Uncertainty Information, Links and a Local Directory Listing

Marc

Hunkered Down for the Duration
Staff member
Admin
#1
For those of you with uncertainty dancing in your dreams, here are some thread segments. If you read thru them, it's an education in uncertainty. These are culled from the listserve.

See Uncertainty Directory Listing

It's sorta a nice collection of thoughts. They don't have extensions and should load in your browser (depends upon your preferences) - and if you 'download' one (or more) file, you can open it (them) in your favourite text editor. Plain, vanilla ascii (.txt if you will) files.
 
Elsmar Forum Sponsor

Marc

Hunkered Down for the Duration
Staff member
Admin
#2
Date: Mon, 11 Oct 1999 10:24:16 -0700
From: "Dr. Howard Castrup"
To: 'Greg Gogates'
Subject: RE: Uncertainty book help

Amanda,

There are two basic procedures that I know of that are available on-line. One is found at our web site at http://www.isgmax.com - Link was: /unc_broc.htm and the other can be found at the Quametec site at http://www.quametec.com - Link was: /uncproc.htm

There is also commercially available software that may help you out. The packages that I hear mentioned most frequently are

1. GUM Workbench from the Danish Technological Institute http://www.gum.dk - Link was: /e-wb-home/gw_home.html

2. UncertaintyCalculator from Compaq http://www.callabmag.com - Link was: /Freeware.html

3. UncertaintyAnalyzer from ISG http://www.isgmax.com - Link was: /unc_broc.htm

Howard Castrup
President, Integrated Sciences Group
 

Marc

Hunkered Down for the Duration
Staff member
Admin
#3
Date: Sat, 9 Oct 1999 15:25:13 +0200
From: Sven Nytoft Rasmussen
Subject: SV: Uncertainty book help

Books on measurement uncertainty, here are two rather new ones, not included in the bibliography which Ralph Veale made available:

The book by Coleman and Steele is quite helpful. The authors do not adhere to the internationally agreed terms, however. Examples are mostly from thermodynamics, fluid flow etc. Hugh W. Coleman and W. Glenn Steele: "Experimentation and Uncertainty Analysis for Engineeers". 2nd. ed. John Wiley & Sons, 1999, ISBN 0-471-12146-0

The book by Adunka strictly follows the GUM method by ISO. It is, as far as I know, available in German only. Adunka's examples are mostly from metering in respect of legal metrology like e.g. heat meters for district heating, calibration of household gas meter etc. Franz Adunka: "Messunsicherheiten, Theorie und Praxis, 1st ed. Vulkan Verlag, 1998, ISBN 3-8027-2186-1.

Sincerely yours

Sven Nytoft Rasmussen, Ph.D.
Manager of center
Center for Metrology and Quality Assurance
Danish Technological Institute
P. O. Box 141
DK-2630 Taastrup, Denmark

Tlf. +45 43 50 44 40
Fax +45 43 50 72 73
Web: WWW.teknologisk.DK

You are welcome to check http://www.gum.dk for furhter information.
 

Marc

Hunkered Down for the Duration
Staff member
Admin
#4
Subject: Re: Calibration Issues for Small Firms /Scalies/Hellmann
Date: Wed, 3 Nov 1999 17:37:06 -0600
From: Moderator
From: JJH2000

Charley,

MEASUREMENT UNCERTAINTY is a rather obscure concept because it is precisely what we strive to and assume is eliminated whenever a measurement is taken of a unknown process variable. No one wants to hear that the temperature of water boiling in a pot is sorta 100 degrees Celcius, "give-or-take" 1 degree, or maybe 2 degrees, or 3 degress....and so on. There are many variables that would determine and effect the temperature measurement such as, the elevation above sea leavel, the ambient air pressure around the pot, the degree of accuracy of the temperature measuring device, its degree of precision giving the same indication every time given the same conditions, and so on. It's this "give-or-take" that is the uncertainty of the measurement. To make an anology, a proficient archer can consistently hit a smaller area of the larger target. But even Robin Hood didn't split his arrow with every other arrow shot. But he was good at hitting the bulls eye everytime, or so the legend goes. The bulls eye, itself, is not a point in space, but rather a very small area of the whole target.

To consistenly hit a 1 inch diameter circle at 30 yards, would be the standard for the proficient archer. If Robin utilized his archery skills in hunting, for example, the results would be consistent. The deer would fall every time, and venison would be turning on the spit back at camp every evening. We can quantify and define the MEASUREMENT UNCERTAINTY of Robin's skill by the documenting the size of the bulls eye.

Now the issue becomes how does one quantify and define MEASUREMENT UNCERTAINTY, to make it "known". That is something you must decide. What is the acceptable % error accuracy of your instrumentation? It is determined by the needs of the process being measured.

What is an acceptable percent of the total range for error? I maintain a 0.25% of total range for acceptable accuracy. In other words, the instrument I am calibrating must indicate the same value as the instruments of standard (certified by NIST) within 0.25% of the range being measured. For a 0 to 100 degree Celcius ranged instrument, it must be within 0.25 degrees of the reading of the standarized instrument, or else it fails. This standard has validity in the pharmaceutical, petrochemical and chemical process control environments where I work. But it might not be appropriate for you. Why, for example, should you spend hundreds, thousands, of dollars for a 0.25% accuracy temperature instrumentation device to cook your Thanksgiving turkey when a $3 thermometer from the drug store would be perfectly adequate?

The knowing of the MEASUREMENT UNCERTAINTY is the quantified and documented size of the bulls eye that works for you.

John
 
Thread starter Similar threads Forum Replies Date
B IEC 60601-2-10 - Accuracy of Pulse Parameters - Required Measurement Uncertainty IEC 60601 - Medical Electrical Equipment Safety Standards Series 3
F Missing value of Uncertainty B Measurement Uncertainty (MU) 8
F Issues in Uncertainty Estimation Measurement Uncertainty (MU) 5
F Operator Manual and Type B Uncertainty Measurement Uncertainty (MU) 3
F Learning Uncertainty Budget for Novice - Fluke 5520A Measurement Uncertainty (MU) 1
G Does pitch/increment/resolution of a ruled scale apply to measurement uncertainty as line item? Measurement Uncertainty (MU) 10
R Uncertainty in measurement larger than tolerance Measurement Uncertainty (MU) 2
S Uncertainty Budgets - Phase Noise (SSB), Harmonics Measurement Uncertainty (MU) 2
K ISO 17025:2017 clause 7.6.2 - Performing calibration of its own equipment shall evaluate the measurement uncertainty ISO 17025 related Discussions 6
M Informational US FDA Final Guidance – Consideration of Uncertainty in Making Benefit-Risk Determinations in Medical Device Premarket Approvals, De Novo Classificati Medical Device and FDA Regulations and Standards News 0
A Uncertainty Budget - Externally produced sensor module Measurement Uncertainty (MU) 1
E Discussion between co-worker on tolerance and uncertainty and how to apply it. Thoughts? 17025 ISO 17025 related Discussions 1
G Assigning a calibration tolerance - An x-y coordinate machine - Uncertainty as my verification tolerance General Measurement Device and Calibration Topics 4
G 3 Operator Std. Dev. and uncertainty calculation Measurement Uncertainty (MU) 2
G Reporting measurement uncertainty for custom items Measurement Uncertainty (MU) 2
L Gage R&R for test precision or uncertainty prediction? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 2
G Uncertainty of staging a short line scale standard on longer measuring machine? Measurement Uncertainty (MU) 4
K Measurement Uncertainty Budget (MU) of for Ultrasonic Thickness gauge Measurement Uncertainty (MU) 1
G NIST SOP 29 - Assignment of Uncertainty - Question General Measurement Device and Calibration Topics 0
M Medical Device News FDA news - 05-09-18 - Draft - Uncertainty in Benefit-Risk Determinations Other US Medical Device Regulations 0
G Can Measurement Machine Bias be part of Uncertainty? General Measurement Device and Calibration Topics 1
G How to include machine error in uncertainty calculations? Measurement Uncertainty (MU) 5
D Difference between uncertainty and expanded uncertainty of measurement General Measurement Device and Calibration Topics 1
M Calibration certificates avowing accuracy beyond the uncertainty limits? Measurement Uncertainty (MU) 7
G ANAB ISO 17025 Accreditation - Uncertainty and systematic error? ISO 17025 related Discussions 6
G How many Uncertainty Measurements for Micrometers and Calipers? Measurement Uncertainty (MU) 3
G What degrees of freedom means in uncertainty budget and how do I set the value Measurement Uncertainty (MU) 2
G Uncertainty Experts - ISO 17025 - If the Distribution is Rectangular Measurement Uncertainty (MU) 2
G Uncertainty Budget Examples for Caliper, Micrometer and Dial Gauge Measurement Uncertainty (MU) 3
P Uncertainty and Significantly Different Means - Buffer Solutions Measurement Uncertainty (MU) 4
S Pressure Gauge Calibration Uncertainty Calibration and Metrology Software and Hardware 5
E Uncertainty of Mean - Test rig that measures water temperatures Measurement Uncertainty (MU) 3
J Internal Laboratory Scope and Measurement Uncertainty (MU) IATF 16949 - Automotive Quality Systems Standard 1
G Manual Procedure with Uncertainty Budgeting for either a Caliper or Micrometer General Measurement Device and Calibration Topics 6
C MU (Measurement Uncertainty) in an Internal Calibration Laboratory Measurement Uncertainty (MU) 1
N How to Convert Micro Volts into Temperature Uncertainty Measurement Uncertainty (MU) 1
N Include homogeneity uncertainty into budget table for thermocouples Measurement Uncertainty (MU) 1
J CMM Uncertainty Calculation Question - Deviations Measurement Uncertainty (MU) 9
M Uncertainty Budget for a Micrometer Measurement Uncertainty (MU) 5
C Uncertainty Trainer in Texas? Measurement Uncertainty (MU) 3
P Purpose of calculating Uncertainty value in calibration study Measurement Uncertainty (MU) 5
C Uncertainty Estimation for Spark Optical Emission Device Measurement Uncertainty (MU) 1
W Dimensional Measurement of 10% accuracy and 25% uncertainty standard General Measurement Device and Calibration Topics 6
B Measurement Uncertainty using Minitab Measurement Uncertainty (MU) 2
J Uncertainty budget for IR thermometry at high T - 1000 - 1500?C Measurement Uncertainty (MU) 1
N Understanding the absolute uncertainty specification for a Fluke 5500A Measurement Uncertainty (MU) 3
M Help with uncertainty calculation in the calibration of a Pyrogen Test Processor Measurement Uncertainty (MU) 7
S How to track and manage all uncertainty budgets - Database? Measurement Uncertainty (MU) 3
I UUT Accuracy as part of Uncertainty Budget Measurement Uncertainty (MU) 6
A Uncertainty Measurement - What this accuracy specification "1% + 10^5": means? General Measurement Device and Calibration Topics 2

Similar threads

Top Bottom