Re: Body water content (was: WW-is this my next step?)

[Guest guest]

> How does a scale know the

> difference between water weight

> and fat weight?

It doesn't! The scale has electrical

contacts which connect a low (about

250mV) alternating voltage at

several different frequencies (in

the range 5kHz to 200kHz) to the

feet of the person standing on it

(with bare feet, naturally).

At low frequencies, the current

flows mainly through the extra-

cellular fluid and at higher

frequencies it flows through all

body tissues.

The procedure measures the phase

shift and hence body resistance

and reactance at various frequencies

and deduces from that the ratio of

fat-free mass to fat-containing

tissue. That value, together with

information which was previously

entered about height, sex and age of

the person being measured, is used

to derive a measure of body fluid

and body fat as percentages of the

total weight measured by the scale.

The process is called " bioelectric

multifrequency impedance analysis "

and is widely used clinically.

The scale I bought accepts and stores

information for 4 different persons.

Like everything else you can get for

$99.99, it has its little inaccuracies

so I have to accept that from one

person to the next there is an error

but there is a very small error for

the same person from one day to the

next, which is what I am interested

in.

This measurement method has been

extensively tested in comparison

with far more expensive and accurate

methods and has been approved for

clinical use.

There are slightly more expensive

devices that also deduce total body

muscle mass from the measurements

but they didn't have one at the store

where I bought the scale and I don't

have all that much muscle to measure!

Fat and water, on the other hand, I

have plenty of!

There is plenty of information on

the Internet. Start looking with

Google and the keywords:

" bioelectric impedance analysis " and

" multifrequency " .

Regards

[Guest guest]

I've been following this thread with interest and have been hoping that

would reveal the name and model number of this scale. But he

hasn't. , I give up, what is the name and model number of this

scale so I can take a look at it?

> The scale I bought accepts and stores

> information for 4 different persons.

> Like everything else you can get for

> $99.99, it has its little inaccuracies

> so I have to accept that from one

> person to the next there is an error

> but there is a very small error for

> the same person from one day to the

> next, which is what I am interested

> in.

>

Maurer

---------------------------------------

I don't make jokes. I just watch the government and report the facts.

----Will .

[Guest guest]

I've been following this thread with interest and have been hoping that

would reveal the name and model number of this scale. But he

hasn't. , I give up, what is the name and model number of this

scale so I can take a look at it?

> The scale I bought accepts and stores

> information for 4 different persons.

> Like everything else you can get for

> $99.99, it has its little inaccuracies

> so I have to accept that from one

> person to the next there is an error

> but there is a very small error for

> the same person from one day to the

> next, which is what I am interested

> in.

>

Maurer

---------------------------------------

I don't make jokes. I just watch the government and report the facts.

----Will .

[Guest guest]

> , I give up, what is the name

> and model number of this

> scale so I can take a look at it?

Soehnle Model 636666

List price is $129.99 but Direct Guys

sell it for $99.99

http://store.directguys.com/63666.html

The big advantage of this glass-plate

type of scale is that you are not

standing barefoot on metal plates but

on a sheet of strong glass so in winter

you don't get a cold shock first thing

in the morning!

It also reads consistently even when

set on soft carpet in the bedroom -

some of the older types need to be on

a hard floor to get consistent readings.

I have no connection with the retailer

or the manufacturer and I am not pushing

this product. I assume that there are

competitive devices - it just happened

to be the prettiest one on the shelf

the day I went in the store!

Regards