature.

This may be directly – and the work described in this talk shows that filter radiometry is sufficiently mature for this, or it may be by providing fixed-points with reference thermodynamic temperatures that have associated uncertainties – and this talk outlines such temperatures.

Recorded: 16 June 2015

Speaker: Emma Woolliams

Last Updated: 10 Sep 2015

Source: http://www.npl.co.uk/science-lectures/new-references-for-high-temperature-measurements

YouTube Video: https://www.youtube.com/watch?v=l4Ws6PiqQ9cs.YouTube video:

Further information

Related areas

Acoustic Gas Thermometry Review Article

Metrologia Cover Image
Metrologia Cover Image

Online  —  Acoustic gas thermometry (AGT) is not a very well known temperature measurement technique; several have been reported in the past.

This featured review article in Metrologia (Acoustic gas thermometry M R Moldover et al 2014 Metrologia 51 R1) by six authors from six different  NMIs around the world provides a modern update on the technology and its significance in helping determine values of physical reference temperatures points on the International Temperature Scale of 1990 (ITS-90).

Acoustic Gas Thermometry

Authors: M R Moldover1, R M Gavioso2, J B Mehl3, L Pitre4, M de Podesta5 and J T Zhang6

Review Article ABSTRACT

We review the principles, techniques and results from primary acoustic gas thermometry (AGT). Since the establishment of ITS-90, the International Temperature Scale of 1990, spherical and quasi-spherical cavity resonators have been used to realize primary AGT in the temperature range 7 K to 552 K. Throughout the sub-range 90 K < T < 384 K, at least two laboratories measured (T − T90). (Here T is the thermodynamic temperature and T90 is the temperature on ITS-90.) With a minor exception, the resulting values of (T − T90) are mutually consistent within 3 × 10−6 T. These consistent measurements were obtained using helium and argon as thermometric gases inside cavities that had radii ranging from 40 mm to 90 mm and that had walls made of copper or aluminium or stainless steel. The AGT values of (T − T90) fall on a smooth curve that is outside ±u(T90), the estimated uncertainty of T90. Thus, the AGT results imply that ITS-90 has errors that could be reduced in a future temperature scale. Recently developed techniques imply that low-uncertainty AGT can be realized at temperatures up to 1350 K or higher and also at temperatures in the liquid-helium range.

The complete article can be obtained online at: http://iopscience.iop.org/0026-1394/51/1/R1/article.

About Metrologia

It is the leading international journal in pure and applied metrology, published by IOP Publishing on behalf of Bureau International des Poids et Mesures (BIPM), the International Bureau of Weights and Measures. It is published by the Institute of Physics (IOP) in The United Kingdom.

Online at: http://iopscience.iop.org/0026-1394
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1 Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
2 Thermodynamics Division, Istituto Nazionale di Ricerca Metrologica, 10135 Turin, Italy
3 36 Zunuqua Trail, PO Box 307, Orcas, WA 98280-0307, USA
4 Laboratoire Commun de Métrologie LNE-Cnam (LCM), 61 rue du Landy, 93210 La Plaine Saint-Denis, France
5 National Physical Laboratory, Teddington, Middlesex, TW11 0LW, UK
6 National Institute of Metrology, Beijing 100013, People’s Republic of China

Temperature Calibration & Metrology Web Seminar Archives

Fluke Calibration’s Focus on Basics – RTDs – Digital & IR (Infrared Radiation) Thermometers

Calibration and Metrology Web Seminar Series

Online —  Fluke Calibration’s free online web seminars cover a wide range of calibration and temperature topics. More are scheduled monthly. To learn about upcoming events, check their web seminar page, or sign up for their e-news bulletins today.

If you have missed out on one of their live web seminar events, you can view the recordings in their web seminar archives. Here’s a list of current ones along with links to them (as of 1 August 2013). They are mostly in English, but several are also in Spanish.

Introduction to Temperature Measurement and Calibration

Techniques and Common Methods of Temperature Calibration

How Do You Know that Your Digital Thermometer is Accurate? »

How to Create a Temperature Measurement Uncertainty Budget »

Replacing Mercury Thermometers  Once and for All »

Kelvin and SI Units »

Redefinition of SI Units (Kelvin, Kilogram,  Ampere & Mole) »

How to Calibrate an RTD or Platinum Resistance Thermometer »

Cómo Calibrar un RTD »

How to Calibrate an RTD Using a Dryblock Calibrator »

Cómo Calibrar un RTD Usando un Calibrador de Bloque Seco »

Overcoming Drift: A Complete Guide to Maintaining Your PRTs »

Annealing an RTD: Why, When and How »

How to Maximize SPRT Measurement Performance »

Understanding Uncertainties Associated with Dryblock Calibrators »

How to Calibrate an IR Thermometer »

Como Calibrar Termómetros Infrarrojos »

Infrared Temperature Calibration 101 »

Advancements in Digital Thermometry Bridge Technology »

What is 0.06 PPM, Can Calibrate itself, and  costs much less that a bridge? »

Best Practices in Maintaining Temperature Calibration Equipment »

Making Laboratory Accreditation Work for You »

Temperature Measurement – Lecture 9

“The Science & Art of Temperature Measurement”

The first Lecture in Module 2, on the first topic of the Mechanical Measurements and Metrology, a part of the course from the Indian Institute of Technology Madras, India – online at youtu.be/GNOI_7ftbQ0.

It assumes an educational level of at least first year college engineering or higher, Some of the topics in this series of lectures also assume some knowledge of prior lectures in the Series (see below).

This is but one of the 50 videos in this course. A full list of the course contents is below.

The courses related to temperature measurement in this series are Numbers 9 through 19, inclusive, titles illustrated in red below. Additional lectures in this course detail related topics in measurement errors, and measurements of thermophysical properties of matter, subects that any serious student of temperature measurement should know well, indeed. The tiles of the latter lecture topics are shown as green in the list.

All of these lectures may be seen here or on YouTube.com, or on the NPTEL website at http://nptel.iitm.ac.in/video.php?subjectId=112106138, where flowplayer is used to display the lectures. Read more Temperature Measurement – Lecture 9

Calibrating Ordinary Thermometers

This six-minute video by AquaLab captures the correct way to check, verify and if necessary, adjust some ordinary thermometers using an ice bath.

Most people think that it’s easier to do so at the boiling point of water, but the ice point (very nearly 0.01 ° C at all normal atmospheric pressures) is far more stable than the boiling point that varies considerably with atmospheric pressure and consequently the altitude of the location at which the measurement is made.

What’s more, the ice point was, until about 1990, the fundamental reference point for the Centigrade and Fahrenheit scales. However, when the internationally agreed definition of the Celsius scale replaced the Centigrade scale, as a part of The International Temperature Scale (ITS-90) .

The new reference became the triple point of water precisely 0.01 ° C lower than the ice point. The ice point of water, a well-stirred mixture of ice and water is still as stable as ever, for ice and water that are free of contaminants (that is, both made up of distilled, de-ionized water). Read more Calibrating Ordinary Thermometers

Temperature (T)-Bob Abel on YouTube

Dr. Bob Abel of Olympic College in Bremerton, Washington (USA) has a series of YouTube videos that we think are very well done. His low-key and sometimes humorous approach to the basics of science and temperature, as concepts, and how some temperature sensors work, are some of the cleverest and most viewer-friendly ones we’ve seen to date.

Below are his two brief presentations on temperature and scale/unit conversions in lumps of about 5 to 7 minutes each. There are many more at www.youtube.com/olympiccollege.

First:

Read more Temperature (T)-Bob Abel on YouTube