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Reefer and proud of it!!!
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Discussion Starter · #1 ·
Which TDS meter is perfered for an RO/DI unit. I am planing on getting an inline one for the water coming out but i also want a portable TDS meter.

Which portable TDS meter is a nice one. I have found some that look cheep for 10 to 15 bucks and some better quality for like 50 to 60 bucks.

Any Ideas.
 

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Perfeshunal Hikk
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When looking at them, pay attention to the accuracy of them. I ordered one that got here yesterday and didn't know the accuracy (should have asked before ordering it) and it is +/- 3%. I am still not sure what that means as far as accuracy though. Statistics are a sadistic game sometimes. Might be a 16 dollar mistake on my part.
 

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Perfeshunal Hikk
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either way 3% of 1 part per million is an extremely small #:arg:
That is the part I am not sure of. Is it 3% of what it is reading or 3% off? Meaning, if it reads 3 ppm, is it +/- of that 3, or, is it +/-3% of the total reading? 3% of a million parts is 30,000 ppm. I think it is what you are saying but I am not sure.
 

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Perfeshunal Hikk
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That is the part I am not sure of. Is it 3% of what it is reading or 3% off? Meaning, if it reads 3 ppm, is it +/- of that 3, or, is it +/-3% of the total reading? 3% of a million parts is 30,000 ppm. I think it is what you are saying but I am not sure.
After really thinking about it, and figuring out what I was thinking about, even if it is 3% of total, by the time it got to the point where the 3% would make any difference, the water would be so contaminated that it wouldn't matter.
 

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Reefer and proud of it!!!
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Discussion Starter · #9 ·
well how about something like this one?

HM Digital TDS-EZ Meter

Or this one from

PureWaterClub

Or even this one

HM Digital TDS-3 meter

Any one of these claim to be good. Tell why not to get these if there really is a reason for not getting them.


I like the inline meter and i will be getting that one later, but i would like to be able to take a meter with me if for any reason i go over to a friends house that has fish tanks and would like to check their water.



In all i am going to get a portable meter just looking for a meter that is reasonable in price but still gets the job done right.
 

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In all i am going to get a portable meter just looking for a meter that is reasonable in price but still gets the job done right.
yep.

of those choices I would go for the first on you listed. HM is decent stuff, and if you look at the link I posted to spectrapure, its the same one they sell for 4 bucks less as well as shipped for free from a reputable ebayer. Sounds like a good deal to me
 

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...3% of a million parts is 30,000 ppm. I think it is what you are saying but I am not sure.
Yes, but 3% of reading of 1 part per million represents 0.00000003PPM error, you're more interested in looking at what the resolution would be for such a meter, i.e. a statement that says something to the effect of what it's minimum accurate measurement would be. If you have a balance that will measure 80 mg with a + 5% acuracy, I would hesitate to measure/weigh anything down at levels around 4mg simply because the instruments prescision only allows for an error rate of 5% at a minimum weight of 80mg. I am sure that TDS meters have similar precision statements with their documentation (I haven't looked). This does not take into account the error rate for the device, nor its prescision (repeatabiility) of meaurement.

Rather than reinvent the wheel, read the following article for clarification of this concept: http://scidiv.bcc.ctc.edu/Physics/Measure&sigfigs/B-Acc-Prec-Unc.html


HTH
 

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Perfeshunal Hikk
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Yes, but 3% of reading of 1 part per million represents 0.00000003PPM error, you're more interested in looking at what the resolution would be for such a meter, i.e. a statement that says something to the effect of what it's minimum accurate measurement would be. If you have a balance that will measure 80 mg with a + 5% acuracy, I would hesitate to measure/weigh anything down at levels around 4mg simply because the instruments prescision only allows for an error rate of 5% at a minimum weight of 80mg. I am sure that TDS meters have similar precision statements with their documentation (I haven't looked). This does not take into account the error rate for the device, nor its prescision (repeatabiility) of meaurement.

Rather than reinvent the wheel, read the following article for clarification of this concept: http://scidiv.bcc.ctc.edu/Physics/Measure&sigfigs/B-Acc-Prec-Unc.html

HTH
Thank you Tom, and yes it helped.
 
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