Solartron 7081
OK. Thanks for info that I did not know. I'll have to actually read the
manual.
After the first set, it ranged from 10.00001 to 10.00010. After the second
set of button pushes, it reads 10.00006 when connected to the 'black' face,
9.99995 when connected to the 'white' face unit, and 10.00046 when connected
to the 335A.
Now, the next question.
If you were to spend the money to get something calibrated, what would you
choose?
If you chose one of the voltage standards, you could use that to 'calibrate'
the meters, and, thus, the other standards. However, if you chose one of
the meters, you could use that to 'calibrate' the standards, and thus, the
other meters. And, another question, what, actually, can you get
'calibrated' on this list?
And, I agree with Dave. A man with one watch ........
Thanks in advance.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]On
Behalf Of gbusg
Sent: Friday, September 02, 2011 6:52 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
Hi Joe,
To display one more digit of resolution on your HP 3457A, do this:
- Press "DIGITS DISP"
- Press "6"
- Press "ENT"
For a more quiet reading, do this:
- Press "NPLC"
- Press "100"
- Press "ENT"
After several hours warm-up, be sure to run "ACAL ALL".
I'm guessing your HP 3457A might typically be within 10ppm at 10Vdc.
Possibly within 5ppm but not likely better than that due to drift and
stability issues.
For example, my 3457A has drifted 5ppm since last "CAL 10" (5 years ago).
Of course in your case there's the uncertainty of not knowing when your
instruments were last cal'd by previous owners.
It sounds like you're a prime candidate to participate in a VDC round-robin,
as the other fellows are now discussing and proposing?
Cheers!
Greg
----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Friday, September 02, 2011 5:02 PM
Subject: [volt-nuts] Solartron 7081, other meters, and some voltage
standards
I have been testing my 'new' 7081 and suspect I have arrived at the 'usual'
cross roads of what to believe.
I have two Fluke 731B's that I got from 'the site'. I replaced the battery
packs in months past and have left both on for the past 3 or 4 days along
with the 7081 and other meters, an HP 3478A and an HP 3457A, as well as a
Fluke 335A voltage standard set to 10.000000 volts, all from 'the site'.
Regarding the 731B's, one is a 'white' face and the other is a 'black' face
and both are set to 10V.
I left the 7081 connected to the 'black' face 731B, set to 7 X 9 (3.2s) in
'TRACK', and walked in to the shop to find it reading 10.000000. When
connected to the 'white' face 731B, it reads 9.999898 and, when connected to
the 335A, it reads 10.000392.
The 3478A reads 10.0001, 10.0000, and 10.0005, respectively. The 3457A
reads 10.0001, 10.0000, and 10.0005, respectively.
Soooooooo, what, if any, conclusions are reachable? I am tempted to believe
that the 'black' face 731B and the 7081 are correct. What are the odds?
Thanks in advance.
Joe
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Yeah, Joe, the "10.00006" 3457A reading you're seeing is very typical of
what I've seen before on other 3457As. They seem to drift more positive, at
a very slow pace. (By now they're very old and so their internal "cal"
references have aged nicely.) But do keep in mind that, due to other
short-term tempco and warm-up issues, I wouldn't trust the 3457A for
decisions any closer than approximately 5ppm of target at 10Vdc.
I'm guessing (but have no proof) that your 'black' face 731B might be very
stable - maybe significantly better than Fluke's published spec. If that
turns out to be the case, I'd be tempted to choose the 'black' 731B as the
device to transfer 10Vdc from another lab into my own lab.
I don't have any experience with the Solartron 7081, so I'd like to hear
from everybody (who's in the know about it). I'd also like to see its
datasheet and/or manual.
-Greg
----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Friday, September 02, 2011 6:36 PM
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
OK. Thanks for info that I did not know. I'll have to actually read the
manual.
After the first set, it ranged from 10.00001 to 10.00010. After the second
set of button pushes, it reads 10.00006 when connected to the 'black' face,
9.99995 when connected to the 'white' face unit, and 10.00046 when connected
to the 335A.
Now, the next question.
If you were to spend the money to get something calibrated, what would you
choose?
If you chose one of the voltage standards, you could use that to 'calibrate'
the meters, and, thus, the other standards. However, if you chose one of
the meters, you could use that to 'calibrate' the standards, and thus, the
other meters. And, another question, what, actually, can you get
'calibrated' on this list?
And, I agree with Dave. A man with one watch ........
Thanks in advance.
Joe
Hi Joe,
By far, send in a 731 as it is way more stable then the rest of what you have.
Personally, if the price isn't too bad I would send both 731's in for cal. Make
sure you ask for them to record what the values were before any adjustment was
done and to put that into your report when they return it. That way you could
start to build up a history of how the 731's behave. That is far more important
!
Bill....WB6BNQ
"J. L. Trantham" wrote:
OK. Thanks for info that I did not know. I'll have to actually read the
manual.
After the first set, it ranged from 10.00001 to 10.00010. After the second
set of button pushes, it reads 10.00006 when connected to the 'black' face,
9.99995 when connected to the 'white' face unit, and 10.00046 when connected
to the 335A.
Now, the next question.
If you were to spend the money to get something calibrated, what would you
choose?
If you chose one of the voltage standards, you could use that to 'calibrate'
the meters, and, thus, the other standards. However, if you chose one of
the meters, you could use that to 'calibrate' the standards, and thus, the
other meters. And, another question, what, actually, can you get
'calibrated' on this list?
And, I agree with Dave. A man with one watch ........
Thanks in advance.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]On
Behalf Of gbusg
Sent: Friday, September 02, 2011 6:52 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
Hi Joe,
To display one more digit of resolution on your HP 3457A, do this:
- Press "DIGITS DISP"
- Press "6"
- Press "ENT"
For a more quiet reading, do this:
- Press "NPLC"
- Press "100"
- Press "ENT"
After several hours warm-up, be sure to run "ACAL ALL".
I'm guessing your HP 3457A might typically be within 10ppm at 10Vdc.
Possibly within 5ppm but not likely better than that due to drift and
stability issues.
For example, my 3457A has drifted 5ppm since last "CAL 10" (5 years ago).
Of course in your case there's the uncertainty of not knowing when your
instruments were last cal'd by previous owners.
It sounds like you're a prime candidate to participate in a VDC round-robin,
as the other fellows are now discussing and proposing?
Cheers!
Greg
----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Friday, September 02, 2011 5:02 PM
Subject: [volt-nuts] Solartron 7081, other meters, and some voltage
standards
I have been testing my 'new' 7081 and suspect I have arrived at the 'usual'
cross roads of what to believe.
I have two Fluke 731B's that I got from 'the site'. I replaced the battery
packs in months past and have left both on for the past 3 or 4 days along
with the 7081 and other meters, an HP 3478A and an HP 3457A, as well as a
Fluke 335A voltage standard set to 10.000000 volts, all from 'the site'.
Regarding the 731B's, one is a 'white' face and the other is a 'black' face
and both are set to 10V.
I left the 7081 connected to the 'black' face 731B, set to 7 X 9 (3.2s) in
'TRACK', and walked in to the shop to find it reading 10.000000. When
connected to the 'white' face 731B, it reads 9.999898 and, when connected to
the 335A, it reads 10.000392.
The 3478A reads 10.0001, 10.0000, and 10.0005, respectively. The 3457A
reads 10.0001, 10.0000, and 10.0005, respectively.
Soooooooo, what, if any, conclusions are reachable? I am tempted to believe
that the 'black' face 731B and the 7081 are correct. What are the odds?
Thanks in advance.
Joe
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OK. Where would you send a 731B with a 'non-standard' battery pack for
calibration?
Fluke? Others?
I am in NW Florida.
Thanks,
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]On
Behalf Of WB6BNQ
Sent: Friday, September 02, 2011 8:21 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
Hi Joe,
By far, send in a 731 as it is way more stable then the rest of what you
have.
Personally, if the price isn't too bad I would send both 731's in for cal.
Make
sure you ask for them to record what the values were before any adjustment
was
done and to put that into your report when they return it. That way you
could
start to build up a history of how the 731's behave. That is far more
important
!
Bill....WB6BNQ
"J. L. Trantham" wrote:
OK. Thanks for info that I did not know. I'll have to actually read the
manual.
After the first set, it ranged from 10.00001 to 10.00010. After the
second
set of button pushes, it reads 10.00006 when connected to the 'black'
face,
9.99995 when connected to the 'white' face unit, and 10.00046 when
connected
to the 335A.
Now, the next question.
If you were to spend the money to get something calibrated, what would you
choose?
If you chose one of the voltage standards, you could use that to
'calibrate'
the meters, and, thus, the other standards. However, if you chose one of
the meters, you could use that to 'calibrate' the standards, and thus, the
other meters. And, another question, what, actually, can you get
'calibrated' on this list?
And, I agree with Dave. A man with one watch ........
Thanks in advance.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]On
Behalf Of gbusg
Sent: Friday, September 02, 2011 6:52 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
Hi Joe,
To display one more digit of resolution on your HP 3457A, do this:
- Press "DIGITS DISP"
- Press "6"
- Press "ENT"
For a more quiet reading, do this:
- Press "NPLC"
- Press "100"
- Press "ENT"
After several hours warm-up, be sure to run "ACAL ALL".
I'm guessing your HP 3457A might typically be within 10ppm at 10Vdc.
Possibly within 5ppm but not likely better than that due to drift and
stability issues.
For example, my 3457A has drifted 5ppm since last "CAL 10" (5 years ago).
Of course in your case there's the uncertainty of not knowing when your
instruments were last cal'd by previous owners.
It sounds like you're a prime candidate to participate in a VDC
round-robin,
as the other fellows are now discussing and proposing?
Cheers!
Greg
----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Friday, September 02, 2011 5:02 PM
Subject: [volt-nuts] Solartron 7081, other meters, and some voltage
standards
I have been testing my 'new' 7081 and suspect I have arrived at the
'usual'
cross roads of what to believe.
I have two Fluke 731B's that I got from 'the site'. I replaced the
battery
packs in months past and have left both on for the past 3 or 4 days along
with the 7081 and other meters, an HP 3478A and an HP 3457A, as well as a
Fluke 335A voltage standard set to 10.000000 volts, all from 'the site'.
Regarding the 731B's, one is a 'white' face and the other is a 'black'
face
and both are set to 10V.
I left the 7081 connected to the 'black' face 731B, set to 7 X 9 (3.2s) in
'TRACK', and walked in to the shop to find it reading 10.000000. When
connected to the 'white' face 731B, it reads 9.999898 and, when connected
to
the 335A, it reads 10.000392.
The 3478A reads 10.0001, 10.0000, and 10.0005, respectively. The 3457A
reads 10.0001, 10.0000, and 10.0005, respectively.
Soooooooo, what, if any, conclusions are reachable? I am tempted to
believe
that the 'black' face 731B and the 7081 are correct. What are the odds?
Thanks in advance.
Joe
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I have not yet read the manual. Can you educate me about the 'ACAL ALL'?
I presume that the 'calibration' standards loaded at the last official
calibration are stored and can be 'reloaded' when needed. Correct?
Thanks,
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of gbusg
Sent: Friday, September 02, 2011 6:52 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
Hi Joe,
.........
After several hours warm-up, be sure to run "ACAL ALL".
..........
I just noted that Agilent still lists calibration services for the 3457A as
still being available. Not so for the 3478A.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of J. L. Trantham
Sent: Friday, September 02, 2011 8:40 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
OK. Where would you send a 731B with a 'non-standard' battery pack for
calibration?
Fluke? Others?
I am in NW Florida.
Thanks,
Joe
Joe,
I would take the battery pack out if your worried about it. Its' really there
for 24 hour or less transfers within the same lab. Besides, if it is out of a
warranty period, I doubt Fluke would care. After all you own it, not them.
As I live in California, I have no idea about facilities in your area. There has
to be some worthwhile and reliable calibration labs in or around your location
and definitely some on the East Coast somewhere. There are plenty of companies
that support the space program in Florida and it would seem reasonable that there
may actually be a reasonable cal lab too.
If you look around you may find a way to make a connection in the most unlikely
places. For instance most Electric Power Companies have their own calibration
capabilities to handle all of their needs. They may well have a maintained DC
standard. Maybe you might know someone without realizing it.
You could ask Geller Labs ( http://www.gellerlabs.com/ ) [New York] if he would
compare your 731B against his 732. I know he will calibrate his product for
customers for a cost. Maybe he might do yours for a reasonable price.
Failing that, send it to Fluke. At least we all know they would know what they
are doing with their own product. I bet if you asked them, they would even do a
24 hour off/on test and tell you what the Hysteresis looks like. I think you
find it to be more than acceptable.
good luck,
Bill....WB6BNQ
"J. L. Trantham" wrote:
OK. Where would you send a 731B with a 'non-standard' battery pack for
calibration?
Fluke? Others?
I am in NW Florida.
Thanks,
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]On
Behalf Of WB6BNQ
Sent: Friday, September 02, 2011 8:21 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
Hi Joe,
By far, send in a 731 as it is way more stable then the rest of what you
have.
Personally, if the price isn't too bad I would send both 731's in for cal.
Make
sure you ask for them to record what the values were before any adjustment
was
done and to put that into your report when they return it. That way you
could
start to build up a history of how the 731's behave. That is far more
important
!
Bill....WB6BNQ
"J. L. Trantham" wrote:
OK. Thanks for info that I did not know. I'll have to actually read the
manual.
After the first set, it ranged from 10.00001 to 10.00010. After the
second
set of button pushes, it reads 10.00006 when connected to the 'black'
face,
9.99995 when connected to the 'white' face unit, and 10.00046 when
connected
to the 335A.
Now, the next question.
If you were to spend the money to get something calibrated, what would you
choose?
If you chose one of the voltage standards, you could use that to
'calibrate'
the meters, and, thus, the other standards. However, if you chose one of
the meters, you could use that to 'calibrate' the standards, and thus, the
other meters. And, another question, what, actually, can you get
'calibrated' on this list?
And, I agree with Dave. A man with one watch ........
Thanks in advance.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]On
Behalf Of gbusg
Sent: Friday, September 02, 2011 6:52 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
Hi Joe,
To display one more digit of resolution on your HP 3457A, do this:
- Press "DIGITS DISP"
- Press "6"
- Press "ENT"
For a more quiet reading, do this:
- Press "NPLC"
- Press "100"
- Press "ENT"
After several hours warm-up, be sure to run "ACAL ALL".
I'm guessing your HP 3457A might typically be within 10ppm at 10Vdc.
Possibly within 5ppm but not likely better than that due to drift and
stability issues.
For example, my 3457A has drifted 5ppm since last "CAL 10" (5 years ago).
Of course in your case there's the uncertainty of not knowing when your
instruments were last cal'd by previous owners.
It sounds like you're a prime candidate to participate in a VDC
round-robin,
as the other fellows are now discussing and proposing?
Cheers!
Greg
----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Friday, September 02, 2011 5:02 PM
Subject: [volt-nuts] Solartron 7081, other meters, and some voltage
standards
I have been testing my 'new' 7081 and suspect I have arrived at the
'usual'
cross roads of what to believe.
I have two Fluke 731B's that I got from 'the site'. I replaced the
battery
packs in months past and have left both on for the past 3 or 4 days along
with the 7081 and other meters, an HP 3478A and an HP 3457A, as well as a
Fluke 335A voltage standard set to 10.000000 volts, all from 'the site'.
Regarding the 731B's, one is a 'white' face and the other is a 'black'
face
and both are set to 10V.
I left the 7081 connected to the 'black' face 731B, set to 7 X 9 (3.2s) in
'TRACK', and walked in to the shop to find it reading 10.000000. When
connected to the 'white' face 731B, it reads 9.999898 and, when connected
to
the 335A, it reads 10.000392.
The 3478A reads 10.0001, 10.0000, and 10.0005, respectively. The 3457A
reads 10.0001, 10.0000, and 10.0005, respectively.
Soooooooo, what, if any, conclusions are reachable? I am tempted to
believe
that the 'black' face 731B and the 7081 are correct. What are the odds?
Thanks in advance.
Joe
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and follow the instructions there.
To invoke 'ACAL ALL':
- Press "Auto Cal"
- Press the 'down' arrow to scroll thru menu, stopping at "ACAL ALL"
- Press "ENT"
- Wait a couple of minutes while ACAL automatically re-generates new ACAL
correction constants.
Note: The 'down' arrow is below the LCD display area.
ACAL generates new temporary cal constants based on internal measurements.
For example it re-generates a digital correction constant for DCV gain so
that, despite DC circuit gain drift over time, the meter once again "sees"
the internal zener reference voltage as equal to the voltage it measured the
last time a Cal Lab performed digital adjustment (of your 3457A against
external standards including a precision voltage reference). In other words,
immediately after ACAL, your 3457A error at 10Vdc will mostly be a function
of the drift of its internal zener voltage reference. Drift due to other
causes will mostly be subtracted-out during ACAL.
ACAL is invoked by (and is the responsibility of) the end-user.
Digital Calibration (against external standards) is a different thing, not
to be invoked unless one has access to the right, precision standards.
Now that we know you didn't invoke ACAL yet, it will be interesting to see
how different the results are. (They will be different.)
Let us know.
Greg
----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "'Discussion of precise voltage measurement'" volt-nuts@febo.com
Sent: Friday, September 02, 2011 8:28 PM
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
I have not yet read the manual. Can you educate me about the 'ACAL ALL'?
I presume that the 'calibration' standards loaded at the last official
calibration are stored and can be 'reloaded' when needed. Correct?
Thanks,
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of gbusg
Sent: Friday, September 02, 2011 6:52 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
Hi Joe,
.........
After several hours warm-up, be sure to run "ACAL ALL".
..........
volt-nuts mailing list -- volt-nuts@febo.com
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https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
Joe,
After looking at the Spec page for Solartron 7081 (as found at ko4bb per a
previous post by David Partridge) I find the Solartron to be very
interesting.
Again, I don't have personal experience with it, but my thinking is that, of
the instruments you've collected, your Solartron 7081 might actually be the
most stable at 10Vdc. Certainly it has the tightest spec: 4.3 ppm 2nd year
after calibration. Given the probable age of your 7081, I can imagine that
its 10Vdc aging might indeed have slowed way down (to a very desirable slow
creep)?
If any Solartron 7081 users are in the group, please chime-in with your
experiences regarding its observed stability at 10Vdc.
Cheers!
Greg
Here's a copy of David's link to the Solartron manuals at ko4bb:
http://www.ko4bb.com/cgi-bin/manuals.pl?dir=09%29_Misc_Test_Equipment/Solartron
Hard copy from Telford Electronics in the UK (a photocopy, but not quite as
up to date as the scan on Didier's web site).
Visit also <www.perdrix.co.uk> for a blog on repairing one of these.
Regards,
David Partridge
----- Original Message -----
From: "J. L. Trantham" jltran@att.net
To: "Discussion of precise voltage measurement" volt-nuts@febo.com
Sent: Friday, September 02, 2011 6:36 PM
Subject: Re: [volt-nuts] Solartron 7081, other meters,and some voltage
standards
OK. Thanks for info that I did not know. I'll have to actually read the
manual.
After the first set, it ranged from 10.00001 to 10.00010. After the second
set of button pushes, it reads 10.00006 when connected to the 'black' face,
9.99995 when connected to the 'white' face unit, and 10.00046 when connected
to the 335A.
Now, the next question.
If you were to spend the money to get something calibrated, what would you
choose?
If you chose one of the voltage standards, you could use that to 'calibrate'
the meters, and, thus, the other standards. However, if you chose one of
the meters, you could use that to 'calibrate' the standards, and thus, the
other meters. And, another question, what, actually, can you get
'calibrated' on this list?
And, I agree with Dave. A man with one watch ........
Thanks in advance.
Joe
Joe wrote:
I have been testing my 'new' 7081
* * *
I have two Fluke 731B's
an HP 3478A and an HP 3457A, as well as a
Fluke 335A
* * *
Soooooooo, what, if any, conclusions are reachable? I am tempted to believe
that the 'black' face 731B and the 7081 are correct. What are the odds?
Others have indicated what sort of stability you might expect from
some of these, assuming that they have not been adjusted (or
otherwise molested) since their last traceable calibration. However,
from what you have said about their provenance, you have no way of
knowing who's been "calibrating" or adjusting any of these, or when,
or what standards were used. So you have no basis for any belief
about which, if any, of them is "correct."
If you are going to have just one of them calibrated by a standards
lab, you should calibrate the most stable one. The 731s should be
the most stable of that bunch. Ideally, you should ship a 731 "hot"
(under battery power) to the lab, and the lab should return it hot,
so that there are no issues with power-cycle hysteresis (note that
the 731's successor, the 732, which uses the same reference element,
is only guaranteed to remain in cal if it has been under continuous
power since calibration).
Best regards,
Charles