Sinewave justification

[rmrps]

Hi friends it is possible to conclude the waveform as pure sinewave without using cro.
what are the ways to identify the sinewave i am not having cro such kind of display system. i am generating 12v ac voltage from the circuit. multimeter says the wave form contains 12v ac and 50hz but i want to confirm the wave form as pure sinewave please tell me the methods to conclude the wave form as pure sine wave. Any ciruit is there for opearating only in sinewave or any other methods to justify the wave form as pure sinewave without seeing the wave form how to conclude please give me your suggestions thanks in advance

 

[sky_123]

Perhaps _safely_ stick it in a sound card and use some software that can show you the samples, e.g. cool edit.

 

[chuckey]

There is an instrument called an audio distortion meter. What this does is to set a level on a meter, then with a notch T filter remove the fundamental, you then measure whats left, which is primarily harmonic distortion. Perhaps you could build the T notch filter bit and use an ordinary DVM for the metering.
Frank

 

[dick_freebird]

Well, the oscillosope is a dandy tool and some newer
ones will even do FFTs (older ones, some have add-on
modules). You could declare what "close enough" is, in
terms of harmonic content, and inspect. But eyeball is
probably good enough.

Similarly at such a low data rate a sound-card or DAQ
capture and Excel plotting would be close enough to
an oscilloscope, and you could probably implement a
FFT / DFT and get at harmonics that way too.

 

[kabeer02]

I think the best way do that is by using th sound card osciloscope you can download it online.