Empathy List Archives

PK

Poul-Henning Kamp

Mon, Sep 5, 2011 4:05 PM

I finally had a chance to drop my HP3458A into a friendly Cal-lab and since
the last sticker on it says it is due for calibration in "2-1996" we are
talking seriously overdue calibration.

The result:
Internal 40K resistor: -11.66ppm
Internal 7V Voltage ref: -28.96ppm

That's not too shabby over 15 years...

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

I finally had a chance to drop my HP3458A into a friendly Cal-lab and since the last sticker on it says it is due for calibration in "2-1996" we are talking seriously overdue calibration. The result: Internal 40K resistor: -11.66ppm Internal 7V Voltage ref: -28.96ppm That's not too shabby over 15 years... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

PK

Poul-Henning Kamp

Tue, Sep 6, 2011 4:58 PM

In message 2783.1315238745@critter.freebsd.dk, Poul-Henning Kamp writes:

I finally had a chance to drop my HP3458A into a friendly Cal-lab and since
the last sticker on it says it is due for calibration in "2-1996" we are
talking seriously overdue calibration.

The result:
Internal 40K resistor: -11.66ppm
Internal 7V Voltage ref: -28.96ppm

That's not too shabby over 15 years...

Update:

Greg Burnett and I have been chatting offline, and it transpires,
based on the serial number of 2823A00556, that it is more like 22
years.

Appearantly this instrument was never calibrated after it left
the factory in late 1988 or early 1989.

The stickers say "Next test" (in german), they give no hint that
a calibration has happened, and the CALNUM? was 5 when I received
the meter, consistent with the factory calibration.

Further more, we probably didn't let the meter acclimatize long
enough yesterday, so in particular the 7V cal may be a couple of
PPM off (didn't want to overstay my welcome).

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

In message <2783.1315238745@critter.freebsd.dk>, Poul-Henning Kamp writes: >I finally had a chance to drop my HP3458A into a friendly Cal-lab and since >the last sticker on it says it is due for calibration in "2-1996" we are >talking seriously overdue calibration. > >The result: > Internal 40K resistor: -11.66ppm > Internal 7V Voltage ref: -28.96ppm > >That's not too shabby over 15 years... Update: Greg Burnett and I have been chatting offline, and it transpires, based on the serial number of 2823A00556, that it is more like 22 years. Appearantly this instrument was never calibrated after it left the factory in late 1988 or early 1989. The stickers say "Next test" (in german), they give no hint that a calibration has happened, and the CALNUM? was 5 when I received the meter, consistent with the factory calibration. Further more, we probably didn't let the meter acclimatize long enough yesterday, so in particular the 7V cal may be a couple of PPM off (didn't want to overstay my welcome). -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

AJ

Andreas Jahn

Tue, Sep 6, 2011 9:33 PM

The result:
Internal 40K resistor: -11.66ppm
Internal 7V Voltage ref: -28.96ppm

That's not too shabby over 15 years...

Update:

Greg Burnett and I have been chatting offline, and it transpires,
based on the serial number of 2823A00556, that it is more like 22
years.

Appearantly this instrument was never calibrated after it left
the factory in late 1988 or early 1989.

Hello Paul,

If the last cal was really before 1.1.1990 remember that the
official volt has been redefined at 1.1.1990 by +8.06 ppm.
So all readings which were made before have to be corrected by -8.06ppm.

With best regards

Andreas

>>The result: >> Internal 40K resistor: -11.66ppm >> Internal 7V Voltage ref: -28.96ppm >> >>That's not too shabby over 15 years... > > Update: > > Greg Burnett and I have been chatting offline, and it transpires, > based on the serial number of 2823A00556, that it is more like 22 > years. > > Appearantly this instrument was never calibrated after it left > the factory in late 1988 or early 1989. Hello Paul, If the last cal was really before 1.1.1990 remember that the official volt has been redefined at 1.1.1990 by +8.06 ppm. So all readings which were made before have to be corrected by -8.06ppm. With best regards Andreas

PK

Poul-Henning Kamp

Wed, Sep 7, 2011 8:52 AM

In message 33473809FD874529A25FBD3D6B6EB55E@laptop, "Andreas Jahn" writes:

If the last cal was really before 1.1.1990 remember that the
official volt has been redefined at 1.1.1990 by +8.06 ppm.
So all readings which were made before have to be corrected by -8.06ppm.

Now things get interesting: the 8.06 was for "most other countries",
but for US it was 9.26 PPM.

Does anybody know if HP calibrated 3458A's going to europe differently
from those going to USA ?

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

In message <33473809FD874529A25FBD3D6B6EB55E@laptop>, "Andreas Jahn" writes: >If the last cal was really before 1.1.1990 remember that the >official volt has been redefined at 1.1.1990 by +8.06 ppm. >So all readings which were made before have to be corrected by -8.06ppm. Now things get interesting: the 8.06 was for "most other countries", but for US it was 9.26 PPM. Does anybody know if HP calibrated 3458A's going to europe differently from those going to USA ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

volt-nuts@lists.febo.com

HP3458A _really_ long term stability