Re: Calibration equipment design

VMI wrote:

Michael A. Terrell wrote:
VMI wrote:
VMI wrote:
Hi,
Those calibration equipment costs you an arm and a leg, so I was
thinking in building my own.
I guess the equipment manufacturers did the same a long time ago to have
a reliable source to compare their equipment with.
But, how can one be sure that the unit you build is good?

With what to start with?
A voltage source: AC, DC. Just a few volts?
An amplifier with an exact known amplification, like x1, x10, x100?
A nice stable frequency source with exact dividers, x1, x10, x100?

That would be a good starting point I think.

Any idea's, comments and links and hints are welcome.

Zilog
Thanks for the replies,

Reactions:
"If you need to ask, you shouldn't be building it. "

What did you do when you build your first electronic whatever?
You just designed and built it?
I think you asked or looked for info to...

"They cost that much in part because they are traceable to NIST. It
will cost you an arm and a leg to build traceable equipment -
secondary standards are pricey, and keeping those standards traceable
is pricey."

I like to make clear that I do not want to have the equipment to be to
the NIST standards as this is a bit to extreme.
An above standard precision is ok.

"You'll find lots of good deals on older calibrations standards
on flea bay. Years ago I bought a very nice Fluke voltage/current
standard for $50."

That's an option and worth considering.

I ask myself" how did the first test equipment mfg's started to
calibrate and continue to compare the rest of their production with the
first?
It all started somewhere and with an average precision (as precision had
still to be invented).


It may have started out simple over 100 years ago, but now if it
isn't traceable to NIST, it isn't calibrated.


Again you're correct; if only you want to manufacture test equipment and
sell them.
But here it is for a limited use. We like to calibrate our instruments
by our self and not at a price.


That is ok for home brew projects, but not for professional work


It may be exaggerated to some but it is not for us.
Making electronic equipment or calibration standards do not differ much,
except the precision.
And for the later we do not have much expertise.
We prefer to build it by ourself (and for ourself!) so we know what we
are doing.
As written before: getting some on eg Ebay may be an option, but how do
we know they are correct and precise?


You have them calibrated as primary, or secondary standards like
everyone else. You can't just set your own arbitrary standards.


Back to square one I would say...
Getting the calibrators calibrated by a NIST recognized institute?


Its the only way to fly!


Zilog


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
.

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