Question:
I have a student who has constructed a "light listener," an
electronic device which sees a light source via a photo-transistor and emits a
sound which is characteristic of the frequency of that light. It is a science
fair air exper. and we need something to measure the frequency (?) of the
sound emitted or some numerically measurable output. What will do this,
and how do I get one?
Replies:
There are sound frequency meters. The cheapest and easiest is a
chromatic tuner, used for tuning musical instruments. You can get one
at a music store for about $30 or so. If you want to spend real money,
check in a scientific instruments catalogue.
NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.