The Cove Business Standards Discussion Forums More Free Files Forum Discussion Thread Post Attachments Listing Cove Discussion Forums Main Page
Uncertainty and Significantly Different Means - Buffer Solutions
UL - Underwriters Laboratories - Health Sciences
Uncertainty and Significantly Different Means - Buffer Solutions
Uncertainty and Significantly Different Means - Buffer Solutions
Uncertainty and Significantly Different Means - Buffer Solutions
Uncertainty and Significantly Different Means - Buffer Solutions
Uncertainty and Significantly Different Means - Buffer Solutions
Uncertainty and Significantly Different Means - Buffer Solutions
Uncertainty and Significantly Different Means - Buffer Solutions
Uncertainty and Significantly Different Means - Buffer Solutions
Uncertainty and Significantly Different Means - Buffer Solutions
Go Back   The Elsmar Cove Business Systems and Standards Discussion Forums > > >
Forum Username

Elsmar Cove Forum Visitor Notice(s)

Wooden Line

Uncertainty and Significantly Different Means - Buffer Solutions


Elsmar XML RSS Feed
Elsmar Cove Forum RSS Feed

Monitor the Elsmar Forum
Sponsor Links




Courtesy Quick Links


Links Elsmar Cove visitors will find useful in the quest for knowledge and support:

Jennifer Kirley's
Conway Business Services


Howard's
International Quality Services


Marcelo Antunes'
SQR Consulting, and
Medical Devices Expert Forum


Bob Doering
Bob Doering's Blogs and,
Correct SPC - Precision Machining


Ajit Basrur
Claritas Consulting, LLC



International Standards Bodies - World Wide Standards Bodies

ASQ - American Society for Quality

International Organization for Standardization - ISO Standards and Information

NIST's Engineering Statistics Handbook

IRCA - International Register of Certified Auditors

SAE - Society of Automotive Engineers

Quality Digest

IEST - Institute of Environmental Sciences and Technology


Some Related Topic Tags
buffer solutions, measurement uncertainty (mu), uncertainty budget (measurement)
Reply
 
Thread Tools Search this Thread Rate Thread Content Display Modes
  Post Number #1  
Old 27th September 2017, 11:03 AM
PETERROW

 
 
Total Posts: 7
Question Uncertainty and Significantly Different Means - Buffer Solutions

Hi there

I have discovered an "interesting" (meaning I do not know how to proceed) problem.

I am estimating an uncertainty budget for a measurement of buffer solutions. We measure the buffer solutions with two pH electrodes in the same solution at the same time. Temperature is controlled (25C +/- 0.2). The electrodes are calibrated using primary standard buffer solutions with pH values either side of the solution being measured. Around 300 measurements are collected over 15 minutes after which the mean of the measurements of each electrode are combined to deliver the total mean, which is attributed to the pH of the buffer.

Now my problem. The method that I have just stated, I believe, is valid IF there is no significant difference between the measurements from the individual electrodes. Unfortunately, there is a significant difference.

In practical terms, the differences are small (i.e. less than the uncertainty of the primary standard buffer) but never the less statistically significant.

My question is can I use distribution of the difference between the buffers to calculate the measurement uncertainty of the electrodes or because of the statistical significance, must I go back to the drawing board and re-examine my measurement method.

Any ideas are much appreciated.

Sponsored Links
  Post Number #2  
Old 11th October 2017, 09:39 PM
Hershal's Avatar
Hershal

 
 
Total Posts: 2,498
Re: Uncertainty and Significantly Different Means - Buffer Solutions

Have you tried Guardbanding to address this?
Sponsored Links

  Post Number #3  
Old 12th October 2017, 12:37 AM
PETERROW

 
 
Total Posts: 7
Re: Uncertainty and Significantly Different Means - Buffer Solutions

Guardbanding? You will have to help me more here, I have never heard of guardbanding. Could you post a link please?
  Post Number #4  
Old 12th October 2017, 03:11 PM
Hershal's Avatar
Hershal

 
 
Total Posts: 2,498
Re: Uncertainty and Significantly Different Means - Buffer Solutions

The most current version of the GUM has it I believe. The current edition of The Metrology Handbook should also have some information. The following link may also help. I make no claim regarding the website, but it appeared to have a good explanation.

Guard-banding | Applications of statistics in Measurement & Testing
Thanks to Hershal for your informative Post and/or Attachment!
  Post Number #5  
Old 12th October 2017, 05:02 PM
Marc's Avatar
Marc

 
 
Total Posts: 26,030
Re: Uncertainty and Significantly Different Means - Buffer Solutions

Thank you for your help, Hershal!
Reply

Lower Navigation Bar
Go Back   The Elsmar Cove Business Systems and Standards Discussion Forums > > >

Bookmarks



Visitors Currently Viewing this Thread: 1 (0 Registered Visitors (Members) and 1 Unregistered Guest Visitors)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Forum Search
Display Modes Rate Thread Content
Rate Thread Content:

Forum Posting Settings
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Emoticons are On
[IMG] code is On
HTML code is Off


Similar Discussion Threads
Discussion Thread Title Thread Starter Forum Replies Last Post or Poll Vote
Re-Use of Diagnostic Reagent Solution Labels - Buffer Solutions for Internal Use rwp_kennedy ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 1 30th August 2017 08:51 AM
What is MSU buffer solution? salah 20012 Manufacturing and Related Processes 1 31st May 2015 10:44 AM
Uncertainty Measurement - What this accuracy specification "1% + 10^5": means? akmal122g General Measurement Device and Calibration Topics 2 14th January 2015 07:14 PM
pH Buffer and Conductivity Standard Solutions - No Calibration Report Dongzkie IATF 16949 - Automotive Quality Systems Standard 8 10th December 2011 10:08 AM
Calibration Results Significantly Out & Product Impact Satellite General Measurement Device and Calibration Topics 1 6th June 2006 07:51 PM



The time now is 11:41 PM. All times are GMT -4.
Your time zone can be changed in your UserCP --> Options.


 
 
 


NOTE: This forum uses "Cookies"