316. Temperature control in the H.T.S.T. pasteurization process

1945 ◽  
Vol 14 (1-2) ◽  
pp. 1-20 ◽  
Author(s):  
J. A. Hall
Keyword(s):  
Temperature Measurement ◽  
Temperature Control ◽  
Vapour Pressure ◽  
Research Programme ◽  
National Physical Laboratory ◽  
Experimental Results ◽  
The Other ◽  
Measuring Instruments ◽  
Speed Of Response ◽  
Physical Laboratory

An investigation has been made into the accuracy and speed of response of temperature-measuring instruments suitable for use in the control of H.T.S.T. pasteurization. Thermocouples used in conjunction with a ‘d.c. amplifier’ recorder system are shown to be markedly superior to both vapour-pressure and mercury-in-steel thermometers. The accuracy of temperature measurement is about ±0.3°F. as against ±1°., while the lag constant is about 0.2 sec. as against about 3 sec. Response to small, rapid and transient changes of temperature is also shown to be greatly improved. The operation of control contacts by the thermocouple recorder was found to be reliable to well within the limit of accuracy of calibration, but the other types showed variations of the order of ±1°F., in addition to the uncertainties of calibration.The work described in this paper was undertaken at the request of the National Institute for Research in Dairying as part of the research programme of the National Physical Laboratory, and is published by permission of the Director of the Laboratory. The author wishes to acknowledge the help he has received from Dr A. T. R. Mattick and Miss E. R. Hiscox of the National Institute for Research in Dairying and from his colleagues Mr C. Wigley and Miss V. M. Leaver. Dr Mattick and Miss Hiscox supplied the experimental results given in the introduction, for the drafting of which they are largely responsible. Mr Wigley derived the equations used in computing the theoretical curves of Text-fig. 6 and Miss Leaver assisted with the observational work.

HiTeMS: A Pan-European Project to Solve High Temperature Measurement Problems in Industry

2012 ◽  
Vol 45 (10) ◽  
pp. 315-318 ◽  
Author(s):  
Graham Machin
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Temperature Scale ◽  
Research Programme ◽  
National Physical Laboratory ◽  
The European Union ◽  
Physical Laboratory ◽  
High Temperature Measurement ◽  
Metrology Research ◽  
High Temperature Fixed Points

In my previous article [1] I discussed some of the innovations that are taking place at the National Physical Laboratory (NPL) in improving high temperature measurement. Starting with the current defined temperature scale ITS-90 [2, 3], I introduced the concepts of high-temperature fixed points [4], new types of thermocouple for use to 1500°C [5, 6] and developments in self-validation for contact thermometry sensors [7] and showed that high temperature measurement is undergoing a quiet revolution throughout the measurement chain. Here I want to set the work at NPL in a broader context of developments in the European Union (EU), again led from NPL, through the European Metrology Research Programme project “HiTeMS: High Temperature Measurement Solutions for Industry”.

Development of a High Temperature Interconnect Solution as an Alternative to High Lead or Gold Content Solders

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000196-000206
Author(s):  
Martin Wickham ◽  
Kate Clayton ◽  
Ana Robador ◽  
Chris Hunt ◽  
Robin Pittson ◽  
...  
Keyword(s):  
High Temperature ◽  
Electronic Materials ◽  
Research Programme ◽  
National Physical Laboratory ◽  
Electrical Performance ◽  
Processing Temperature ◽  
Gold Content ◽  
Physical Laboratory ◽  
Electronic Assemblies ◽  
High Lead

AbstractA collaborative research programme between project partners Microsemi, the National Physical Laboratory (NPL) and Gwent Electronic Materials (GEM), has successfully developed innovative materials specifically designed to offer an alternative for high Pb or Au content materials to increase the operating temperature of electronic assemblies. Currently, for electronic assemblies to operate at high temperature, they must use a high lead solder or a very expensive gold based solder to withstand these temperatures. The ELCOSINT project has developed an inexpensive lead-free alternative for joining high temperature electronics suitable for operating at temperatures above 250°C utilising standard surface mount assembly processes. This paper summarises the work undertaken by the authors to develop and better understand this new family of electrical interconnection materials. The project brought together a materials supplier (GEM – Gwent Electronic Materials), an end-user (MSL - Microsemi) and an technology research organisation (NPL – National Physical Laboratory) to jointly develop, test and implement in production, the solution based on silver-loaded silicone materials. This paper focuses on the testing and materials evaluation undertaken at NPL to determine the long term performance of these alternative materials including high temperature ageing up to 300°C, thermal cycling and damp heat testing. Details of the shear strength and electrical performance of interconnects between the substrates and components during the test regimes are given. The manufacturing process is outlined including details of the test vehicles utilised. The processing temperature for the conductive adhesive is 250°C which offers additional advantages in potential improvements in component and substrate reliability compared to soldered solutions which would typically be processed at temperatures above 300°C.

“ Ten Years' Testing of Model Seaplanes ”

1923 ◽  
Vol 27 (149) ◽  
pp. 224-243
Author(s):  
G. S. Baker
Keyword(s):  
Experimental Work ◽  
Royal Society ◽  
General Meeting ◽  
National Physical Laboratory ◽  
The Other ◽  
Experimental Tank ◽  
Know How ◽  
Other Hand ◽  
Physical Laboratory ◽  
Hull Design

An Ordinary General Meeting- of the Society was held at the Royal Society of Arts, on Thursday, February ist, 1923, Professor L. Bairstow in the chair.The Chairman, in opening- the proceedings, said that Mr. G. S. Baker, O.B.E., of the National Physical Laboratory, would deal with flying boats and seaplanes. He would deal with the hull and its design, that part of the seaplane which differentiates it from the aeroplane. That subject had been touched on very lightly by Major Rennie at the previous meeting of the Society, in view of the present paper by Mr. Baker.Mr. Baker had begun work in 1912 on the problems of hull design, at a time when nothing of a definite nature was known; a few individual experiments had been carried out, but there was no systematised knowledge at all at that time. From that state of ignorance a great deal of experimental work had now rescued us. He did not know how far Mr. Baker would stress the point, but it was quite clear, from the investigation of certain accidents to seacraft, that there were fundamental differences in the behaviour of seaplane hulls on the water, differences which had a great deal of effect on the risk of flying-. For instance, if one type of hull was such that when the plane rose in the air it stalled, then all the aerodynamical consequences of stalling- followed, and there was difficulty. On the other hand, it appeared that we had a type of flying- boat which did not make the plane stall on getting into the air, and consequently if it came back to the water it was still controlled. For this type of development, which he believed really dated back to the C.E.i, we were mainly indebted to Mr. Baker and his associates at the National Physical Laboratory, and to the generosity of Sir Alfred Yarrow in placing such a magnificent piece of apparatus as the experimental tank at the disposal of the nation.Mr. Baker then read his paper on “ Ten Years’ Testing of Model Seaplanes.”

The Horizontal Wind Tunnel at East London College

1914 ◽  
Vol 18 (71) ◽  
pp. 302-307
Author(s):  
A. P. Thurston ◽  
N. Tonnstein
Keyword(s):  
Wind Tunnel ◽  
National Physical Laboratory ◽  
The Other ◽  
Horizontal Wind ◽  
Bell Mouth ◽  
Physical Laboratory

The horizontal wind tunnel at East London College consists of a wooden tube, .2 feet square in section by lift. 6in. long, through which air may be drawn at velocities up to 50 m.p.h. by means of a 6½ h.p. motor. It was designed and constructed by Messrs. Cedric Lee and G. Tilghman Richards from sketches supplied by one of the authors and was modified later by the addition of a wind disperser as the result of information kindly supplied by Dr. Stanton, of the National Physical Laboratory. This disperser was added principally with the object of reducing the draught in the room and of preventing pulsations of the air current. The tunnel is provided with a bell mouth to ease the air into it, and at the other end it is connected to the disperser by a metal duct, 3ft. 6in. long, expanding from 2ft. square to 3ft. 6in. diameter. The propeller is mounted in the enlarged end, which is cylindrical for some 7 inches, so as to draw the air through the tunnel.

scholarly journals National Physical Laboratory Radiocarbon Measurements II

Radiocarbon ◽  
1964 ◽  
Vol 6 ◽  
pp. 25-30 ◽  
Author(s):  
W. J. Callow ◽  
M. J. Baker ◽  
Daphne H. Pritchard
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Half Life ◽  
Research Programme ◽  
National Physical Laboratory ◽  
Reference Standard ◽  
Best Value ◽  
Physical Laboratory ◽  
The Difference ◽  
Absolute Age

The following list comprises measurements made since those reported in NPL I and is complete to the end of November 1963.Ages are relative to a.d. 1950 and are calculated using a half-life of 5568 yr. The measurements have been corrected for fractionation and referred to 0.950 times the activity of the NBS oxalic acid as a contemporary reference standard. The quoted uncertainty is one standard deviation derived from a proper combination of the parameter variances, viz. those of the standard and background measurements over a rolling twenty-week period, of the sample measurements from at least three independent fillings, of the δC13 measurements and of the de Vries effect (assumed to add an additional uncertainty equivalent to a standard deviation of 80 yr). Any uncertainty in the half-life has been excluded so that relative C14 ages may be correctly compared. Absolute age assessments, however, should be made using the accepted best value for the half-life and the appropriate uncertainty included. If the net sample activity is less than 4 times the standard error of the difference between the sample and background activities, a lower limit to the age is reported equivalent to a sample activity of 4 times the standard error of this difference.The description of each sample is based on information provided by the person submitting the sample to the Laboratory.The work reported forms part of the research programme of the Laboratory and is published by permission of the Director.

Design of Supercritical Aerofoils

1974 ◽  
Vol 25 (4) ◽  
pp. 245-265 ◽  
Author(s):  
R C Lock ◽  
J L Fulker
Keyword(s):  
Final Section ◽  
Theoretical Calculations ◽  
Lift Coefficient ◽  
Weak Shock ◽  
National Physical Laboratory ◽  
Experimental Results ◽  
Viscous Effects ◽  
Physical Laboratory ◽  
The Finite Difference Method ◽  
Low Speeds

SummaryA survey is given of experimental results on a series of aerofoils designed in recent years, first at the National Physical Laboratory and later at the Royal Aircraft Establishment, with the intention of operating at relatively high subsonic Mach numbers (around 0.8) with, on the upper surface, a large extent of supercritical flow, terminated by a weak shock wave. The paper describes the design of a basic aerofoil, together with some modifications to it which were successful in improving its performance at both high and low speeds. It is shown that the best of these aerofoils, with thickness/chord ratio 0.105, has a drag rise Mach number of 0.80 at a lift coefficient of 0.5, thus comparing favourably in this respect with other published examples; its maximum lift coefficient at low speeds, 1.2, is also satisfactory for an aerofoil of this thickness. In a final section some comparisons are given between these experimental results and some theoretical calculations by the finite-difference method of Garabedian and Korn, including a partial allowance for viscous effects. It is concluded that, although reasonable overall agreement with experiment is often obtained, further improvements in this theory are needed before it can be used with confidence for practical purposes.

The Research of Use Database to Build Data String in Robots

2013 ◽  
Vol 418 ◽  
pp. 34-37
Author(s):  
Yann Liang Li ◽  
Chang Chun Kao
Keyword(s):  
Service Property ◽  
Experimental Results ◽  
The Other ◽  
It Industry ◽  
Processing Mode ◽  
Database Model ◽  
Input And Output ◽  
Speed Of Response ◽  
The Future ◽  
Speed And Accuracy

The convenient living is created by IT industry, on the other hand industries are from human production transform robotics automation. In the future, robots not only possess manufacturing functions but also have service property. However, if the interaction that robots with service property just only be entered with a single, it has limited functionality. The purpose of this study is investigating the conception of database into robots, load data from database and save processed data into database, it will lessen wrongs and improve speed of response. In this study, will be compared two programs, one is the input and output processing by program, the order one is add database with function of save and load. Result of the comparison apply to processing mode of robot. The experimental results show that use database model can upgrade speed and accuracy that stream transmit, it will provide more convenient automated service contribution.

Wind Tunnels

1927 ◽  
Vol 31 (200) ◽  
pp. 799-806 ◽  
Author(s):  
W. Widgery
Keyword(s):  
National Physical Laboratory ◽  
Present Form ◽  
The Other ◽  
Wind Tunnels ◽  
Circular Path ◽  
Flow Past ◽  
Other Hand ◽  
Physical Laboratory ◽  
A Current

The wind channel and the whirling arm have been devised and perfected over a period of a number of years with a view to providing reliable aerodynamic data for aircraft designers. Of late years the wind channel has been used considerably more than the whirling arm.In the two pieces of apparatus distinct methods are used. In the whirling arm the model is carried through the air, which is stationary, in a circular path by a long arm. In the wind channel, on the other hand, the model is stationary and a current of air is caused to flow past it.Various types of wind channel have been evolved, but I intend to describe fully the English wind channel in its present form, as perfected by the National Physical Laboratory and the Royal Aircraft Establishment, Farnborough.

scholarly journals X. The aerodynamics of a spinning shell

1921 ◽  
Vol 221 (582-593) ◽  
pp. 295-387 ◽  
Keyword(s):  
National Physical Laboratory ◽  
The Other ◽  
Scientific Interest ◽  
Physical Laboratory ◽  
Heavy Work ◽  
General Scientific ◽  
Made In

This paper contains the results, theoretical and experimental, of work undertaken, at the request of the Ordnance Committee, by the authors as Technical Officers of the Munitions Inventions Department. Permission to publish such parts as appear to be of general scientific interest has now been granted by the Ordnance Committee and the Director of Artillery. The publication of this paper has received their sanction. The experiments in question were carried out at the firing ground of H. M. S. “Excellent,” Portsmouth; the Experimental Department, H. M. S. “Excellent,” also provided the 3-inch guns used and the material for the construction of the range. The authors’ best thanks are due to the officers of this department, especially Lieut.-Commander R. F. P. Maton, O. B. E., R. N., without whose cordial co-operation these experiments could never have been carried out; also to the other officers of the Munitions Inventions Department who assisted in the heavy work of making and analysing the observations. The aeronautical measurements at low velocities, required for comparison, were made in the wind channels of the National Physical Laboratory, by arrangement with the Director and the Superintendent of the Aero­nautical Department, to whom also we wish to express our thanks.

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