ideas for a seismometer I wanted to build and ran across the IBLs that used a piezo
element from a $1 intruder alarm as a microphone. There was my seismometer transducer.
What a deal for a buck!
A seismometer is a sensing device that detects movement of the earth's crust. These
movements are often called earthquakes when they are large enough to be felt. Since
there are not a lot of earthquakes you can feel in Georgia, I wanted a seismometer
that could detect even very small movements ("micro-quakes?").
This seismometer detects when there is a quake. The inertia of a weight suspended at
the end of a lever arm flexes the piezo element. This flexing generates a small
electrical current. That current is fed into the microphone jack on a computer or
digital recorder. Computer software then analyzes the results.
I use the term "seismometer" for the detector and the term "seismograph" for the
combined detector plus the analyzing/recording software. Some people use the term
"geophone" for the detector as the detector is an "earth microphone". I am not a
geologist so decide for yourself what terms you want to use.
There are a number of references in the last step that may help you with the project.
This might make a good science project if you live in a seismically active area.
There is a bit of soldering involved in this project, but it is otherwise pretty
simple. The cost should be $10-$15 and the software is free.