Extech AC/DC Clamp Meter Offset

  • Thread starter Samuel M. Goldwasser
  • Start date
In article <hbuygam1.fsf@repairfaq.org>,
Samuel M. Goldwasser <sam@repairfaq.org> wrote:
I have an Extech 380652 that seems to work well in general but has
an approximately 0.06 A offset in the AC Amps mode on the 20 A range.

The user offset adjust pot only works on DC Amps.

Does anyone know if any of the 3 pots inside are for the AC amps offset?
Click to expand...
0.3% of FSD error? Isn't that quite good for this sort of device? One I
have is quoted at +/-2%. Of course with a constant error there's always
the temptation to sort it out.

But looking at the spec of that one, it's +/- 1.2%FS

--
*Avoid clichés like the plague. (They're old hat.) *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
Jamie <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> writes:

Arfa Daily wrote:

"Samuel M. Goldwasser" <sam@repairfaq.org> wrote in message
news:hbuygam1.fsf@repairfaq.org...

I have an Extech 380652 that seems to work well in general but has
an approximately 0.06 A offset in the AC Amps mode on the 20 A range.

The user offset adjust pot only works on DC Amps.

Does anyone know if any of the 3 pots inside are for the AC amps offset?

Thanks!

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Not just extraneous pickup from building wiring maybe ? Probably
not, but just a thought ...
Arfa
The op should be lucky its down that low on AC.

I have an extech my self (different model), that seems to have
a undocumented feature that appears to calibrate the AC mode of the
clamp when I hold down one of the buttons for like 4 secs or more.
Click to expand...
This is a pretty basic model, no buttons, only 3 slide switches.

And to Arfa's question, no not stray fields. :)

Thanks!

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
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Arfa Daily wrote:

"Samuel M. Goldwasser" <sam@repairfaq.org> wrote in message
news:hbuygam1.fsf@repairfaq.org...

I have an Extech 380652 that seems to work well in general but has
an approximately 0.06 A offset in the AC Amps mode on the 20 A range.

The user offset adjust pot only works on DC Amps.

Does anyone know if any of the 3 pots inside are for the AC amps offset?

Thanks!

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/



Not just extraneous pickup from building wiring maybe ? Probably not, but
just a thought ...

Arfa


The op should be lucky its down that low on AC.
Click to expand...

I have an extech my self (different model), that seems to have
a undocumented feature that appears to calibrate the AC mode of the
clamp when I hold down one of the buttons for like 4 secs or more.
 
"Samuel M. Goldwasser" <sam@repairfaq.org> wrote in message
news:hbuygam1.fsf@repairfaq.org...
I have an Extech 380652 that seems to work well in general but has
an approximately 0.06 A offset in the AC Amps mode on the 20 A range.

The user offset adjust pot only works on DC Amps.

Does anyone know if any of the 3 pots inside are for the AC amps offset?

Thanks!

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Click to expand...

Not just extraneous pickup from building wiring maybe ? Probably not, but
just a thought ...

Arfa
 
S

Samuel M. Goldwasser

Guest
I have an Extech 380652 that seems to work well in general but has
an approximately 0.06 A offset in the AC Amps mode on the 20 A range.

The user offset adjust pot only works on DC Amps.

Does anyone know if any of the 3 pots inside are for the AC amps offset?

Thanks!

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
On Sat, 19 Sep 2009 17:55:58 +0100, "Arfa Daily"
<arfa.daily@ntlworld.com>wrote:

"Samuel M. Goldwasser" <sam@repairfaq.org> wrote in message
news:hbuygam1.fsf@repairfaq.org...
I have an Extech 380652 that seems to work well in general but has
an approximately 0.06 A offset in the AC Amps mode on the 20 A range.

The user offset adjust pot only works on DC Amps.

Does anyone know if any of the 3 pots inside are for the AC amps offset?

Thanks!

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/


Not just extraneous pickup from building wiring maybe ? Probably not, but
just a thought ...

Arfa
Click to expand...
Don't know if this is relevant but my original Amp Clamp will have an
offset if the two ends that clamp together aren't perfectly clean.
 
"Dave Plowman (News)" <dave@davenoise.co.uk> writes:

In article <hbuygam1.fsf@repairfaq.org>,
Samuel M. Goldwasser <sam@repairfaq.org> wrote:
I have an Extech 380652 that seems to work well in general but has
an approximately 0.06 A offset in the AC Amps mode on the 20 A range.

The user offset adjust pot only works on DC Amps.

Does anyone know if any of the 3 pots inside are for the AC amps offset?

0.3% of FSD error? Isn't that quite good for this sort of device? One I
have is quoted at +/-2%. Of course with a constant error there's always
the temptation to sort it out.
Click to expand...
If it were the clamp-on DC range, it would be good. But the AC clamp-on
is just a transformer secondary. It SHOULD read 0 with nothing there! :)

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
In article <8wgafo0f.fsf@repairfaq.org>,
Samuel M. Goldwasser <sam@repairfaq.org> wrote:
0.3% of FSD error? Isn't that quite good for this sort of device? One I
have is quoted at +/-2%. Of course with a constant error there's always
the temptation to sort it out.

If it were the clamp-on DC range, it would be good. But the AC clamp-on
is just a transformer secondary. It SHOULD read 0 with nothing there! :)
Click to expand...
If it were just a plain winding that might be so. But it has to open to
allow fitting round a cable.

--
*INDECISION is the key to FLEXIBILITY *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
"Dave Plowman (News)" <dave@davenoise.co.uk> writes:

In article <8wgafo0f.fsf@repairfaq.org>,
Samuel M. Goldwasser <sam@repairfaq.org> wrote:
0.3% of FSD error? Isn't that quite good for this sort of device? One I
have is quoted at +/-2%. Of course with a constant error there's always
the temptation to sort it out.

If it were the clamp-on DC range, it would be good. But the AC clamp-on
is just a transformer secondary. It SHOULD read 0 with nothing there! :)

If it were just a plain winding that might be so. But it has to open to
allow fitting round a cable.
Click to expand...
Same offest open or closed. This meter is in mint condition, no visible
damage anywhere.

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
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