Hand Battery

From: DonRath@aol.com
Date: Wed Feb 12 2003 - 17:51:02 PST

Dear Louise,

The hand battery provides very little current. Some multimeters (specifically,
some inexpensive analog meters, with a pointer that moves) require more
current to
make the pointer move than the hand battery can supply. If your multimeter
has a scale labeled 200 microamps or less (this is the same as 0.2 milliamps,
or 0.2 mA), then you might be able to get a current reading. I doubt if a
whose smallest dc current range is 150 mA will register any current with the
hand battery.
Possibly you might be able to get some noticeable movement of the needle on
the smallest
voltage scale, but it's questionable how meaningful the actual value of the
reading will be.

Alternatively, you might try a digital multimeter. These
generally require much less current to operate, and should do better for you
-- relatively inexpensive versions can now be found -- sometimes even under
$10. About
three years ago I used an inexpensive digital multimeter with two kitchen
pans, and got a
noticeable current reading on the 200 microamp scale and a noticeable voltage
on the 2 volt scale.

Hope this helps.

Don Rathjen
Exploratorium Teacher Institute

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