time constant measurement

[AgusGleria]

Anybody has an idea of how to measure the time constant of a process, i.e. if I have a response like this one:

I need to measure the time "Tau". I need to know if there is a way to do ir automatically

[GerdW]

Hi Agus,

you need to know the start time of your process, then you need to determine when the process has settled. Then you calc the 63%-level of the step response and determine the time when that level was reached.

It sounds rather easy to get those numbers from your graph, so you should tell us where you are stuck with your problem.

Please show what you have tried so far!