[Phys-L] Re: Lab DMM Recommendations?

[James Mackey <jmackey@HARDING.EDU>]

Robert Cohen wrote:

> I was thinking the same thing almost.  Does anyone require students to
> buy a meter (from the bookstore, for example) BEFORE coming to lab?  The
> really cheap ones (<$10) aren't too much of a strain on students'
> budgets and students will be more careful about fuses and connections if
> breaking one means they have to buy another.
>
> This would also decrease the diffusion coefficient (or rate at which
> meters diffuse out of the room...).
>
> ____________________________________________________
> Robert Cohen; 570-422-3428; www.esu.edu/~bbq
> East Stroudsburg University; E. Stroudsburg, PA 18301
>
>
>
>
> > -----Original Message-----
> > From: Forum for Physics Educators
> > [mailto:PHYS-L@list1.ucc.nau.edu] On Behalf Of Bernard Cleyet
> > Sent: Friday, February 18, 2005 1:06 AM
> >
> > Just occurred to me the soln. (assuming the cheapie will do)
> > is to give
> > each student one of them (you have a lab fee, no?);   if one destroys
> > it, one buys the replacement.
While several have spoken against the cheapo meters, I have a different
viewpoint.  All of the DMMs I have bought are inexpensive (<$30), most
of them have had temperature capability, all have had a 10 amp scale,
and many have capacitance measurement also.  While these do get
occasionally fried (most common is connecting the Volt function as a
current meter) it has normally required only the replacement  of a
fuse.  When they do die, they are simply thrown away and another similar
one purchased.  If we used expensive meters (E.g. Fluke $100 ones) I
woudl be much more concerned about student use of the meters.  In my
view they are expendable lab supplies, like silver pens for electric
field plotting. etc.
James Mackey