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Players of stringed instruments always
grumble that changes in humidity affect the tuning of their
instruments - especially those with natural (gut) strings. So this
weather station will have a set of strings, chosen for their
abilities to react to humidity
and a bow which will be drawn
them when you want to know the weather. The chord played will
tell you the relative humidity.
Accompanying the "humidity chord" will be a
of percussive sound played on drums in which the tension of the
comes from the internal air pressure of the drum rather than the
tension to which the skin is tightened. Thus, the note played will
depend on the relative difference between the internal and
external air pressures - a lower note
a higher external air pressure.
speed will be communicated via a small windmill which, as it
rotates, drags a thin strip of metal around a finely ridged pole, so
that it produces a continuous drone, with a frequency proportional
the wind speed.
||Given enough acoustic weather stations and enough time it would be possible to reproduce the complete works of Shakespeare, err, Beethoven.
||How does it sense temperature ?
||//How does it sense temperature //
Measure the speed of sound.
I remember one of my EE mates at college nearly 30 years ago did a final year project of a no-moving parts weather station - even the rain gauge depth was sensed by sonar.
||[8th...] Theremin-y ways to do that...
||Even better than the old man weather station. Consisting of grouches with bad knees, the output is a chorus of groans and expletives.
||Both temperature and humidity change the string tension in an instrument, making it difficult to know what variable is changing.
||[idischler], despite many studies, it has not been definitively proven that people with bad knees actually are able to feel the difference in weather. (The alternative explanation being that the knees just hurt randomly, and they remember the times when the weather is changing, just because something salient was happening. Like the pigeons in a box)
||[Smurfs] True. You'd have to either be content with a combined metric (so, if the pitch of the note rises, understand that's either getting dryer or hotter, or both), or investigate exotic materials which respond only to humidity or temerature, but not both. This latter approach might also throw up some materials which respond non-linearly to temperature or humidity, which would allow scope for producing more diverse harmonies.
||One of my DIY electronics mags has a project for an acoustic anemometer. Four ultrasonic transducers at the cardinal points of the compass, and a microcontroller to emit bleeps and measure the travel times. Simple.