how to convert to digital output

[izzul]

hello friends,

i need some help.
Now I am a final year student at a university. I got a project, to me it is very difficult.

how can I convert the physical signal to digital signal?
for example, from flow of water, convert to voltage output.

 

[srizbf]

for every physical quantity to measure
you must have appropriate transducer(or sensor) for it.

for example ,
measure water flow - have a flow sensor for water .
pressure - pressure sensor ...

the output of such sensors may be in analog or digital form

srizbf
10thmay2010