On Tue, 7 Mar 2000, Lorick wrote:

> Someone suggested another way for me to measure the RMS of a sine wave by
> just multiplying the samples by .707 using floating point methods and
> accumulate that in just 16 bits.

For a perfect sine wave the RMS is .707 times the peak. So if you always
have a perfect sine wave this will work. This only works for the peak as
far as I know, so you'll have to find some way of determining the peak as
opposed to sampling it. If you are trying to measure the RMS value of
anything other than a near perfect signwave this will not work. This is
actually the difference between ordinary multimeters and true-RMS ones.
The ordinary ones assume a signwave input and multiply the peak by .707
while the true RMS do the calculation so they work for all types of
inputs.

Jeff