It's been nearly a year since I ran this, but as I recall the difference was in the 10-20% range.
sk
-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu [mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Bernard Cleyet
Sent: Saturday, August 25, 2007 11:39 AM
To: Forum for Physics Educators
Subject: Re: [Phys-l] heat labs?
I take the opposite tack and break the bulb and immerse the filament.
Use purified water. In the case of absorbing the vis. I suspect the
fill. is v. ~ 3kK. At that temp. < 10% of the energy is in the vis.
So, do you (S. K.) obtain a 10% difference? This is a handy method of
comparing the efficiency of halo-cycle lamps with std. ones, or even
photo' or other high power lamps w/ other various power lamps. Seems
one could obtain rather good results using a well insulated, but
transparent calorimeter (unsilvered Dewar). The continuous collection
method (e.g. Vernier) is necessary.
bc
bc, thinks India ink is a dilute carbon dag. Colloidal insoluble
anything is "impossible" to remove.