I gotcha I've also experienced how hard it is to tell the absolute truth when so many exceptions roam around.
I'll still use my Hanna. It's all there is available for a decent price. I just won't take it or tout it as Gospel. Labs have been pretty much like that so far too with up to 25 PPM deviation from batches made the same way and metered the same by the same meter. [But, alas, not the same batch and the meter in common was a Dist 1] I think the real point in all this is that it's pointless to argue about PPM when it's entirely possible that NO ONE really knows what they have. [and it doesn't really matter that much] OK list I have an idea. I'll make a great big batch of CS, let it stabilize for a week or so, split it up and send it to several labs and see what happens. Can listers suggest labs they'd like to see compared? [that aren't extremely expensive :-)] I can post results as "lab A, using such and such a method" etc so as not to put anyone on the spot. I know that they all do the best they can with the best they have to work with. I'll try to get some run through the "major pharmeceutical research lab" too. [not a lot of red tape hope for that, but I'll ask] I think I can sneak another sample through the state water lab. [It only does work for gov't agencies and it's HUGE!] If people who have a PWT meter want to participate, send me your address and I'll send you a portion. [One per country other than USA?] Of course, if you happen to have a lab AND a PWT, well, two birds with one shipping charge? Curious but far from rich [Freebies and donations accepted but not expected] Ken At 10:57 PM 10/29/02 +1300, you wrote: >No worries Ken, they get us all every so often. > >I do agree with your sentiment for sure, I believe the way advertising >is used is evil, and has its hand in the social and moral decline of >our western civilization. > >Mate, I think turntables and valves sound best. > >Returning to measurement error and your ruler example. > >Yes the ruler is the same the entire range, start to finish, but >imagine that we have viewing system that can zoom in and out, but only >allows us to see 100 marks at a time +/- 2 marks. We zoom in so that >we can see 100mm of this ruler, this is the 100mm scale ;-), we can >see all the millimetre marks +/- 2 so our error is 2% of the full >scale reading. Now we zoom out so that we can see 1 metre of the >ruler, the metre scale. The 100 marks we can see (+/- 2) are >centimetres and so our error then becomes +/- 2 cm which is also 2% of >the full scale reading. Digital equipment works this way because one, >there is a limited number of display digits, and two because they use >limited digital to analogue converters which split the thing being >measured into a finite number of bits. Your digital multimeter works >this way. The error of an analogue meter with a swept gauge has a >similar error, but this arises from the inability to print fine enough >marks on the face as the scale gets larger and the ability to read >them accurately. A ruler has the same problem, it measures an infinite >number of points most of which we can't see. > >Hopefully you will think a little better of your Hanna meter. > >in error >Ivan. > >> -----Original Message----- >> From: Ode Coyote [mailto:[email protected]] >> Sent: Tuesday, 29 October 2002 6:59 a.m. >> To: *Silver-List* >> Subject: RE: CS>TDS/PWT meters >> >> >> Sorry Ivan >> Strange mood and recent encounters with lawyer mentalities >> in consumer >> industry. [Ripped off by ommissive merchandising] >> It's not me fighting you, it's commentary about how truth >> can be more >> legal than true. >> Last shot at making the point, I promise. >> >> If you ever gone out and shopped for an amplifier, you >> won't trust the >> specs to be clear. Peak power doesn't mean the amp will >> sound good a over >> half volume and so on, but using a peak power rating makes >> the product look >> good...THEN you may or may not find the fine print at the >> end of the manual. >> Nearly everyone tries to make their product look as good as they can >> without actually lying. Confusion is often deliberately >> promoted even in >> the biggest and best. >> Microsoft never just comes out and says your system might >> hang or crash >> now and then. ATI doesn't tell you your expensive video >> card might make >> the entire system totally unstable. They leave that for >> you to find out. >> Samsung proudly advertizes on one of its DVD players a "full screen >> button" that gets rid of those midgets and black lines,[Oh >> look Marge! Now >> we can watch the same sized TV we bought!] but fails to >> mention anywhere >> that the button makes everyone look like Barney Fief [Tall >> and skinny]. OHH >> Kaaayy, it does what it says it does but you still can't >> watch it without >> going insane. [Legally true but not truthful to the buyers >> obvious intent >> and purpose of the function] >> Now these are major companies with , uh, ethics..right? >> >> When Hanna failed to mention that the full scale at 999.9 >> was not the same >> as the operational range of 99.9, I lost quite a bit of >> faith in them. How >> does one attach a value to something without mentioning >> what that something >> is despite its obvious importance to qualifying the value? >> If you have a one foot ruler with an accurate range within >> the first inch, >> the full scale is one foot no matter how fuzzy the lines >> are after one >> inch. If then, you state that accuracy is related to the >> whole ruler, what >> leads one to assume that the first inch is any different >> than the whole >> ruler? Is it the fact that they failed to tell you how >> long the ruler >> was...implying that it was only an inch long, by ommission? >> >> When I discovered 'all on my own' that my ruler was ten >> times longer than >> they implied it was and clearly attached accuracy to the >> whole thing...not >> just the first inch, it left a lot of questions about how >> well it works >> when attaching accuracy to the range rather than the scale >> would have made >> it very clear. >> "Reads accurately within +/- 2% in an operational range of >> 99.9 uS with a >> full scale of 999.9 uS" What's so hard about that? One >> lousy sentence says >> it all and places truth beyond reproach. >> The way they DID state it says "lawyer" all over it. >> Lawyer means 'who >> gets away with what', never mind the truth. The two 'could' >> be the same but >> don't have to be and the 'system' implies that it always is. [but >> experience says otherwise] >> Why do you suppose laywers and the system have their own >> language? It's >> certainly not about communicating with clients. Note any >> similarity between >> that and merchandising? >> Were these small hand held meters designed for scientists? >> >> Does 'this' meter have more than one scale? [ I don't see >> any mention of >> more than one scale OR how big the scale is.] >> If the instrument does have more than one scale and the >> specs are not the >> same throughout, each scale needs a different spec...or at >> least some >> mention that there may be differences..or no specs at all. >> Were the specs written for 'this' meter or not? >> >> Ken >> > > >-- >The silver-list is a moderated forum for discussion of colloidal silver. > >Instructions for unsubscribing may be found at: http://silverlist.org > >To post, address your message to: [email protected] > >Silver-list archive: http://escribe.com/health/thesilverlist/index.html > >List maintainer: Mike Devour <[email protected]> > >
