[volt-nuts] Traveling Standards

[WarrenS]

Bob

If you want something Kiss simple that will more than do what you're asking 
for.
Take an AGED & SELECTED 1n825 type zener. (or 1n827, 1n829)
Select a stable resistor that will apply it's measured  "Zero TC current" 
(which is generally between 4 and 9 ma),
at say 15.000  volts or whatever stable PS voltage you care to use.
Measure the zener's voltage and with only two parts Plus a PS and some fun 
Volt nut time you have a 6.2xxx volt reference.
If you're interested, I'll send you the zener, because I got a lot of them 
on EBay a long time ago when they where only 1 cent each.

ws

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[volt-nuts] Traveling Standards
Bob Smither smither at c-c-i.com

Fellow voltage aficionados ,

If this has already been discussed - my apologies.  I could not find
this topic in the past several months of list archives.

Like many of us, I have an ever growing collection of voltmeters and
related instruments.  Like the man with two clocks who is never sure of
the time, I now have enough volt meters to have doubts about all of them.

So - I was wondering if those on this list with really good voltage
measurement capabilities would be willing to help those of us without.

What I have in mind is creating a small voltage reference circuit based
on one of the many available IC references that is stable enough in both
time and temperature to use as a transfer standard.  I am thinking that
the actual voltage is not important, just the stability.  Using the ICs
that I am familiar with the actual reference voltage would be around 5,
7, or 10 volts.  Said reference would be mailed to a willing list member
who would record his reading of the reference and mail it back.

I don't have such a reference yet, but have breadboarded a couple and
the idea seems like it might work.

My first objective would be to obtain a reference that I could use to
get all my meters to agree.  Since the best meters I have are an HP3455A
(best accuracy about 20 - 40 ppm, and only for 24 hours) and an ancient
(but very usable) Fluke 883AB (best accuracy is 100ppm), I would be very
happy to have a reference that I could trust to 10ppm.

So - two questions for the list:

1.  Does this sound feasible?  Am I overlooking anything that would keep
me from being able to transfer a 10ppm known reference?

2.  Any list members that would be willing to help with this?  I
envision mailing a small package with the reference in it along with an
enclosed, postage paid, return box.  I am asking for a member that would
take the reference, apply power, let it warm up, record the room
temperature and the reference voltage to within 10ppm, and return it to
me.  If you prefer to respond off-list - smither at c-c-i.com.

BTW - I live in Friendswood, Texas (near Houston).  Any fellow nutters
close enough that I could hand deliver the reference?

Best regards,

Bob Smither