[volt-nuts] A Fluke 732A

[Tom Knox]

Charles thanks for an engaging dialog, I think we generally agree, but have different interpretations of several words. I see calibration as a set of rules and procedures that a group has agreed upon, that when followed will allow tractability and repeatability to an agreed upon standard. And in our discussion I have considered documentation to to part of that strict set of rules. So if a guy has his friend at Fluke calibrate his 732A on the JJA over the weekend and does not file the correct paper work in my humble opinion no claim of calibration can be made. Calibration is what you can prove not what you know. But when that guy returns to his lab with the standard he knows if function correctly is will perform to a certain level. To me, in my lab; that is enough. Metrology is an important part of my life, and I wish I had the time and money to go through all the various levels of documentation and accreditation in my lab. Unfortunately it is just not practical. What I have done is collect multiple standards that I compare frequently one another in addition to comparing them to outside standards when I have the opportunity and if they all agree with-in the range of uncertainty I am fairly confident I can trust them in my work. But that is what I know, not what I can prove, therefore I never make claims any instrument worked on in my lab is calibrated with the exception of some Time and Freq equipment, but that is for another discussion. I will be interest to know what path Michael Hong goes with as to whether to return or keep the Fluke 732A and what route he chooses to follow concerning calibration. I hope the conversation has aided your decisions, please keep us posted.

Thomas Knox



> Date: Mon, 10 Mar 2014 08:33:01 -0400
> To: volt-nuts at febo.com
> From: csteinmetz at yandex.com
> Subject: Re: [volt-nuts] A Fluke 732A
> 
> 
> >I have to side with Tom on this one. Accreditation only provides 
> >independant verifcation of processess and proceedures. It provides 
> >increased confidence (in both the human and statistical senses) in 
> >the service provided. It does not prove that your standard is correct.
> 
> Documentation and accreditation are two entirely different 
> things.  Documentation is keeping track of a quantified chain of 
> inference leading to a conclusion regarding the uncertainty of a 
> measurement.  If documentation has not been done, there is no basis 
> for ANY claim about the uncertainty of a measurement.
> 
> Accreditation is the process of evaluating and auditing someone's 
> procedures (including their documentation) by a third party.
> 
> Accreditation is not necessary to have a basis for a claim of the 
> bounds of uncertainty of a measurement, but documentation is.
> 
> Best regards,
> 
> Charles
> 
> 
> 
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