Hand held TDS meter options
 

I currently have an HM Digital TDS-3 meter and I despise it. It is horrible to try to calibrate with the screwdriver that you move a billionth of a mm and the meter goes up by 50 ppm. The Hanna TDS-1 uses the same type of screwdriver calibration. I'm looking for something easier to calibrate.

The only hand held TDS meter that I know of that doesn't use a screwdriver for calibration is the HM Digital COM-100 meter. It is also top of the line, and rather pricey.

Anyone know of any other TDS meter that doesn't use that stupid screwdriver calibration?

EDIT: Just found the Hanna HI 98311 Waterproof Low Range meter self calibrates like their pH meters. Excellent! However, just as pricey as the HM Digital COM-100 meter! :lol:

EDIT 2: The Hanna Primo has automatic calibration with 1382 ppm fluid. It suggests 2% +/- accuracy, but I wonder how accurate it is when it is very close to 0? I will send email. This meter is only $20.

Walmart in the rv isle, costs 10 or 15 bucks if memory serves me correctly.

How is it calibrated?

The Walmart one does not have a calibration, turn it on stick it in the water and you get a reading.

Hmmm...I don't like that idea.

You hold the button till it reads zero, then put it in your water. Not entirely sure why calibration is necessary on some these. Out of liquid it should always read 0. The walmart one works good enough for our needs, filter replacement.

Mine has read 15 ppm off when I have calibrated it. It always says 0 out of liquid. I want to change my filters when I get 1 ppm tds, not 15 ppm! Mostly I'm just sick of my particular TDS meter, and I'm looking for something different, but no I don't want to spend $80 on a tds meter! Just looking at other options.

I have a Hanna Primo I will be posting Mindy.
Bought in 2007, used a couple times. Never did open the cal fluid pouch. :redface:
Pretty much mint condition, cept the batteries are dead. I'll check and see if I have some spare batteries kicking around tonight.

http://www.members.shaw.ca/ryan.muis...f/DSC_0632.jpg

Excellent. Maybe I can nab it off ya when I come to Edmonton next. :)

I just have a cheapo hand held as well and haven't bothered with calibration. My RODI system has the standard dual TDS meter and I've never cal'd that one either. One time I pulled a probe from the dual TDS job and compared the reading to the handheld, difference was about 10-15 ppm when reading my tapwater. If memory serves, the handheld read lower. My tap is around 210 with the handheld and 220 with the dual TDS probe. I think I tried both the dual TDS probes and they were both reading the same. That's the one I'm more concerned about, not the handheld, since the dual TDS is on my RODI. I'm pretty ok with trusting the dual to tell me when the TDS out of the DI stage starts to creep above 0. I'm kind of with Binare on this one, for our purposes do we really need to be tweaking these things for a few tens of ppm? Of course if I had access to a more accurate/pricey instrument, I'd certainly give it a go to compare.

Exactly, a lot of stuff geared towards this hobby is pure fluff and waaay overpriced. IMO if it reads 0 in bottled water, it works good enough to judge when to change my filters. Mine gets used every 6 months or so, when the season changes. I tested mine a month ago, 2ppm, change out media, double check with the wifes bottled water, reads 0ppm. End of story, back in the drawer till march or so.

If the meter is out the other direction it won't say -10ppm in the bottled water, but it will still test your RO water at -10ppm of whatever it is, so your RO water could be 9ppm and the meter will still read 0ppm. That's one of the reasons why you need to use calibration fluid not distilled water.

Of these meters that you can't calibrate, I would like to see what they read when someone puts them into 342ppm calibration solution just to see how far off they really are. I just don't see the purpose of using something to test when the tester itself isn't accurate. That makes no sense at all to me. :lol:

To each there own. I bought this years ago on Kevin at RCs recommendation to save a few bucks. But I will say, these are quite simple, Its a simple measure of conductivity, that's it. I highly doubt a bottle of distilled water or new filters and media will read 10ppm, in fact if it did, I'd just use that as my baseline instead of 0, its not a ph probe. Just offering something up that costs a lil less is all.

Then don't use it ;) I personally couldnt care if it read 342 at 342. As long it reads a difference between 0 and something, something is too much and ill change the filters. If it said on/off, yes/no, crap in your water/water is clean, that would be good enough

I guess it is to each their own. I find more value in my TDS meter than my pH meter. :lol: I understand there are lots of cheap meters out there, I have one already. I'm looking for a reasonably priced meter with a specific option - that being automatic or push button calibration instead of screwdriver calibration. Thanks for offering up your suggestions though. All suggestions are always appreciated.

Hey Myka,

I have a HM Digital dual meter on my RO system. You can't calibrate, and I never thought about it. But now I am wondering what it really is, so at least I know. What calibration liquid would you recommend?

I just changed my filters 2-3 weeks ago, and it is reading 0ppm, but as you stated, is it really that. You got me curious. As my filters are new, I am not worried, just curious.

I use the HM Digital 342 ppm sodium chloride solution. Any brand will work, but I find the 342 ppm to be the most suitable for our use. You want to pick something close to the ppm you will be testing.