Hi! What should I use for our project about earthquake alarm? Which is better, tilt sensor or vibration sensor? Thanks!
By the time the building is tilting, isn't it a bit too late?
(A tilt sensor and a vibration sensor may well be based on the same device - an accelerometer)
your question is like what color is better ?
if you put a simple scale in the baseent and it goes from 0 to the weight of the house, you know the house fell from the earthquake. simple yes or no output.
if you have a spring type sensor, it will shake from movement but only complete the signal once the harmonics of the vibration match that of the spring OR the signal overwhelms the device.
think a singer who can break a glass or a hammer. either way the glass breaks, but the cause is completely different.
if you want to create a plot of how much the earth is shaking, you need something other than a spring with a contact.
it boils down to APPLICATION.
that said, please give us more details and we can better offer an answer that will be of any use.