732A drift
I hope someone can help with a strange anomaly on either my 3458A or the
732A. The 732A 10V output as measured on my 3458A seems relatively stable
over time (it bounces around about +/-1 uV but is it the 732 or the 3458?).
However, the 1.000 VDC output drifts downward at a rate around 1-2 uV per
second as soon as I plug the 3458A into the 732 output. If I remove the
3458A and connect it back up after a few 10s of seconds, the reading goes
back to what it started at and then drifts downward again. The 1.018V
output also drifts downward but at a much slower rate and not as much. Now
the question is: is it the 732 or the 3458A? I tried to see it on my
Agilent 34401A DMM but it really doesn't have the resolution, but I do seem
to see it on the 1.000VDC output. If it is the 732A, what would cause it
to drift downward like that? Since the 3458A has an input impedance of
10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even see
the difference of whether the 3458A is connected of not, but it clearly
makes a difference as to how long its connected and how long it's been
disconnected.
Any one have any conjectures?
Also, what will turn on the "In Cal" light? What does it mean if it
doesn't come on?
Thanks,
Randy
Randy,
that is strange. two things come in mind that might be worth checking. first, is the mains frequency setting of the 3458a set to 60Hz (I assume you are in the US)? this is important to suppress mains ac disturbing the measurement.
secondly, have you connected guard? tsp cables would be best to use.
a general statment re. the 1V and 1.18V. they are much less stable than the 10V. My 732A e.g. has a drift of 0.2ppm/a. So I use a kelvin-varley divider if I need 1V. this is self calibrating, so you have maybe 0.1ppm worse accuracy. you could also use the 3458a linearity to re-characterize the 1v with reference to the 10V. That also gives you good accuracy. Also, I only have the 10V cal'ed on a regular basis to below 0.5ppm accuracy, that costs much less than haveing all three voltages cal'ed, which would not add any benefit anyway.
Adrian
Gesendet: Samstag, 23. August 2014 um 05:16 Uhr
Von: "Randy Evans" randyevans2688@gmail.com
An: "volt-nuts@febo.com" volt-nuts@febo.com
Betreff: [volt-nuts] 732A drift
I hope someone can help with a strange anomaly on either my 3458A or the
732A. The 732A 10V output as measured on my 3458A seems relatively stable
over time (it bounces around about +/-1 uV but is it the 732 or the 3458?).
However, the 1.000 VDC output drifts downward at a rate around 1-2 uV per
second as soon as I plug the 3458A into the 732 output. If I remove the
3458A and connect it back up after a few 10s of seconds, the reading goes
back to what it started at and then drifts downward again. The 1.018V
output also drifts downward but at a much slower rate and not as much. Now
the question is: is it the 732 or the 3458A? I tried to see it on my
Agilent 34401A DMM but it really doesn't have the resolution, but I do seem
to see it on the 1.000VDC output. If it is the 732A, what would cause it
to drift downward like that? Since the 3458A has an input impedance of
10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even see
the difference of whether the 3458A is connected of not, but it clearly
makes a difference as to how long its connected and how long it's been
disconnected.
Any one have any conjectures?
Also, what will turn on the "In Cal" light? What does it mean if it
doesn't come on?
Thanks,
Randy
volt-nuts mailing list -- volt-nuts@febo.com
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and follow the instructions there.
Randy,
I looked at the 3458a input impedance, and it is difficult to get the meter set to the FixedZ (10M) mode. However, the 100v range is 10M. It should default to HiZ on reset.
I forgot to mention to check the outputs and guard resistance to ground. One of my 732a had some foam baffling under the cover that had dry rotted. There was a lot of leakage to ground.
I can't remember if the foam was on the older or newer versions of the 732a.
The cal light comes on with a short wire stuck in the hole and connected to a LO output terminal. I don't know, but maybe the battery charge led has to be off.
Todd
Sent from my iPad
On Aug 23, 2014, at 1:16, Randy Evans randyevans2688@gmail.com wrote:
I hope someone can help with a strange anomaly on either my 3458A or the
732A. The 732A 10V output as measured on my 3458A seems relatively stable
over time (it bounces around about +/-1 uV but is it the 732 or the 3458?).
However, the 1.000 VDC output drifts downward at a rate around 1-2 uV per
second as soon as I plug the 3458A into the 732 output. If I remove the
3458A and connect it back up after a few 10s of seconds, the reading goes
back to what it started at and then drifts downward again. The 1.018V
output also drifts downward but at a much slower rate and not as much. Now
the question is: is it the 732 or the 3458A? I tried to see it on my
Agilent 34401A DMM but it really doesn't have the resolution, but I do seem
to see it on the 1.000VDC output. If it is the 732A, what would cause it
to drift downward like that? Since the 3458A has an input impedance of
10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even see
the difference of whether the 3458A is connected of not, but it clearly
makes a difference as to how long its connected and how long it's been
disconnected.
Any one have any conjectures?
Also, what will turn on the "In Cal" light? What does it mean if it
doesn't come on?
Thanks,
Randy
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
Randy,
The 'IN CAL' LED is turned on as Todd describes. It goes off if power to
the unit is lost and, thus, calibration is lost. It is not related to the
battery charge LED.
As I understand it, the units are designed to powered on 24/7/365 and are
'IN CAL' once they are powered up, stable (weeks, months?), and have been
calibrated by your reference lab. Once power is lost, meaning lost AC and
batteries depleted, the 'IN CAL' light goes out and outputs are thereafter
unreliable.
Once you decide to get the 732A calibrated, you will need to find a way to
ship it to the reference lab and get it shipped back while continuously
powered, connecting an external battery pack to the connector on the back of
the battery pack. The internal battery pack is likely to last only a few
hours.
There are at least two types of connectors for an external battery, two 5
way binding posts and a Hypertronics connector which is a small black
connector about 'dime' sized. I can find the part number for the mating
connector if you need it.
I think the +/- 1 uV drift with the 10 V output and the 3458A are within
specs for both the 732A and 3458A.
Not sure what to think about the drift on the other readings unless there is
some sort of 'dirt' on the 1 V and 1.018 V binding posts and/or ground.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Todd Micallef
Sent: Saturday, August 23, 2014 4:13 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A drift
Randy,
I looked at the 3458a input impedance, and it is difficult to get the meter
set to the FixedZ (10M) mode. However, the 100v range is 10M. It should
default to HiZ on reset.
I forgot to mention to check the outputs and guard resistance to ground. One
of my 732a had some foam baffling under the cover that had dry rotted. There
was a lot of leakage to ground.
I can't remember if the foam was on the older or newer versions of the 732a.
The cal light comes on with a short wire stuck in the hole and connected to
a LO output terminal. I don't know, but maybe the battery charge led has to
be off.
Todd
Sent from my iPad
On Aug 23, 2014, at 1:16, Randy Evans randyevans2688@gmail.com wrote:
I hope someone can help with a strange anomaly on either my 3458A or
the 732A. The 732A 10V output as measured on my 3458A seems
relatively stable over time (it bounces around about +/-1 uV but is it the
732 or the 3458?).
However, the 1.000 VDC output drifts downward at a rate around 1-2 uV
per second as soon as I plug the 3458A into the 732 output. If I
remove the 3458A and connect it back up after a few 10s of seconds,
the reading goes back to what it started at and then drifts downward
again. The 1.018V output also drifts downward but at a much slower
rate and not as much. Now the question is: is it the 732 or the
3458A? I tried to see it on my Agilent 34401A DMM but it really
doesn't have the resolution, but I do seem to see it on the 1.000VDC
output. If it is the 732A, what would cause it to drift downward like
that? Since the 3458A has an input impedance of
10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even
see
the difference of whether the 3458A is connected of not, but it
clearly makes a difference as to how long its connected and how long
it's been disconnected.
Any one have any conjectures?
Also, what will turn on the "In Cal" light? What does it mean if it
doesn't come on?
Thanks,
Randy
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and follow the instructions there.
The output impedance of both the 1v outputs is ~1k ohm. I wonder if Randy could check the 3458a input impedance with a 10M ohm resistor and the 10v output of the 732a.
I was thinking that the 732a needed a minimum battery voltage to allow the in cal led to turn on with the short to the Lo terminal. I guess I could try it on one of mine that is waiting for repair.
Todd
Sent from my iPad
On Aug 23, 2014, at 6:42, "J. L. Trantham" jltran@att.net wrote:
Randy,
The 'IN CAL' LED is turned on as Todd describes. It goes off if power to
the unit is lost and, thus, calibration is lost. It is not related to the
battery charge LED.
As I understand it, the units are designed to powered on 24/7/365 and are
'IN CAL' once they are powered up, stable (weeks, months?), and have been
calibrated by your reference lab. Once power is lost, meaning lost AC and
batteries depleted, the 'IN CAL' light goes out and outputs are thereafter
unreliable.
Once you decide to get the 732A calibrated, you will need to find a way to
ship it to the reference lab and get it shipped back while continuously
powered, connecting an external battery pack to the connector on the back of
the battery pack. The internal battery pack is likely to last only a few
hours.
There are at least two types of connectors for an external battery, two 5
way binding posts and a Hypertronics connector which is a small black
connector about 'dime' sized. I can find the part number for the mating
connector if you need it.
I think the +/- 1 uV drift with the 10 V output and the 3458A are within
specs for both the 732A and 3458A.
Not sure what to think about the drift on the other readings unless there is
some sort of 'dirt' on the 1 V and 1.018 V binding posts and/or ground.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Todd Micallef
Sent: Saturday, August 23, 2014 4:13 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A drift
Randy,
I looked at the 3458a input impedance, and it is difficult to get the meter
set to the FixedZ (10M) mode. However, the 100v range is 10M. It should
default to HiZ on reset.
I forgot to mention to check the outputs and guard resistance to ground. One
of my 732a had some foam baffling under the cover that had dry rotted. There
was a lot of leakage to ground.
I can't remember if the foam was on the older or newer versions of the 732a.
The cal light comes on with a short wire stuck in the hole and connected to
a LO output terminal. I don't know, but maybe the battery charge led has to
be off.
Todd
Sent from my iPad
On Aug 23, 2014, at 1:16, Randy Evans randyevans2688@gmail.com wrote:
I hope someone can help with a strange anomaly on either my 3458A or
the 732A. The 732A 10V output as measured on my 3458A seems
relatively stable over time (it bounces around about +/-1 uV but is it the
732 or the 3458?).
However, the 1.000 VDC output drifts downward at a rate around 1-2 uV
per second as soon as I plug the 3458A into the 732 output. If I
remove the 3458A and connect it back up after a few 10s of seconds,
the reading goes back to what it started at and then drifts downward
again. The 1.018V output also drifts downward but at a much slower
rate and not as much. Now the question is: is it the 732 or the
3458A? I tried to see it on my Agilent 34401A DMM but it really
doesn't have the resolution, but I do seem to see it on the 1.000VDC
output. If it is the 732A, what would cause it to drift downward like
that? Since the 3458A has an input impedance of
10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even
see
the difference of whether the 3458A is connected of not, but it
clearly makes a difference as to how long its connected and how long
it's been disconnected.
Any one have any conjectures?
Also, what will turn on the "In Cal" light? What does it mean if it
doesn't come on?
Thanks,
Randy
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https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
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and follow the instructions there.
Never mind. I tested it myself. You should be able to get the in cal led
working without batteries.
Todd
On Sat, Aug 23, 2014 at 7:20 AM, Todd Micallef tmicallef@gmail.com wrote:
The output impedance of both the 1v outputs is ~1k ohm. I wonder if Randy
could check the 3458a input impedance with a 10M ohm resistor and the 10v
output of the 732a.
I was thinking that the 732a needed a minimum battery voltage to allow the
in cal led to turn on with the short to the Lo terminal. I guess I could
try it on one of mine that is waiting for repair.
Todd
Sent from my iPad
On Aug 23, 2014, at 6:42, "J. L. Trantham" jltran@att.net wrote:
Randy,
The 'IN CAL' LED is turned on as Todd describes. It goes off if power to
the unit is lost and, thus, calibration is lost. It is not related to
the
battery charge LED.
As I understand it, the units are designed to powered on 24/7/365 and are
'IN CAL' once they are powered up, stable (weeks, months?), and have been
calibrated by your reference lab. Once power is lost, meaning lost AC
and
batteries depleted, the 'IN CAL' light goes out and outputs are
thereafter
unreliable.
Once you decide to get the 732A calibrated, you will need to find a way
to
ship it to the reference lab and get it shipped back while continuously
powered, connecting an external battery pack to the connector on the
back of
the battery pack. The internal battery pack is likely to last only a few
hours.
There are at least two types of connectors for an external battery, two 5
way binding posts and a Hypertronics connector which is a small black
connector about 'dime' sized. I can find the part number for the mating
connector if you need it.
I think the +/- 1 uV drift with the 10 V output and the 3458A are within
specs for both the 732A and 3458A.
Not sure what to think about the drift on the other readings unless
there is
some sort of 'dirt' on the 1 V and 1.018 V binding posts and/or ground.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Todd Micallef
Sent: Saturday, August 23, 2014 4:13 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A drift
Randy,
I looked at the 3458a input impedance, and it is difficult to get the
meter
set to the FixedZ (10M) mode. However, the 100v range is 10M. It should
default to HiZ on reset.
I forgot to mention to check the outputs and guard resistance to ground.
One
of my 732a had some foam baffling under the cover that had dry rotted.
There
was a lot of leakage to ground.
I can't remember if the foam was on the older or newer versions of the
732a.
The cal light comes on with a short wire stuck in the hole and connected
to
a LO output terminal. I don't know, but maybe the battery charge led has
to
be off.
Todd
Sent from my iPad
On Aug 23, 2014, at 1:16, Randy Evans randyevans2688@gmail.com wrote:
I hope someone can help with a strange anomaly on either my 3458A or
the 732A. The 732A 10V output as measured on my 3458A seems
relatively stable over time (it bounces around about +/-1 uV but is it
the
732 or the 3458?).
However, the 1.000 VDC output drifts downward at a rate around 1-2 uV
per second as soon as I plug the 3458A into the 732 output. If I
remove the 3458A and connect it back up after a few 10s of seconds,
the reading goes back to what it started at and then drifts downward
again. The 1.018V output also drifts downward but at a much slower
rate and not as much. Now the question is: is it the 732 or the
3458A? I tried to see it on my Agilent 34401A DMM but it really
doesn't have the resolution, but I do seem to see it on the 1.000VDC
output. If it is the 732A, what would cause it to drift downward like
that? Since the 3458A has an input impedance of
10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even
see
the difference of whether the 3458A is connected of not, but it
clearly makes a difference as to how long its connected and how long
it's been disconnected.
Any one have any conjectures?
Also, what will turn on the "In Cal" light? What does it mean if it
doesn't come on?
Thanks,
Randy
volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
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and follow the instructions there.
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To unsubscribe, go to
and follow the instructions there.
I think the 'IN CAL' LED has to do with a 'minimum voltage' but I don't
think it has to with a minimum battery voltage.
When you remove the battery pack, with the unit plugged in, I don't think
the 'IN CAL' LED goes out. Otherwise, you would never be able to swap
battery packs.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Todd Micallef
Sent: Saturday, August 23, 2014 6:21 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A drift
The output impedance of both the 1v outputs is ~1k ohm. I wonder if Randy
could check the 3458a input impedance with a 10M ohm resistor and the 10v
output of the 732a.
I was thinking that the 732a needed a minimum battery voltage to allow the
in cal led to turn on with the short to the Lo terminal. I guess I could try
it on one of mine that is waiting for repair.
Todd
Sent from my iPad
On Aug 23, 2014, at 6:42, "J. L. Trantham" jltran@att.net wrote:
Randy,
The 'IN CAL' LED is turned on as Todd describes. It goes off if power
to the unit is lost and, thus, calibration is lost. It is not related
to the battery charge LED.
As I understand it, the units are designed to powered on 24/7/365 and
are 'IN CAL' once they are powered up, stable (weeks, months?), and
have been calibrated by your reference lab. Once power is lost,
meaning lost AC and batteries depleted, the 'IN CAL' light goes out
and outputs are thereafter unreliable.
Once you decide to get the 732A calibrated, you will need to find a
way to ship it to the reference lab and get it shipped back while
continuously powered, connecting an external battery pack to the
connector on the back of the battery pack. The internal battery pack
is likely to last only a few hours.
There are at least two types of connectors for an external battery,
two 5 way binding posts and a Hypertronics connector which is a small
black connector about 'dime' sized. I can find the part number for
the mating connector if you need it.
I think the +/- 1 uV drift with the 10 V output and the 3458A are
within specs for both the 732A and 3458A.
Not sure what to think about the drift on the other readings unless
there is some sort of 'dirt' on the 1 V and 1.018 V binding posts and/or
ground.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]
On Behalf Of Todd Micallef
Sent: Saturday, August 23, 2014 4:13 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A drift
Randy,
I looked at the 3458a input impedance, and it is difficult to get the
meter set to the FixedZ (10M) mode. However, the 100v range is 10M. It
should default to HiZ on reset.
I forgot to mention to check the outputs and guard resistance to
ground. One of my 732a had some foam baffling under the cover that had
dry rotted. There was a lot of leakage to ground.
I can't remember if the foam was on the older or newer versions of the
732a.
The cal light comes on with a short wire stuck in the hole and
connected to a LO output terminal. I don't know, but maybe the battery
charge led has to be off.
Todd
Sent from my iPad
On Aug 23, 2014, at 1:16, Randy Evans randyevans2688@gmail.com wrote:
I hope someone can help with a strange anomaly on either my 3458A or
the 732A. The 732A 10V output as measured on my 3458A seems
relatively stable over time (it bounces around about +/-1 uV but is
it the
732 or the 3458?).
However, the 1.000 VDC output drifts downward at a rate around 1-2 uV
per second as soon as I plug the 3458A into the 732 output. If I
remove the 3458A and connect it back up after a few 10s of seconds,
the reading goes back to what it started at and then drifts downward
again. The 1.018V output also drifts downward but at a much slower
rate and not as much. Now the question is: is it the 732 or the
3458A? I tried to see it on my Agilent 34401A DMM but it really
doesn't have the resolution, but I do seem to see it on the 1.000VDC
output. If it is the 732A, what would cause it to drift downward
like that? Since the 3458A has an input impedance of
10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even
see
the difference of whether the 3458A is connected of not, but it
clearly makes a difference as to how long its connected and how long
it's been disconnected.
Any one have any conjectures?
Also, what will turn on the "In Cal" light? What does it mean if it
doesn't come on?
Thanks,
Randy
volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
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and follow the instructions there.
Joe,
You are correct. I was thinking that the 732A looked at two different
conditions to conrol the LED. It only looks at the "raw" dc output for the
LED.
Todd
On Sat, Aug 23, 2014 at 7:41 AM, J. L. Trantham jltran@att.net wrote:
I think the 'IN CAL' LED has to do with a 'minimum voltage' but I don't
think it has to with a minimum battery voltage.
When you remove the battery pack, with the unit plugged in, I don't think
the 'IN CAL' LED goes out. Otherwise, you would never be able to swap
battery packs.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On
Behalf Of Todd Micallef
Sent: Saturday, August 23, 2014 6:21 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A drift
The output impedance of both the 1v outputs is ~1k ohm. I wonder if Randy
could check the 3458a input impedance with a 10M ohm resistor and the 10v
output of the 732a.
I was thinking that the 732a needed a minimum battery voltage to allow the
in cal led to turn on with the short to the Lo terminal. I guess I could
try
it on one of mine that is waiting for repair.
Todd
Sent from my iPad
On Aug 23, 2014, at 6:42, "J. L. Trantham" jltran@att.net wrote:
Randy,
The 'IN CAL' LED is turned on as Todd describes. It goes off if power
to the unit is lost and, thus, calibration is lost. It is not related
to the battery charge LED.
As I understand it, the units are designed to powered on 24/7/365 and
are 'IN CAL' once they are powered up, stable (weeks, months?), and
have been calibrated by your reference lab. Once power is lost,
meaning lost AC and batteries depleted, the 'IN CAL' light goes out
and outputs are thereafter unreliable.
Once you decide to get the 732A calibrated, you will need to find a
way to ship it to the reference lab and get it shipped back while
continuously powered, connecting an external battery pack to the
connector on the back of the battery pack. The internal battery pack
is likely to last only a few hours.
There are at least two types of connectors for an external battery,
two 5 way binding posts and a Hypertronics connector which is a small
black connector about 'dime' sized. I can find the part number for
the mating connector if you need it.
I think the +/- 1 uV drift with the 10 V output and the 3458A are
within specs for both the 732A and 3458A.
Not sure what to think about the drift on the other readings unless
there is some sort of 'dirt' on the 1 V and 1.018 V binding posts and/or
ground.
Good luck.
Joe
-----Original Message-----
From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com]
On Behalf Of Todd Micallef
Sent: Saturday, August 23, 2014 4:13 AM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 732A drift
Randy,
I looked at the 3458a input impedance, and it is difficult to get the
meter set to the FixedZ (10M) mode. However, the 100v range is 10M. It
should default to HiZ on reset.
I forgot to mention to check the outputs and guard resistance to
ground. One of my 732a had some foam baffling under the cover that had
dry rotted. There was a lot of leakage to ground.
I can't remember if the foam was on the older or newer versions of the
732a.
The cal light comes on with a short wire stuck in the hole and
connected to a LO output terminal. I don't know, but maybe the battery
charge led has to be off.
Todd
Sent from my iPad
On Aug 23, 2014, at 1:16, Randy Evans randyevans2688@gmail.com wrote:
I hope someone can help with a strange anomaly on either my 3458A or
the 732A. The 732A 10V output as measured on my 3458A seems
relatively stable over time (it bounces around about +/-1 uV but is
it the
732 or the 3458?).
However, the 1.000 VDC output drifts downward at a rate around 1-2 uV
per second as soon as I plug the 3458A into the 732 output. If I
remove the 3458A and connect it back up after a few 10s of seconds,
the reading goes back to what it started at and then drifts downward
again. The 1.018V output also drifts downward but at a much slower
rate and not as much. Now the question is: is it the 732 or the
3458A? I tried to see it on my Agilent 34401A DMM but it really
doesn't have the resolution, but I do seem to see it on the 1.000VDC
output. If it is the 732A, what would cause it to drift downward
like that? Since the 3458A has an input impedance of
10Gohm on the 1 and 10 V ranges, I wouldn't think the 732 would even
see
the difference of whether the 3458A is connected of not, but it
clearly makes a difference as to how long its connected and how long
it's been disconnected.
Any one have any conjectures?
Also, what will turn on the "In Cal" light? What does it mean if it
doesn't come on?
Thanks,
Randy
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