Riddle me this Batman...

[glalderman]

I have a Duel TDS meter on my RO/DI unit...I have the "in" probe connected to the output of the "RO" section and the "out" connected to the output of the "DI" section...my TDS is Zero comming out of the "RO" section but reads "2" coming out of the "DI" section...probably no more than 500 gals or so through the unit...bought new in June...could it be time for a new "DI" canister already???

Greg

 

[Kreeger1]

Could be, whats your tap water read?

 

[crazyseany]

I wouldn't think the DI would "contaminate" the water would it?

even if the DI needed replaced it should read the same as the RO

Unless the resin allows stuff to leach out of it?

 

[Kreeger1]

I've heard of di leeching stuff back after a zero pass through the ro membrane
Erik

 

[MJAnderson]

I've heard that inline meters aren't that accurate long - term(according to AZDesertRat). Do you have a hand meter to test?

 

[glalderman]

Do you have a hand meter to test?

LOL! Yeah...as soon as I get the free one in the mail that we all just ordered!

I was thinking I will just swap the probes...if the in then reads "2" and the output is now "0" then I know that one of them (or both) need to be calibrated...I will wait until the "freebie" one come in and use it...hopefully it will match at least one of the two probes readings...then I will no which one I need to calibrate!

thanks for the idea's....

Greg

 

[itZme]

The club has a TDS meter for member use. If you bring a sample to the meeting you should be able to test it there. I am not sure who is the "keeper of the meter" but I think it is the librarian.

Oh yeah, I have heard that plastic will leech solids into your water sample and skew results so if you can find a small glass container it would probably be best.

 

[sohal1025]

How would you go about calibrating an in line tds meter anyways?

 

[glalderman]

Sort of like calibrating a PH probe...you put it in a standard and see what it reads...then adjust the potentiometer to read what the standard is calibrated to…

I really need to get a standard and calibrate both probes (in/out)...not just use my handheld TDS meter when it comes in...but either way...I really can't imagine that a reading of "2" is much to be concerned about...I just thought it was wierd that my "IN" reading was lower than my final "OUT" reading...

Greg

 

[itZme]

That IS a weird thing and I'm not sure I trust the meter that says 2 after the DI. I would think with as little as 1% error rate it could easily read 2 when it should say zero. The pen style meter I have goes to 999 so 1% would be a reading of 10.

I would give it a try just swapping the lines ... then maybe borrow a meter and calibrate yours to zero if the other person's meter says zero.

 

[glalderman]

I will do just that when the handheld one that I ordered the other day comes in...

 

[crazyseany]

Greg..... you know when you get it it will read 1 or something not even close..... lol