# RE: [SI-LIST] : RMS Definition

From: Larry Miller ([email protected])
Date: Tue May 29 2001 - 12:51:20 PDT

The formal definition is an integral, f(t), etc. Sines, squares, and
triangles are just special simple cases. The "correct" way to measure it is
with a bolometer. I think that some Fluke meters work this way, and most
microwave power meters worth their salt do.

Larry Miller

-----Original Message-----
From: Neeraj Pendse [mailto:[email protected]]
Sent: Tuesday, May 29, 2001 12:41 PM
To: Doug Brooks
Cc: [email protected]
Subject: Re: [SI-LIST] : RMS Definition

Hi Doug,

The definition of RMS value of ANY given periodic signal is that DC
voltage, which when applied to a conductor, will generate the same
temperature as the given periodic signal applied to the same conductor
for the same amount of time. In essence, it is the DC voltage that
will deliver the same amount of power as the given signal when both
are applied to the same load.

- Neeraj.

National Semiconductor Corporation
http://www.national.com

>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<

On 5/29/01, 9:33:45 AM, Doug Brooks <[email protected]> wrote regarding
[SI-LIST] : RMS Definition:

> Hi Gurus

> I am looking for the mathematical formula for RMS voltage. I seem to
> remember that it can be expressed as an integral of a squared
function. I
> can almost fake it(!) but I'd like to see the real thing! I would also
like
> to see a table of RMS values for different types of (non-sinusoidal)
> waveforms (such as triangular, saw tooth, etc.) Can anyone point me
to a
> web page where this info might exist. Or perhaps, might someone create
the
> formula in an equation editor and e-mail it to me as an attachment.

> Thanks for any help

> Doug Brooks

> ***********************************************************
> Doug Brooks' book, "Electrical Engineering for the Non-Degreed
Engineer is

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