frequency recorder

benoit · Post by **benoit** » Wed Sep 15, 2004 9:34 am

You answerd my question on frequency recording in picolog (Mon 9 Aug 2004) and I can now measure frequency with picolog.

However, the accuracy is not good enough with my adc200/20.
I would need to set the scan time at 25000000 us to get the right frequency range (0-33Hz) (i need to measure a 25Hz signal) but with a scan time uper than 10000000 us (range 0-67Hz) , the frequency reading become eratic.

How i can fix this without changing of hardware ?

Thanks.

Benoit

bthieb@mnhn.fr

Sarah · Post by **Sarah** » Thu Sep 16, 2004 1:48 pm

Hi Benoit

Thank you for your post.

In order to measure the low frequencies that you are looking at, I would recommend using a frequency to voltage converter. Picolog is not optimal for measuring frequencies, particularly those of such a low magnitude.

If you use a frequency to voltage converter then your ADC-200 will be able to measure this much more accurately and then you can convert the voltage back to a frequency in the software by using scaling.

Hope this helps

Best Regards