Re: Meauring Volts?

[Rick Tarara <rtarara@SAINTMARYS.EDU>]

Partially this is a language problem--my students don't know the difference
between 'further' and 'farther' or 'to' and 'too'.  They say 'amount of'
when they should say 'number of', etc.  However, in your case (and I see
this language as well), I don't think the problem is calling the instrument
a voltmeter.  I would suggest that they see this as just an instrument name
and NOT a 'meter to measure volts' (certainly they don't see an Ammeter as
an instrument for measuring 'ams'!).  Rather the problem is really not
understanding what they are measuring.  VOLTAGE (potential difference)
really is a tough concept and way out of their everyday experience (unlike
length, weight, time).  I suspect that if you listened to early elementary
students using rulers you would also hear 'I measured the inches'.   The way
to attack the bad language is to work on the concepts of voltage,
resistance, current, etc.   Another possible factor here is the tendency (in
the student's minds) to decouple the lab and lecture.  Those concepts
discussed in lecture are not automatically transported to the lab setting.
;-(

Rick

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Richard W. Tarara
Professor of Physics
Saint Mary's College
Notre Dame, Indiana
rtarara@saintmarys.edu
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----- Original Message -----
From: "Edmiston, Mike" <edmiston@BLUFFTON.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Friday, December 06, 2002 9:49 AM
Subject: Meauring Volts?


> I just graded some lab reports from juniors and seniors in an a
> thermodynamics class.  They had used thermocouples to measure
> temperature, and many of them wrote things like, "We used a
> microvoltmeter to measure the volts."
>
> They should know better; we've discussed this type of thing before.  And
> when I ask them whether they use a ruler to measure the centimeters or
> whether they use a ruler to measure the length they think it is pretty
> obvious as well as pretty silly.  But electricity seems different; and
> we seasoned scientists are part of the problem because we call it a
> voltmeter rather than a voltage meter or a potential-difference meter.
>
> Likewise, they used a platinum resistance thermometer and said they
> "...used a precision ohmmeter to measure the ohms."  Same problem.
>
> Not in this lab, but in others we've had the same problem with students
> saying they measured the amps.
>
> Is there any hope of changing the names of these meters to voltage
> meters, resistance meters, and current meters?
>
> Along the same lines, I try to call the general-purpose meters by the
> name "multimeter" rather than "voltmeter" even though many scientists
> (and students) call it a voltmeter.  Hence, it is doubly bad when a
> student says, "I measured the ohms with a voltmeter."
>
> Anyone else having this problem?  Anyone care?
>
> Michael D. Edmiston, Ph.D.
> Professor of Chemistry and Physics
> Bluffton College
> Bluffton, OH 45817
> (419)-358-3270
> edmiston@bluffton.edu