Fluke 760A meter calibrator

[David C. Partridge]

I'm considering the purchase of a 760A.

I have a few questions:

1) The basic accuracy is 0.1%. Does this mean that the selected output will
be within 0.1% of setting, or does it mean that the repeatability is within
0.1%? What I'm getting at is can this beast be used to calibrate (for
example) a 6.5 digit meter if you have the calibration error data, or are
you limited to 3.5 digit meters with this calibrator?

2) What would the likely cost be to get one of these calibrated?

3) If non-functional how hard are they to fix, and are the operation and
service manuals readily locatable?

Thanks

 

[Robert Baer]

I'm considering the purchase of a 760A.

I have a few questions:

1) The basic accuracy is 0.1%. Does this mean that the selected output will
be within 0.1% of setting, or does it mean that the repeatability is within
0.1%? What I'm getting at is can this beast be used to calibrate (for
example) a 6.5 digit meter if you have the calibration error data, or are
you limited to 3.5 digit meters with this calibrator?

2) What would the likely cost be to get one of these calibrated?

3) If non-functional how hard are they to fix, and are the operation and
service manuals readily locatable?

Thanks

I believe that if you bothered to read the specs, that "accuracy"
means that the output will be within the specified rating(s).
Fluk has had the habit of making instruments that are almost an order
of magnitude better - and that the instruments have virtually zero drift
if not abused.
Repeatability of almost any meter is usually an order of magnitude
better than the specs.
If you want manuals, ask the source: Fluke...

 

[David C. Partridge]

I did read the specs that I could find - they merely said accuracy 0.1%.

I looked on Fluke's web site, but they don't have anything covering the
760A, as that is now an OLD meter calibrator (not a meter) - probably 15-25
years old.

That's why I asked here!

It's comforting to know that their instruments typically well exceed
specification and that the repeatability will be even better, but this still
leaves my questions open.

Thanks for the input though.

Cheers
Dave

 

[Gary Schafer]

..1% isn't going to be of much use even for a 3 ½ digit meter as most
of them are better than .05%.

My Fluke 87-3 is .05% on DC and .7% on AC and that is a 3 ½ digit
meter.

A 6 ½ digit meter will have accuracies around .0005 or better.

..1 will only do for inexpensive meters.

73
Gary K4FMX

 

[David C. Partridge]

On the first take I'd be inclined to agree.

However, if the calibrator is consistent to the needed level, and the
calibration data (in terms of if set for 10V, the output is 10.000521V with
an uncertainty of 1 count) is known, then it should be possible to use it to
calibrate much higher specification equipment.

What is the typical specification of a calibrator used to calibrate 6.5
digit or better meters? I'm sure that calibration labs do not take all
these back to a primary standard (Josephson junction) and a Kelvin-Varley
divider for calibration! You'd probably do that for a transfer standard
(e.g. an 8.5 digit meter), but not for anything much less.

Are there any working metrologists watching who could cast some light on my
ignorance.

Thanks
Dave

 

[Sailor]

I'm considering the purchase of a 760A.

I have a few questions:

1) The basic accuracy is 0.1%. Does this mean that the selected output
will be within 0.1% of setting, or does it mean that the repeatability is
within
0.1%? What I'm getting at is can this beast be used to calibrate (for
example) a 6.5 digit meter if you have the calibration error data, or are
you limited to 3.5 digit meters with this calibrator?

2) What would the likely cost be to get one of these calibrated?

3) If non-functional how hard are they to fix, and are the operation and
service manuals readily locatable?

Thanks

Hi ,

To use a 760A for anything better than a 3.5 digit meter is dreaming of a
better world. Basic accuracy means that in the best of cases the output
will be within 0.1% of setting. Instruments to be calibrated with this unit
( in keeping with good calibration practis)should have a basic accuracy of
0.4 % or greater (eg meterman 34XR 0.5% + 1 digit) . You could naturaly
calibrate a 6.5 digit multi meter to 0.1 % spec.

As for repair. parts maybe be hard to find as this is a very old unit.

If you need to calibrate a few unit try to rent a fluke 5500 or beter a
5700.

If DC calibration is what you need check out a 335A also very old but basic
accuracy is 0.002 % witch is ok for you 6.5 digit Multi meter.

hope this helps ..