Hi Bob, Am I a learned dissertistisator?
Any way, what you propose is a good idea for those meters that read out in MicroSeimens (uS), for those with TDS meters one would need to find out the 'TDS' factor that is used to convert uS to ppm in the meter circuitry. Many will be 0.5 but not all, they range up 2.5 I believe. Here is the method for making a standard for my Jenco conductivity meter. Also using KCl. To read 60.0uS of KCl in water. 0.744gm KCl dilute to 1L (0.01N solution) with distilled (deionised) water. Dilute 40ml of this to 1L. Of course not many can measure 0.744 gm so we should up the weight by ten to 7.44gm and up the dilution by the same. So now it reads, Dilute 7.44gm to 1L (approx. 1L) Dilute 100ml of this to 1L (900ml) Dilute 40ml of this to 1L (960ml) = 60uS For pure NaCl to read 62uS Dilute 5.84gm to 1L (approx. 1L) Dilute 100ml of this to 1L (900ml) Dilute 50ml of this to 1L = 62uS (950ml) Suggest you have your chemist weigh out 7.44gm of KCl (potassium chloride) or 5.84gm of NaCl (sodium chloride) and put it in a slip or envelope. Make sure you have an accurate measure to 100ml at least. (10 x 100ml = 1L) if you get my drift. Remember one grain of salt in the final dilution spells disaster! Oh! by the way, most of these meters are temperature compensated. Regards Ivan. ----- Original Message ----- From: <bober...@swbell.net> To: "SILVER-LIST" <silver-list@eskimo.com> Sent: Monday, 10 April 2000 09:42 Subject: CS>nomenclature > Hi Ya'all, > > Just thought it time to steer this list back to CS and its manufacture. > > I appreciate all of the learned dissertations of the technical aspect > but the proof is in the CS, but us common folk need to have a common > language. Not like the Soviets and the USA arguing over democracy since > both were using different dictionaries. > > The point being many of the "home brewers" are using the TDS1 and the > PWT (probably most are uncalibrated to something) to measure their > products and are calling the numbers read as ppm, instead of something > more like microSeimens. > > Referring to "INSTRUMENTAL METHODS OF ANALYSIS" by Willard, Merrit, and > Dean, page 720, 7.4191 grams of KCl/Kg of DW will make a solution with a > conductance of 0.01117 @ 18 deg.C. and 0.01268 @ 25 deg.. C. > > Since potassium chloride is not readily available why not do a little > math and substitute something like Morton's table salt. It is "good > enough" for home measuring. With a little more home work for the > wizards convert the units into say 1/4 teaspoon and ounces of water. > Then increase the water content so that the people will have a 30 > microSeimens standard. > > When that happens then instead of some SWAG estimate of the > concentration of the silver ions they can speak of so many uS's at their > work temperature. The solution really is temperature sensitive. My > measurements show 1/6 uS per deg.. F. between 50 F. and 100 F. > > I recognize that this smacks of standardization, but it really is need. > > "Ole Bob" > > > -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: silver-list-requ...@eskimo.com -or- silver-digest-requ...@eskimo.com with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: silver-list@eskimo.com Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <mdev...@id.net>
