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Re: [Phys-L] ceramic fuses

I would use exactly the fuse specified.
In addition to safety reasons, here's another reason:
The resistance of the fuse determines (in part) the resistance of the ammeter.
If the resistance changes with current as the fuse heats up, the
resistance of the ammeter will not be constant.
This problem exists even when using the proper fuse in at least one
model of Extech multimeter.
I spoke to a very nice fellow at Extech about this. He said he'd check
with engineers.
After I spoke to him twice, he stopped returning my calls.!

George M. Caplan
Senior Instructor in Physics Laboratory
Wellesley College
106 Central Street
Wellesley, MA 02481-8203

On Mon, Aug 20, 2012 at 10:38 AM, <> wrote:
I have new multi-meters with, of course, different fuses than I have in
stock. The students have already blown the fuses provided as replacement.
The meter literature specifies ceramic 1/4 amp fuses. They run $3 each
Glass fuses are cheaper. So the question - Could I get away with using
glass fuses instead of ceramic? To complicate things I am "encouraged" to
order from specific venders so even if I find a vendor with real cheap
ceramics I could not order (ebay is NOT allowed)

Don Mathieson
Tulsa Community College
Forum for Physics Educators