luciano
20th December 2006, 09:48 AM
Hello all of you,
Can somebody explain to me the relation between calibration an RR study ?
I really don’t understand it.
Right now I am in charge to do a in house calibration procedure, an I need your help because I really don’t know which are the stages of this procedure.
Thank you very much.
God bless you and a Happy Christmas
Jim Wynne
20th December 2006, 09:59 AM
Hello all of you,
Can somebody explain to me the relation between calibration an RR study ?
I really don’t understand it.
Right now I am in charge to do a in house calibration procedure, an I need your help because I really don’t know which are the stages of this procedure.
Thank you very much.
God bless you and a Happy Christmas
It's really pretty simple. "Calibration" is comparison of a measurement device to an accepted standard. It confirms that the gage is capable of working as designed, to accepted levels of accuracy and precision.
R&R (and other forms of MSA--measurement system analysis) is used to determine whether or not a given device is appropriate for the intended application. A tape measure may be calibrated to determine whether or not its graduation markings are accurate as compared to a standard. The fact that it is acceptable in that regard doesn't mean that it will be appropriate to use in all applications.
luciano
20th December 2006, 10:21 AM
It's really pretty simple. "Calibration" is comparison of a measurement device to an accepted standard. It confirms that the gage is capable of working as designed, to accepted levels of accuracy and precision.
R&R (and other forms of MSA--measurement system analysis) is used to determine whether or not a given device is appropriate for the intended application. A tape measure may be calibrated to determine whether or not its graduation markings are accurate as compared to a standard. The fact that it is acceptable in that regard doesn't mean that it will be appropriate to use in all applications.
thank you very much.
Some advices for calibration procedure stages ?
Jim Wynne
20th December 2006, 10:33 AM
thank you very much.
Some advices for calibration procedure stages ?
You're welcome. Use the Search function--you'll find lots of information on calibration and calibration procedures. You can start with the list of related threads down near the bottom of this page. Then, if you have specific questions, please post back and we'll be glad to help.
martin elliott
20th December 2006, 10:38 AM
If you are at the start of structuring a calibration laboratory from a clean start then perhaps ISO17025 and ISO5725 can provide some guidence.
It certainly won't be harmful to read up principals.
DsqrdDGD909
20th December 2006, 11:40 AM
What kind of measuring device(s) and for what application(s)?
luciano
29th December 2006, 04:55 PM
What kind of measuring device(s) and for what application(s)?
It's a torque screw. I need to calibrate in-house this torque screw. I never did it before and I need some advice.
It' necesary to introduce in my procedure a chapter about R&R study ?
tank you very much
God bless you in this new year.
Happy new year
Hershal
29th December 2006, 09:02 PM
I would not include a section abut R&R, but certainly would about measurement uncertainty.....
For a calibration to be considered traceable, two things are required: (1) an unbroken chain of comparison to National or international standards; and (2) stated uncertainty at each step.
The unbroken chain will only require documenting the link to the calibration standard by including the description or number of the calibration standard, its next calibration due date, and the certificate number from its last calibration.
The uncertainty can be calculated for the type of application or for each specific calibration.....I would examine how many of the calibrations are to be done in order to decide which to do.
The uncertainty tells you how much error exists in the calibration and what the error is.....it includes the calibration standard, the instrument being calibrated, environmental conditions, and any other influences that might affect the measurement.
As for procedure steps, I would start with a visual and functional check of the instrument; required items to effect the calibration; connections or similar; the specific tasks to effect the calibration; documentation including traceability and uncertainty.
Also, obtain a copy of The Metrology Handbook, available from ASQ.
http://www.asq.org
Hope this helps.
Hershal
luciano
30th December 2006, 09:03 AM
Thank you very much. Your informations are verry precious for me.
luciano
4th January 2007, 06:08 AM
I would not include a section abut R&R, but certainly would about measurement uncertainty.....
For a calibration to be considered traceable, two things are required: (1) an unbroken chain of comparison to National or international standards; and (2) stated uncertainty at each step.
The unbroken chain will only require documenting the link to the calibration standard by including the description or number of the calibration standard, its next calibration due date, and the certificate number from its last calibration.
The uncertainty can be calculated for the type of application or for each specific calibration.....I would examine how many of the calibrations are to be done in order to decide which to do.
The uncertainty tells you how much error exists in the calibration and what the error is.....it includes the calibration standard, the instrument being calibrated, environmental conditions, and any other influences that might affect the measurement.
As for procedure steps, I would start with a visual and functional check of the instrument; required items to effect the calibration; connections or similar; the specific tasks to effect the calibration; documentation including traceability and uncertainty.
Also, obtain a copy of The Metrology Handbook, available from ASQ.
http://www.asq.org
Hope this helps.
Hershal
May I have few questions ?
What do you mean by :
1. connections or similar ?
2. the specific tasks to effect the calibration ?
Also:
1. It’ s OK to do a check sheet for specific task to effect the calibration (for example: humidity required, maintenance, etc…?????
2. what are the maximum deviation admissible between measured value and indicated value ?
3. what I need to do when I found deviations above admissible limit
Thank you very much for your time.
God bless you.