Hi George,
I believe Ivan has modified his correction factor somewhat. Our results using
the PWT meter indicate the correction factor to apply is 1.2. In that case all
your PWT readings are well below the actual ionic reading of the CS.
Example.... if your PWT reading is 17.10 (as indicated in your first reading)
then the actual value is 20.52 and the difference in the TDS reading is 4.52.
So, there is a major difference between TDS and PWT measurements. And I guess
it's worth the extra cost to use a meter that is considerably more accurate.
The TDS is just not a very good meter for this purpose.
Trem
----- Original Message -----
From: gallen4...@aol.com
To: silver-list@eskimo.com
Sent: Sunday, November 17, 2002 2:02 PM
Subject: CS>(no subject)
I have had a Hannah TDS meter for several years, but following the
discussions about the PWF, which said generally that the PWF had greater
accuracy, I bought a PWF. I have just completed a comparison of the readings on
the two on the CS I make. For the PWF readings I used the .57 conversion
multiplier which Ivan developed.
PWF TDS DIFFERENCE
17.10 16 1.1
11.11 10 1.1
15.67 14 1.67
dw 2.1 2 .1
` 15.38 14 1.38
dw 1.2 1 .2
In an effort to ensure accuracy, at this point I calibrated the PWF
13.90 15 1.1
dw 2.4 2 .4
14.36 15 .64
11.97 10 1.97
8.89 10 1.11
I think it was Ole Bob who pointed out that accurate readings with these
meters requires repeated tests with large quantities of liquid. For the small
quantities that most of us make, the readings are only approximate. If my
comparison is valid, since the difference between the readings is so small,
never reaching 2, is it worth investing in the higher-cost PWF?
George Allen
