SBS - The Best Value in QMS software

Determining Uncertainty from Gage R&R

R

RichardJDrexler

Registered
#1
#1
Folks,

Let me preface this with the fact that I am not six sigma certified.

Process:
1. Weigh tin (Pre-weight)
2. Add solvent w/ contaminate to tin
3. Evaporate solvent; leaving contaminate in tin
4. Weigh tin again (Post-weight)
5. Delta of weights is weight of contaminate

I am trying to determine the uncertainty of a measurement taken with a balance. Given the nature of the work it is extremely important to over estimate the weight of the contaminate rather than under estimate it.

Results from Gage R&R:
Equipment Variation: 0.00003g
Appraiser Variation: 0.00001g
Interaction Variation: 0.00001g

Given my variation results, is it safe to call the sum of my variations the "error" of a possible measurement?

Right now the assumption is that the balance is accurate down to 0.00001g since that is the resolution displayed on the screen. So if the pre-weight measured 2.00000g and the post-weight measured 2.00001g we would say there is 0.00001g of contaminate. I don't think this is accurate given how much a reading on the balance fluctuates after it decides the reading is acceptable.

My thought is that we need an error around the measurement to be conservative. So if the pre-weight measured 2.00000 +/- 0.00005g and the post-weight measured 2.00001g +/- 0.00005g then the amount of contaminate I could have in the worst case is actually: 2.00006g - 1.99995g = 0.00011g. Therefore to be conservative I should use 0.0011g as my result. Additionally, this means I would never be able to claim that I have a contaminate with a weight less than 0.00010g.

I have attached the spreadsheet with my work.

Cheers.
Rich
 

Attachments

Quickly Organize an Intelligent TDP from DISCUS
Elsmar Forum Sponsor
Jen Kirley

Jen Kirley

Quality and Auditing Expert
Staff member
Admin
#2
#2
Good day Rich, I am sorry for the delay in this response.

There is a great deal of information about GR&R and uncertainty out there, ranging from NIST to Universities to bloggers. I am not affiliated with ISO Budgets. I selected this page because it made the most sense to me.

Another Elsmar thread (see a list of related threads at the bottom of this page) describes GR&R as an incomplete tool for measurement uncertainty because of the uncertainty in calibration.

I hope other Covers will also comment. Statistics is not my strongest skill.
 
You must log in or register to reply here.
Thread starter Similar threads Forum Replies Date
howste Determining Calibration Uncertainty with Unknown Reference Standard Uncertainty Measurement Uncertainty (MU) 8
K Determining Uncertainty Components in Volumes delivered with a Pipettor Measurement Uncertainty (MU) 3
O Determining Uncertainty Measurement of Co-ordinate Measuring Machine (CMM) Measurement Uncertainty (MU) 6
S Determining a device category according to the MDR EU Medical Device Regulations 3
S Determining the requirements for the products and services ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 3
Q Determining Adverse Effects of Corrective/Preventive Actions ISO 13485:2016 - Medical Device Quality Management Systems 2
S Determining sample sizes for PQ Qualification and Validation (including 21 CFR Part 11) 4
M Determining if an Insulin Pen Testing Machine is a Medical Device? EU Medical Device Regulations 4
M Determining a tolerance value for Measuring devices in-house inspection General Measurement Device and Calibration Topics 12
D Determining the the maximum number of reprocessing cycles of attachments CE Marking (Conformité Européene) / CB Scheme 2
A IATF 16949 4.3.1 - Determining the scope of the quality management system - supplemental IATF 16949 - Automotive Quality Systems Standard 9
D ISO 9001:2015 4.3 Determining the Scope of the QMS ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 3
J Determining SPC tolerance Statistical Analysis Tools, Techniques and SPC 21
B Determining SAT Offsets vs TUS Offsets per SAE AMS 2750E AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 0
B Determining sample size for device sterility Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
D Determining of sample size for 'Operational Qualification' AQL - Acceptable Quality Level 5
R Question on determining defective units - I am not recording fixture to part rejected Statistical Analysis Tools, Techniques and SPC 5
S Clause 8.2.2 Determining the requirements for products and services ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 5
D Determining Calibration Frequency schedule for items used in production Manufacturing and Related Processes 2
C Determining if Maintenance Contractor is an External Service subject to ISO 9001 Clause 8.4 ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 43
S AS9100D PEAR - Examples for organization's method for determining process results? AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 5
I Determining Calibration Tolerance of a Measurement Device General Measurement Device and Calibration Topics 2
J ISO 17025 Documented Procedure for 6.2.5 - Determining competency ISO 17025 related Discussions 4
V Determining FDA 820 (registration) vs ISO 13485 - Supplier gives us the kit ISO 13485:2016 - Medical Device Quality Management Systems 1
J ISO 9001 8.4.1 - Determining controls applied to externally provided processes ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 8
E Determining what is good and what is bad can be subjective - when is it a quality issue? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 9
F Determining what type of scrap to include in my internal PPM calculation Quality Manager and Management Related Issues 5
M Determining number of employees within the "Scope" of the QMS ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 9
A Determining the Scope of the QMS during Stage 1? Registrars and Notified Bodies 11
W Minor Audit Nonconformance Against Determining the scope of QMS IATF 16949 - Automotive Quality Systems Standard 12
D Determining Critical Components for conformity with IEC 60601-1 IEC 60601 - Medical Electrical Equipment Safety Standards Series 21
Q ISO 9001, section 4.3 Determining the scope of our QMS ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 9
R Determining Sample Size for Medical Device Component Validation Inspection, Prints (Drawings), Testing, Sampling and Related Topics 0
A What does 8.2.2.1, Determining the requirements related to products and services,mean IATF 16949 - Automotive Quality Systems Standard 1
A Determining Retention Period for Medical Device QMS documents Document Control Systems, Procedures, Forms and Templates 5
S Surveillance Sampling Test - Determining Sample Size Inspection, Prints (Drawings), Testing, Sampling and Related Topics 5
F ISO 9001:2015 4.3 - Determining the scope of the quality management system ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 7
B Standards Needed In House - Determining what standards are applicable Various Other Specifications, Standards, and related Requirements 3
W Determining Medical Device Classification in Mexico Other Medical Device Regulations World-Wide 5
K Determining Effect of Failure without a DFMEA (Design FMEA) FMEA and Control Plans 1
W Determining the Status and Importance of the Processes and Areas to be Audited Internal Auditing 7
T Determining Customer Requirements for the US Postal Service (USPS) IATF 16949 - Automotive Quality Systems Standard 4
Crimpshrine13 Rules of achieving and maintaining IATF recognition - Determining audit days IATF 16949 - Automotive Quality Systems Standard 2
R Developing procedure for Determining Company's Context And Interested Parties ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 53
W Determining Asset Life or Depreciation Life for M&TE General Measurement Device and Calibration Topics 1
N Reason for determining no adverse effect on reworked product ISO 13485:2016 - Medical Device Quality Management Systems 8
N Procedure for determining pinhole position in condom Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
alonFAI Determining PCBA Xray Test Sampling Size Statistical Analysis Tools, Techniques and SPC 1
S Determining sample size for inspection to achieve x% confidence re defects Misc. Quality Assurance and Business Systems Related Topics 10
S Determining Sample Size - AQL & LQ AQL - Acceptable Quality Level 10

Similar threads

Top Bottom