Bell ringing frequency

1. Dec 2, 2008

UUallace

How do I calculate the frequency of an 8.5 cm diameter bell ?
The bell is cast brass for resonance, but I intend to activate it with a buzzer so sound will last for more than a few seconds. Does the weight affect anything other than volume ? I intend to use it inverted, supported near the "top".

2. Dec 3, 2008

f95toli

You don't.
For a real bell you would need to use numericial methods to solve the equations (unless you have a VERY simple bell, i.e. something very symmetric) but even then you are not very likely to get a useful answer, partly because real bells are note made of a "perfect" material; various imperfections etc (which in turn depends on how the bell was cast) can have quite a large influence on the resonance frequency.

Is there any reason why you simply can't measure the frequency? It should be easy, all you need is a microphone connected to the sound card of a computer+some suitable software.

3. Dec 3, 2008

Staff: Mentor

Here is a description of what you have to do to http://www.rps.psu.edu/sep99/freedom.html".

"dividing the surface of the bell into a grid made of 450 squares. 'There's an equation describing the vibration of each square, and the computer can solve all the equations simultaneously,' "

Last edited by a moderator: Apr 24, 2017
4. Dec 3, 2008

UUallace

"a traditional English-bell profile "
What I need is the "dominant strike chord"

Any suggestions on "some suitable software" ?

5. Dec 3, 2008

f95toli

Well, all you need is some software that can show you the frequency spectrum of the signal from the microphone. Sigview comes to mind and you can download a free trial version.

However, you could also try something VERY simple such as AP Tuner which is a program used to tune guitars, by default it will only show you what note you are playing (i.e. A, C# etc) but if you look n the "Recording Device and Calibration" it will also show you the last detected frequency.
Or, alternatively, you could just look up what frequency e.g. C# corresponds to (chances are that a bell will be reasonably well "tuned" to a note).

6. Dec 4, 2008

LURCH

7. Dec 18, 2008

UUallace

I need piezo(?) alarms to ring my bell. I need a resonant frequencies of 392 hz and 1700 hz, 12 volts would be best. Also need a 30 minute timer.