measuring forces and length?

[Jan Pommer]

Hello,

I want to plot an impulse: So, how do I measure a force up to 500N with
a precision of 0.1N and high time resolution?
In the same time, I want to plot the way of another component, so
exactly as above I need a sonsor with high time resolution and a way up
to 20mm in steps of at least 0.1mm.

For those two problems I am searching for the best, but still cheap,
solution.

Thanks,
Jan

 

[Hal Murray]

I want to plot an impulse: So, how do I measure a force up to 500N with
a precision of 0.1N and high time resolution?

search for load cell or strain guage. Not cheap.

You'll need an A/D. You want 1 part in 5000. That's a bit over
12 bits.

You didn't say anything about what "high" means in terms of
time resolution. Do you mean audio or radar frequencies?

At audio frequencies, you might be able to use the microphone
input on your PC. It is probably AC coupled. (that is it
can't measure very low frequencies, like a constant DC voltage.
Try it.)

In the same time, I want to plot the way of another component, so
exactly as above I need a sonsor with high time resolution and a way up
to 20mm in steps of at least 0.1mm.

There are several/many types of position sensors. 1 part in 200
should be reasonable. Some things to search for:
LVDS (a rod in two coils - you measure inductance)
a spring loaded pot with a string on it
optical ?? (they used to be used to sense disk arm position)

You might try an arm on a pot.

For those two problems I am searching for the best, but still cheap,
solution.

I doubt if you will find a cheap solution.

--
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