Hello, Ed. I've inserted responses below.
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK
On 2019-04-20 20:50, Edward Price wrote:
*John:*
**
**
*I don’t see how a test house can “impose” compliance.*
*I thought all they could do was perform testing, and by looking at
the results of the testing, declare compliance.*
*JMW: People take or send an EUT to the test house, which finds that it
fails. They descend on it with ferrites, copper tape, capacitors,
unicorn poo (rarely) until it passes. That's what I mean by 'imposing'*
**
**
*You also ask “how can a company know that the result is reliable?”*
*Isn’t that the entire justification for accreditation of a test lab
by a 3rd party? *
*JMW: Yes, but we are talking in the context of that process failing;
test technicians who do not know, or do not apply, the procedures or the
standards well enough. Accreditation cannot operate continuously*
*I have had “expert customers” where they were so involved in the
compliance process that they had their own QA representative sit in my
lab and check off each step of a detailed, written test procedure as
each step was started and completed. *
*JMW: I guess they had bad experiences of the type we are discussing in
the past.*
*OTOH, a majority of my customers would say something like “call us
when you know if we have passed.” When a lab customer is not qualified
to determine the experience and capabilities of a test lab, the
customer can increase his chances of reliable results by using a test
lab that has had their facilities, people, procedures and support
processes reviewed by an organization that specializes in the review
of test labs.*
*JMW: that is the intention, but we are talking about the breakdown of
that process.*
**
**
*In the example that started all this, I assumed the test lab was an
accredited facility. As the test lab’s product proved to be
unreliable, there was a breakdown of the test lab’s operations. That
breakdown was supposed to have been made vanishingly improbable by the
blessing of that test lab by an accreditation authority. I suppose
that would mean that the accreditation authority’s process thus also
broke down. I guess we then have to question the accreditation
accreditors who accredited the test lab accreditors.*
*JMW: The accreditation might have been defective (we have had reports
of that). It could be perfect but the test house management allowed
laxity to compromise the actual testing.*
**
**
*Sorry for making the chain of accreditation sound comical. I suppose
you know a lot more than me about the efficacy of 3^rd party oversight
in ensuring reliable results. Can you elaborate just a bit about the
amount the reliability should increase when a customer chooses an
accredited test lab over an unaccredited test lab (assuming that was
possible if the standard didn’t make accredited test labs a
pre-condition)? Does the additional oversight layer (the
accreditation) increase performance reliability by perhaps 1 or 2
Sigmas or some percentage?*
*JMW: I'm sure I don't know more than you! For me, there is no useful
answer to your question. Less than perfect accredited labs have been
shown to exist. Labs that are not accredited may be extremely reliable;
for new technologies or new frequency ranges, the standards may be
available but accreditation may not be available when the first products
are submitted for testing.*
**
**
*Thanks!*
**
**
*/Ed Price
/**WB6WSN**/
/**Chula Vista, CA USA*
**
*From:*John Woodgate [mailto:[email protected]]
*Sent:* Friday, April 19, 2019 1:19 PM
*To:* [email protected]
*Subject:* Re: [PSES] Question re: Measuring a signal in a noisy
environment
I doubt anyone would disagree with that. But if a company allows a
test house to impose compliance, how can it know that the result is
reliable?
Best wishes
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk <http://www.woodjohn.uk>
Rayleigh, Essex UK
On 2019-04-19 21:09, Grasso, Charles wrote:
With all due respect I made a different text section:
*“Ultimately, I sold _reliable_ answers..” *(underline added by me)
That is all I am looking for as a customer.
Thanks!
Charles Grasso
W: 303-706-5467
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