I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the left.
Any solutions to return it to it's normal state. I tried reverse polarity-
it goes to the left, but then returns to center.

thanks

"Mike Muderick" wrote in message
news:%zZLf.1774$%v4.565@trnddc03...
I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the
left.
Any solutions to return it to it's normal state. I tried reverse
polarity-
it goes to the left, but then returns to center.

thanks
Just wondering--is there a zero-adjust screw or tang (for want of a better
word) on the meter?

HankG

The meter is magnetized and now sits center scale,

Cobblers and rubbish. You've probably dropped it.

Like Hank suggested, should be a flathead screw adjustment on the front of
the meter, at the bottom.

"Mike Muderick" wrote in message
news:%zZLf.1774$%v4.565@trnddc03...
I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the
left.
Any solutions to return it to it's normal state. I tried reverse
polarity-
it goes to the left, but then returns to center.

thanks

"Mike Muderick" wrote in message
news:%zZLf.1774$%v4.565@trnddc03...
I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the
left.
Any solutions to return it to it's normal state. I tried reverse
polarity-
it goes to the left, but then returns to center.

thanks



Sounds more like some kind of mechanical failure, I've never heard of
magnetism causing that margin of error.

Dave

Mike Muderick schrieb:

I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the left.
Any solutions to return it to it's normal state. I tried reverse polarity-
it goes to the left, but then returns to center.

I've seen such an effect when the transparent plastic cover of the scale
has
been wiped intensively for cleaning purposes generating electrostatic
charge.
Try to breathe on the plastik to discharge it.

HTH

Reinhard

"Dave D" writes:

"Mike Muderick" wrote in message
news:%zZLf.1774$%v4.565@trnddc03...
I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the
left.
Any solutions to return it to it's normal state. I tried reverse
polarity-
it goes to the left, but then returns to center.

thanks

Sounds more like some kind of mechanical failure, I've never heard of
magnetism causing that margin of error.

Magentism won't affect a normal D'Arsonval meter movement as far as
zero position is concerned.

If you examine it closely, there will probably be an obvious cause like
a bent needle or misadjusted zero screw.

--- 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.

Tried all of the above. There is no zero-adjust screw. Took the plastic
cover off to try and discharge any static electicity. Nothing is bent-
meter wasn't dropped- It just won't go back to zero.
mm


"Reinhard Zwirner" wrote in message
...
Mike Muderick schrieb:

I have a battery tester meter (Mallory) that came from a retail store.
The
meter is magnetized and now sits center scale, instead of over to the
left.
Any solutions to return it to it's normal state. I tried reverse
polarity-
it goes to the left, but then returns to center.

I've seen such an effect when the transparent plastic cover of the scale
has
been wiped intensively for cleaning purposes generating electrostatic
charge.
Try to breathe on the plastik to discharge it.

HTH

Reinhard

Mike Muderick wrote:
Tried all of the above. There is no zero-adjust screw. Took the
plastic cover off to try and discharge any static electicity.
Nothing is bent- meter wasn't dropped- It just won't go back to zero.
mm


"Reinhard Zwirner" wrote in message
...
Mike Muderick schrieb:

I have a battery tester meter (Mallory) that came from a retail
store. The meter is magnetized and now sits center scale, instead
of over to the left. Any solutions to return it to it's normal
state. I tried reverse polarity- it goes to the left, but then
returns to center.

I've seen such an effect when the transparent plastic cover of the
scale has
been wiped intensively for cleaning purposes generating electrostatic
charge.
Try to breathe on the plastik to discharge it.

HTH

Reinhard


Maybe the internal magnet shifted.

Mark Z.

Mike Muderick wrote:
Tried all of the above. There is no zero-adjust screw. Took the plastic
cover off to try and discharge any static electicity. Nothing is bent-
meter wasn't dropped- It just won't go back to zero.
mm

Hi...

It's just a shot in the dark, but doesn't cost anything so perhaps
worth a try... ?

Dampen a clean cloth in a bit of diluted fabric softener; wipe the
whole thing down with it. See what happens.

Ken

"Mark D. Zacharias" writes:

Mike Muderick wrote:
Tried all of the above. There is no zero-adjust screw. Took the
plastic cover off to try and discharge any static electicity.
Nothing is bent- meter wasn't dropped- It just won't go back to zero.
mm


"Reinhard Zwirner" wrote in message
...
Mike Muderick schrieb:

I have a battery tester meter (Mallory) that came from a retail
store. The meter is magnetized and now sits center scale, instead
of over to the left. Any solutions to return it to it's normal
state. I tried reverse polarity- it goes to the left, but then
returns to center.

I've seen such an effect when the transparent plastic cover of the
scale has
been wiped intensively for cleaning purposes generating electrostatic
charge.
Try to breathe on the plastik to discharge it.

HTH

Reinhard


Maybe the internal magnet shifted.

Mark Z.

Huh?

--- 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.

Well, since you've already had the cover off, try this.
Open the meter again and gently try to move the needle back toward zero with a
fingertip or a toothpick. If it doesn't move freely, or moves but stays in the
position it was moved to, your meter is damaged. Most likely cause is a broken
hairspring or pivot. In either case, the meter is unrepairable by most. The
only course of action is to buy a new tester.
You can, of course, get some small tools and gingerly disassemble the meter to
get at the innards, but if the meter is damaged as I described, you're just
chasing a rainbow.

If the meter needle does move freely but just returns to mid scale, you might be
able to remedy that. Open the meter and remove the screws that hold the meter's
mechanism in the housing. You might have to fiddle with the wires that connect
the meter mechanism to the terminals on the rear of the housing. Keep them out
of the way, or at least keep the strain off those wires because they attach to a
delicate mechanism. On the rear of the movement is another pivot adjustment,
normally where one of the connecting wires is soldered. Gently move this pivot
arm and see if the needle responds. If so, see if there is enough range in
movement to return the needle to normal zero position. If so, you're home free.
If not, you're back to square one, looking for a new tester.


--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Never take a laxative and a sleeping pill at the same time!!
"Mike Muderick" wrote in message
news:KW2Mf.5967$pE4.4446@trnddc04...
Tried all of the above. There is no zero-adjust screw. Took the plastic
cover off to try and discharge any static electicity. Nothing is bent-
meter wasn't dropped- It just won't go back to zero.
mm


"Reinhard Zwirner" wrote in message
...
Mike Muderick schrieb:

I have a battery tester meter (Mallory) that came from a retail store.
The
meter is magnetized and now sits center scale, instead of over to the
left.
Any solutions to return it to it's normal state. I tried reverse
polarity-
it goes to the left, but then returns to center.

I've seen such an effect when the transparent plastic cover of the scale
has
been wiped intensively for cleaning purposes generating electrostatic
charge.
Try to breathe on the plastik to discharge it.

HTH

Reinhard

DaveM wrote:

Well, since you've already had the cover off, try this.
Open the meter again and gently try to move the needle back toward zero with a
fingertip or a toothpick. If it doesn't move freely, or moves but stays in the
position it was moved to, your meter is damaged. Most likely cause is a broken
hairspring or pivot. In either case, the meter is unrepairable by most. The
only course of action is to buy a new tester.
You can, of course, get some small tools and gingerly disassemble the meter to
get at the innards, but if the meter is damaged as I described, you're just
chasing a rainbow.

If the meter needle does move freely but just returns to mid scale, you might be
able to remedy that. Open the meter and remove the screws that hold the meter's
mechanism in the housing. You might have to fiddle with the wires that connect
the meter mechanism to the terminals on the rear of the housing. Keep them out
of the way, or at least keep the strain off those wires because they attach to a
delicate mechanism. On the rear of the movement is another pivot adjustment,
normally where one of the connecting wires is soldered. Gently move this pivot
arm and see if the needle responds. If so, see if there is enough range in
movement to return the needle to normal zero position. If so, you're home free.
If not, you're back to square one, looking for a new tester.




Before you change the rear spring setting you should inspect the spiral
springs. I have seen cases
where the spiral turns got tangled (probably by too much current). I
used a tooth pick or small
wire to untangle the loops of the spring. Also look at the pivots. If
your meter coil and pointer
are supported by a "taught band" then all of the advice I gave doesn't
apply.

Bill K7NOM

"Sam Goldwasser" wrote in message
...
"Mark D. Zacharias" writes:

Mike Muderick wrote:
Tried all of the above. There is no zero-adjust screw. Took the
plastic cover off to try and discharge any static electicity.
Nothing is bent- meter wasn't dropped- It just won't go back to zero.
mm


"Reinhard Zwirner" wrote in message
...
Mike Muderick schrieb:

I have a battery tester meter (Mallory) that came from a retail
store. The meter is magnetized and now sits center scale, instead
of over to the left. Any solutions to return it to it's normal
state. I tried reverse polarity- it goes to the left, but then
returns to center.

I've seen such an effect when the transparent plastic cover of the
scale has
been wiped intensively for cleaning purposes generating electrostatic
charge.
Try to breathe on the plastik to discharge it.

HTH

Reinhard


Maybe the internal magnet shifted.

Mark Z.

Huh?

--- sam | Sci.Electronics.Repair FAQ:

Well, the coil has to react with something. It's been a long time since I've
taken a meter movement apart, but clearly at the heart of the meter movement
is a magnet. If the magnet is normally stationary, while the meter coil and
pointer move with voltage applied, if the magnet were to physically rotate,
this would affect the zero center of the coil / pointer, yes?

Mark Z.

"Mark D. Zacharias" wrote in message
om...

"Sam Goldwasser" wrote in message
...
"Mark D. Zacharias" writes:

Mike Muderick wrote:
Tried all of the above. There is no zero-adjust screw. Took the
plastic cover off to try and discharge any static electicity.
Nothing is bent- meter wasn't dropped- It just won't go back to zero.
mm


"Reinhard Zwirner" wrote in message
...
Mike Muderick schrieb:

I have a battery tester meter (Mallory) that came from a retail
store. The meter is magnetized and now sits center scale, instead
of over to the left. Any solutions to return it to it's normal
state. I tried reverse polarity- it goes to the left, but then
returns to center.

I've seen such an effect when the transparent plastic cover of the
scale has
been wiped intensively for cleaning purposes generating electrostatic
charge.
Try to breathe on the plastik to discharge it.

HTH

Reinhard


Maybe the internal magnet shifted.

Mark Z.

Huh?

--- sam | Sci.Electronics.Repair FAQ:

Well, the coil has to react with something. It's been a long time since
I've taken a meter movement apart, but clearly at the heart of the meter
movement is a magnet. If the magnet is normally stationary, while the
meter coil and pointer move with voltage applied, if the magnet were to
physically rotate, this would affect the zero center of the coil /
pointer, yes?

Mark Z.


Actually, just realized my error. If the coil were magnetized, my point
might have been valid, otherwise not.

"never mind"


Mark Z.

"Mark D. Zacharias" writes:

"Mark D. Zacharias" wrote in message
om...

"Sam Goldwasser" wrote in message
...
"Mark D. Zacharias" writes:

Mike Muderick wrote:
Tried all of the above. There is no zero-adjust screw. Took the
plastic cover off to try and discharge any static electicity.
Nothing is bent- meter wasn't dropped- It just won't go back to zero.
mm


"Reinhard Zwirner" wrote in message
...
Mike Muderick schrieb:

I have a battery tester meter (Mallory) that came from a retail
store. The meter is magnetized and now sits center scale, instead
of over to the left. Any solutions to return it to it's normal
state. I tried reverse polarity- it goes to the left, but then
returns to center.

I've seen such an effect when the transparent plastic cover of the
scale has
been wiped intensively for cleaning purposes generating electrostatic
charge.
Try to breathe on the plastik to discharge it.

HTH

Reinhard


Maybe the internal magnet shifted.

Mark Z.

Huh?

--- sam | Sci.Electronics.Repair FAQ:

Well, the coil has to react with something. It's been a long time since
I've taken a meter movement apart, but clearly at the heart of the meter
movement is a magnet. If the magnet is normally stationary, while the
meter coil and pointer move with voltage applied, if the magnet were to
physically rotate, this would affect the zero center of the coil /
pointer, yes?

Mark Z.


Actually, just realized my error. If the coil were magnetized, my point
might have been valid, otherwise not.

"never mind"

Right.

--- 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.

Mike

a ½ scale thing like this is usually a hair spring failure or possible
a shock to the spring has caused a coil to interfere with another.
Bob AZ

Mike

a ½ scale thing like this is usually a hair spring failure or possible
a shock to the spring has caused a coil to interfere with another.
Bob AZ

Bob AZ wrote:
Mike

a ? scale thing like this is usually a hair spring failure or possible
a shock to the spring has caused a coil to interfere with another.
Bob AZ

I think you might find that these Mallory cheapo testers actually
place a load across the cell under test. The meter may not be a
hair spring device at all but more like a car Amp meter.

Chances are good that the meter movement has suffered physical damage,
or has had a mechanical part failure.

Damage can be related to harsh handling or misuse. Checking a battery
voltage that exceeds the selected range/type can cause irrepairable
damage. In many cases, this will open the moving coil windings (fuse
action).

I suspect that since the meter will deflect down-scale (as well as up),
that the problem is a damaged hairspring. There are almost always 2
hairsprings, which are wound in different directions, at each end of
the armature.
As each hairspring tension opposes the other, if one were removed or
weakened, the other would be stronger, moving the pointer "harder" in
that direction.

If the meter movement isn't the moving coil type, then a hairspring or
the band has possibly been damaged (weakened or distorted) by
overvoltage or misuse.

If the meter wouldn't deflect down-scale, I'd suggest that the problem
might be a small bit of debris inside the meter movement that was
stopping the coil from returning to it's zero position. Sometimes a
small magnet flake or other material will cause this.

Resetting hairsprings is (not can be) a very delicate procedure. Meter
manufacturers used to actually list hairsprings as replacment parts.
The tension needs to be precisely balanced for a precision meter
application. Many armatures also utilize counterweights fitted on pins
that extend outward radially.

If it's a separate panel meter (not built into the tester's case), and
you can see some numbers on the meter, you may be able to find a
suitable replacement meter assembly. Many meter movements have a full
scale current value printed on the meter faceplate/scale plate,
something similar to 100uA DC F.S. (full scale deflection at 100
microamps).
For using meters of different ratings as substitute replacements, refer
to books covering meter shunt resistors and similar topics.

Cheers
WB
.................

Mike Muderick wrote:
I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the left.
Any solutions to return it to it's normal state. I tried reverse polarity-
it goes to the left, but then returns to center.

thanks

On Sat, 25 Feb 2006 14:11:07 GMT, "Mike Muderick"
wrote:

I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the left.
Any solutions to return it to it's normal state. I tried reverse polarity-
it goes to the left, but then returns to center.

thanks


Hi There, Lets not discount the fact that there may be a small piece
of metal shaving that has worked its way into the center of the magnet
and is lightly brushing the coil assembly, making it stick. This is
more common than you think. a Simpson "S" meter on a Collins Amateur
Receiver I own had this problem. What really suprised me that the
Simpson meter had never been taken apart before, so this was a factory
included screwup!! After some head scratching, and finally taking the
meter out and the movement apart, and unbolting the two screws that
hold the coil assembly in, I was able to "wipe" the little piece of
metal out of the magnetic hole. I reasembled the unit, and its working
fine to this day.... Oh, BTW, since this is a battery test meter, I
highly doubt that the movement would be a "taut band type" as these
are mostly used on high $$$ wattmeters and bench test multimeters that
don't get bumped around alot. One more final thought.. You may have
had one of the balance wires fall off, and may be sitting in the
bottom of the meter. This item will look like a tiny wrapped coil, and
goes on one of the two prongs near the center of the movement..
Sometimes the parafin used to hold these non ferrous balance weights
fall off, also causing a meter to do what you have said.. Best Luck!
Anthony, WB8MLA

In article %zZLf.1774$%v4.565@trnddc03, "Mike Muderick"
wrote:

I have a battery tester meter (Mallory) that came from a retail store. The
meter is magnetized and now sits center scale, instead of over to the left.
Any solutions to return it to it's normal state. I tried reverse polarity-
it goes to the left, but then returns to center.

Mike-

It is not magnetized. Since you have shown that static electricity is not
causing it, there are two other causes I can think of.

1. It is a zero-center meter movement that is biased to one end of the
scale when turned on and working.

2. There are coil springs at both top and bottom of the meter shaft.
These springs oppose each other. One of them is broken.

Fred