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Kiss Analog butthurt over Dave getting free stuff

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nctnico:
Don't forget calibration is not just about accuracy of measurements but also means subjecting an instrument to a (limited) functional test.

joeqsmith:

--- Quote from: nctnico on November 23, 2023, 11:35:50 pm ---Don't forget calibration is not just about accuracy of measurements but also means subjecting an instrument to a (limited) functional test.

--- End quote ---

I would say it's pretty much a full on functional test.  Then again, I am sure we all have some horror stories when it comes to calibration houses. 

Someone:

--- Quote from: joeqsmith on November 24, 2023, 04:35:23 am ---
--- Quote from: nctnico on November 23, 2023, 11:35:50 pm ---Don't forget calibration is not just about accuracy of measurements but also means subjecting an instrument to a (limited) functional test.
--- End quote ---
I would say it's pretty much a full on functional test.  Then again, I am sure we all have some horror stories when it comes to calibration houses.
--- End quote ---
For a meter it is pretty typical to have at least one test recorded against every range. But more complex instruments such as scopes only have some of their parameters verified (and/or listed as warranted in the specifications), say channel to channel crosstalk for instance being unwarranted and untested. Or bandwidth, warranted, but untested in different voltage ranges.

joeqsmith:

--- Quote from: Someone on November 24, 2023, 05:21:27 am ---For a meter it is pretty typical to have at least one test recorded against every range. But more complex instruments such as scopes only have some of their parameters verified (and/or listed as warranted in the specifications), say channel to channel crosstalk for instance being unwarranted and untested. Or bandwidth, warranted, but untested in different voltage ranges.

--- End quote ---

Looking at my last report for my old Wavemaster scope, it looks like 43 parameters were verified by the factory.  I would say that's a fairly exhaustive test. Again, the idea is to prove that  the equipment still meets the manufacture's specifications.  That means all of them, not a few selected ones.

From listening to that video, it seemed Dave made a big deal out of calibration where the presenter felt they could just use what ever lab they like.   Maybe that's fine, maybe not.  As I said, I am sure we all have some horror stories when it comes to calibration.   Higher end equipment I would tend to return to the manufacture knowing they have any specialized test jigs, software, equipment required to do a proper job of it.   

joeqsmith:
For the bandwidth you mentioned,  the factory tests all four channels at nine different voltage levels, not one.  Mine is an 8500A which is spec'ed to 5GHz.  So they test at 5.001GHz and make sure the signal is higher than -3dB.  They also look at flatness.   These tests give me some idea how far I can push the scope.  For example, a few weeks ago I posted a screen shot from this scope where I excited a 6GHz filter with a pulse: 

https://www.eevblog.com/forum/testgear/show-us-your-square-wave/msg5163876/#msg5163876

During the video, he talks a lot about his background in power supplies.  True or not, doesn't really mater but I doubt many people would want a scope like mine for that sort of work.  I have a lower end (well, all my scopes are used and very old so...)   that I use for the majority of my experimenting.   Point being, he may consider $5kUSD a very high end scope and there is no need for anything better.  Something like the electrician who wrote me how there was never any need to look at signals beyond 60Hz.  That's the world he lives in, even though our voices and ears work at much higher frequencies.    :-DD

****
Thinking about reviews, I have not seen this particular person do it, but I have seen others call Dave a snob when it comes to recommendations he makes regarding handheld multi-meters.  When it comes to oscilloscopes, this person may view the use of higher end ones being a bit of a snob as well.   He may be totally ignorant about their applications. 

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