Hello!
As you can read in my previous post, I'm watching for some meter...
I had found some Fluke's used meter..but I have some doubts about its
calibration: if I buy a meter that had lost its calibration, is posible to
"recalibrate" it at home, or I must ship it to a proper center?
Thank you!

Starflex wrote:
Hello!
[SNIP]

Uhm.. I've read the manual...and I think that isn't possible... :-(

Starflex wrote in message
...
Hello!
As you can read in my previous post, I'm watching for some meter...
I had found some Fluke's used meter..but I have some doubts about its
calibration: if I buy a meter that had lost its calibration, is posible to
"recalibrate" it at home, or I must ship it to a proper center?
Thank you!



See threads , titled Digital Voltmeter Calibration
and also Calibrate source how?
both last year

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:
[SNIP]

Ok, thank you a lot.
I'm sorry for this question : I don't know that you have already spoken
about this argument, I' m Italian (as you can see reading my post in poor
englih!) and I don't read often this newsgroup...!

Thank you a lot!!

On Wed, 14 Mar 2007 21:07:18 +0100, "Starflex" put
finger to keyboard and composed:

Hello!
As you can read in my previous post, I'm watching for some meter...
I had found some Fluke's used meter..but I have some doubts about its
calibration: if I buy a meter that had lost its calibration, is posible to
"recalibrate" it at home, or I must ship it to a proper center?
Thank you!

You can build your own single-chip precision voltage reference using
Maxim's MAX6350 (5.0V) or MAX6325 (2.5V):
http://pdfserv.maxim-ic.com/en/ds/MAX6325-MAX6350.pdf

"The MAX6325/MAX6341/MAX6350 are low-noise, precision voltage
references with extremely low, 0.5ppm/°C typical temperature
coefficients and excellent, ±0.02% initial accuracy. These devices
feature buried-zener technology for lowest noise performance.
Load-regulation specifications are guaranteed for source and sink
currents up to 15mA. Excellent line and load regulation and low output
impedance at high frequencies make them ideal for high-resolution
data-conversion systems up to 16 bits."

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Franc Zabkar wrote:

You can build your own single-chip precision voltage reference using
Maxim's MAX6350 (5.0V) or MAX6325 (2.5V):
http://pdfserv.maxim-ic.com/en/ds/MAX6325-MAX6350.pdf

"The MAX6325/MAX6341/MAX6350 are low-noise, precision voltage
references with extremely low, 0.5ppm/°C typical temperature
coefficients and excellent, ±0.02% initial accuracy. These devices
feature buried-zener technology for lowest noise performance.
Load-regulation specifications are guaranteed for source and sink
currents up to 15mA. Excellent line and load regulation and low output
impedance at high frequencies make them ideal for high-resolution

Ok, I had seen this chip, thank you for the link!

Franc Zabkar wrote in message
...
On Wed, 14 Mar 2007 21:07:18 +0100, "Starflex" put
finger to keyboard and composed:

Hello!
As you can read in my previous post, I'm watching for some meter...
I had found some Fluke's used meter..but I have some doubts about its
calibration: if I buy a meter that had lost its calibration, is posible
to
"recalibrate" it at home, or I must ship it to a proper center?
Thank you!

You can build your own single-chip precision voltage reference using
Maxim's MAX6350 (5.0V) or MAX6325 (2.5V):
http://pdfserv.maxim-ic.com/en/ds/MAX6325-MAX6350.pdf

"The MAX6325/MAX6341/MAX6350 are low-noise, precision voltage
references with extremely low, 0.5ppm/°C typical temperature
coefficients and excellent, ±0.02% initial accuracy. These devices
feature buried-zener technology for lowest noise performance.
Load-regulation specifications are guaranteed for source and sink
currents up to 15mA. Excellent line and load regulation and low output
impedance at high frequencies make them ideal for high-resolution
data-conversion systems up to 16 bits."

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

I would suggest a precision source like that plus a high precision resistor
to check your meter against, once a year , noting the results in a record,
also cross-checking all 3 with someone else's calibrated meter every now and
then , also recorded.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Starflex wrote:
Hello!
As you can read in my previous post, I'm watching for some meter...
I had found some Fluke's used meter..but I have some doubts about its
calibration: if I buy a meter that had lost its calibration, is posible to
"recalibrate" it at home, or I must ship it to a proper center?
Thank you!



You have the two choices already mentioned:

1. Compare your meter readings to those of a meter known to be calibrated.

2. Build an accurate voltage source.

In either case, you need only note the error and record it on a label
stuck to the back of the meter. In those very rare instances in which
the instrument's ultimate accuracy is required, simply correct the
reading using the recorded information.

I understand your concern, but I believe that digital multimeters tend
to hold their calibration extremely well, even with "rough" handling and
the passage of many years. It is quite unusual, but certainly not
impossible, that one will require recalibration. Meters given away as
promotional items by distributors (i.e., very cheap meters) compare very
favorably in accuracy with Wavetek, Fluke, and HP instruments.

There are other reasons to purchase quality instruments, of course.

Good luck.

Chuck

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Starflex wrote:
Hello!
As you can read in my previous post, I'm watching for some meter...
I had found some Fluke's used meter..but I have some doubts about its
calibration: if I buy a meter that had lost its calibration, is posible to
"recalibrate" it at home, or I must ship it to a proper center?
Thank you!


Depends on what you want to do with it.
If you're in an industrial situaiton, you don't have much choice but to
have it professionally calibrated...whether it needs it or not.
In the US, when ISO9000 started, management looked at the cost
of continuous calibration of EVERY peice of equipment in the plant and
dumped everything that wasn't absolutely necessary. Was a great couple
of years for hobbyists.

As for actual calibration...most of the time, if you stay away from the
bleeding edge of specs...a modern 3.x digit multimeter is always in
calibration or it's broke bad. If you have two different types of
meters, check them against one another. IF they're the same, they're
PROBABLY both ok.

Of course, all bets are off if someone has tried to "calibrate it"
without proper tools and experience.

Simplest thing is to checkit against another meter and not worry about
it. You'll want to do this at least once when you buy a used meter.
If you build calibration sources, then you have to worry about their
calibration.

For most of us, accuracy ain't what it's cracked up to be.
I have two 5.5 digit meters in the attic. Found I never needed the
resolution and all the noise in the last digits was more distracting
than helpful. When you want to know if a 9V battery is good, you
don't need much precision or accuracy.
mike

--
Return address is VALID!
Bunch-O-Stuff Forsale He
http://nm7u.tripod.com/homepage/sale.html