How to calculate integral of a waveform?

[LW-s]

I am acquiring real time 8-bit signal from a pressure sensor through analog to digital converter and displaying the signal waveform at Labview through parallel port.

the pressure waveform i acquired is like a sine wave at 0,3 HZ and 4 Volts peak to peak. i need to calculate and display the integral of pressure waveform.

i used integal x(t).vi at my project but does not worked.

do you have any recomendation that how i can display the integral waveform of my real time pressure waveform by using Labview 6.0.

Thank you for your help.

[johnsold]

What did not work when you used the Integral VI? Did you get an error, invalid data, no data? Post a simplified version of your program (without the data acquisition parts which we won't have) with some data saved as default in a control. Someone will probably be able to determine what is happening.

Lynn

[rpursley8]

If your waveform at the output of the integration function continuously rises, then you have a DC offset in your signal that you need to subtract out before you integrate.

[053647967]

Hello.

Mr. Prusley or anybody. I have the same problem. I try to integrate sine wave and my output wave of the integration function continuously rises. I expect a cosine wave if I integrate sine wave. But I get a straight line which rises from zero up. How to subtract DC offset?

I hope you have any suggestions.

Regards

[johnsold]

The standard way to remove DC offset is to take the Mean of the dataset and subtract the Mean from the dataset.  Then integrate the difference.

You have posted replies to (at least) two very old threads.  It might be better to start a new one and mention that you have looked at these old ones.

If subtracting the Mean does not work, please post your VI along with some typical data.

Lynn

[santu6038]

how to integrate acceleration signal to convert it into velocity signal?

[abinayg]

Why there’s need to subtract the DC offset to integrate sine/cos wave??

[GerdW]

Hi abinayg,

did you ever try to integrate a biased sine wave? What is the result of that bias?

Sometimes it's much better to try something on your own to learn about the problem. (Or ask your math teacher about the basic principles of integration and derivation.)

[daveTW]

And it's very easy to experiment with these questions using LabVIEW. Take this as a starting point: