That would be right, but then no meter, be it a TDS or an EC meter will give 
accurate results.  They 'estimate'.
I would not be too concerned about ppm being accurate, it doesn't have to be 
100% accurate for 'in house' purposes.  If you want 100% accuracy for 
commercial purposes, you'll have to take some to a laboratory, but you'd better 
take several samples so you can see a bigger picture of how the results will 
vary from one sample to another dependant on many factors.
Don't pay too much attention to information vendors of machines put about 
either, remember, they ALL want people to purchase THEIR machines, hence they 
will distort, exaggerate and mislead to get those sales.  ALL those machines 
which operate using LVDC produce the same end product.  LVDC machines do not 
produce 'Colloidal Silver', they produce a 'predominantly Ionic silver 
solution'.
You want to know how good your end product is?  Use visual observation.  Stock 
standard TDS meter - double the reading will get you in the ball park with an 
'estimate'.  An EC meter will have an inbuilt compensator/calculator which will 
calculate and get you in the ball park with a better 'estimate' maybe, but they 
both work on 'estimates'.
Combine either/all of the above with colour and clarity of solution in your end 
product i.e. 
1.  Clear with perfect clarity or transparency of solution - no problems as a 
meter will give you an estimate of ppm.  Use a laser pointer to highlight 
particle content.  Varying brightness of the conical beam indicates roughly if 
you have no, a few, many or anywhere inbetween of particle content.

2.  Colour evident from clear up to golden - refer to 1.
3.  If no settlement observable over time in storage - refer to 1.
If you've ticked all the above, any particles present will be bioavailable 
within the body, besides which, those particles are stuck together encased in 
water, so what happens to those 'particles' when exposed to the many 
ingredients which make up the human body after it's ingested?  I also don't put 
any store in that stomach acid business either, millions of people around the 
world can't be wrong in the efficacy of the home produced product!  So 
something else must be going on inside the body for it to be so efficacious.
Vendors can argue the toss over particle size and their TEM images until the 
cows come home.....Irrelevant, unnecessary and meaningless for the home 
producer, if you can tick the above boxes then it's bioavailable.
I had several samples of mine lab analysed many years ago so I stand by all the 
above for the home producer.  And while I have my own opinions, there are many 
here that will give you information which may not entirely agree with mine, so 
be it <g>.
N.
From: gidonke...@gmail.com
To: silver-list@eskimo.com
Date: Wed, 4 Sep 2013 02:30:18 +0300
Subject: CS>Undetactable silver

The vendor of my CS generator claims the ppm of the CS solution is inaccurately 
measured by a TDS meter,  since the silver particles the generator produce are 
too small (around 1 nano to his claim), is that correct? RegardsGidon