According to Jeff Wisnia :

Testing fuses is sort of like testing firecrackers isn't it? The good
ones are rendered unusable if they "pass". G

Depends on what the test is.

a) Does it pass the full rated current for the specified time?

(This one would leave a fully functional fuse if it passed.)

b) Does it blow within the specified time for a specified
overcurrent?

(Here, of course, those which passed would be useless. :-)

Course I suppose if you have knowledge of the resistance versus current
characteristics of a "good" fuse of the same alloy and design, you could
put some current through them and see if what you've got matches
reasonably closely.

A reasonable approach.

When I got the recall notice I thought for a moment about grabbing my
magnifying optical comparitor and looking to see if the links in those
fuses stepped up in size sort of appropriate to their amperage ratings,
but then thought better about that, said, "WTF", and went for a nice end
of summer walk with SWMBO.

A better use of your time, I think. :-)

Let's hear what your examination and tests show, my suspicion is that
someone probably mixed up the metal parts and they ended up in the wrong
fuses.

And since the markings are on the plastic caps ... :-)

Hmm ... I wonder whether there is anything stamped in the
"blades"?

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---