Bernard says, "Does anyone out there have a lab using a student pot.,
std. cell, etc.? bc who still cries over a lost L & N type K"
Yes, I've kept all that stuff. I still love it. But when it comes out,
the students also want to know if I walked five miles to and from
school, uphill both ways, through knee-deep snow. To which I reply, "It
was six miles and waiste-deep snow."
The thing about the old potentiometer methods is that the whole
rationale for using them is no longer true. As a student I remember the
copious warnings not to connect the standard cell to a regular
voltmeter. Today, a 10-Mohm or better voltmeter for a few seconds does
less damage than the potentiometric method does. And a 3.5-digit meter
is probably more accurate unless the standard cells are frequently
checked for accuracy.
Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton College
Bluffton, OH 45817
(419)-358-3270
edmiston@bluffton.edu