5 Stars By Rob A. on 2015-09-12
Still a useful device for determining water purity
I wanted something to test our community tap water because sometimes they detect "safe levels" of bacteria in the water and don't tell us until much later after the problem is fixed. I want to be able to make my own decisions about what is safe. Unfortunately the more I read the more I see this kind of device doesn't tell you that kind of information. Bacteria and things you can filter out using a normal charcoal water filter can't be detected by a TDS meter. Almost everything this meter detects can pass through a charcoal filter. Still a useful device for determining water purity, but just know what you're buying. This meter only tells you the total combined quantity of dissolved metals, minerals, etc. in your water. This doesn't even mean a higher number is worse in some scenarios (i.e., if something is being added to the water for conditioning or flavor). The only thing I don't understand is the first thing I did was test my tap water, which read 70 ppm. I then tested my fridge dispenser water (which is charcoal filtered) and it read 80 ppm. I repeated with new water, same results. The charcoal filter is adding stuff to the water?
I think I found my answer as to why the filtered watered I tested had a higher ppm. From ClearlyFiltered.com:
"As a by-product of our patented ionic-adsorption filtration process, the charge of water passing through the filter changes slightly. This can result in TDS readings HIGHER than the tap water itself. The TDS meters are sensitive to changes in positive (+) or negative (-) charges and a higher reading DOES NOT reflect a poor water quality. It actually indicates that the filter is working and doing it’s job to remove contaminants!
1) One of the things the a TDS meter does is measure the conductivity (positive or negative charge) of the water. Our filters use an Ionic adsorption process leaving the water with a slightly positive charge. This will cause the meters to show a higher TDS reading when in reality nothing has been added to the water. In essence, it proves that the filter is working.
2) If the filters haven’t been properly flushed before they test it, there can be some residual carbon from the filter that falls off. Our filters are made from a form of Activated Coconut Carbon and during shipping some of the carbon shakes off naturally which could result in a higher TDS reading. But the carbon we use is EPA approved and has NO Health effects whatsoever. "
4 Stars By Alice Wakefield on 1969-12-31
7 years and still works, mostly.
I've been using this, maybe twice a week on average, since Sept. 2010. It stopped reading (Celsius only) temperature a while back, and the 'hold' feature no longer functions, but TDS readings are still reliable and that's what I care about. Batteries have been changed twice, I believe.
I confess my head was turned by another meter recently, but it was actually worthless and went back to AlumiGogo. The readings would jump around for 15 seconds before it quit like clockwork. Since 15-second auto-off pretty much prevents any chance of an accurate reading, this was a friggin' *brilliant* feature. It's a shame no one mentioned it. [/sarcasm]
Okay, lesson learned, the cesspool is full of impostors. At least HM Digital won't be using another name next year, but I thought by now they would've included Fahrenheit in the pens. Come on, really? I don't think we're giving it up here, it's a good system.
On the plus side:
I don't really need the 'hold' to work, since sitting in a cup of water will hold the reading anyway. They all benefit from time in the water, but the numbers don't jump around like others I've seen. I've never gotten an unexpected or wacky reading, so it seems to be pretty accurate. Reckon I'll keep it to the end.
5 Stars By RJ2207 on 2015-05-03
!!!!!!!! An accurate and wide-range TDS meter !!!!!!
We needed a meter to measure the total dissolved salt in the tap water at home.
1. The meter comes with a case and a belt clip.
2.I tried using it on liquids with know concentrations and it gives fairly accurate readings (within +/- 5%).
Also, the range of measurement is wide and can be used to measure diluted or high concentration solutions (1 to 9990 ppm).
3. It has a builtin thermometer to measure the liquid temperature (o to 80 degree C).
One should know that it doesn't measure the biological components in the water.
Also you need to buy at least two calibration solutions. I got the following two with this meter:
1. HM Digital 1000ppm TDS Calibration Solution (http://www.amazon.com/gp/product/B001FD6WZ8/ref=cm_cr_ryp_prd_ttl_sol_3)
2. HM Digital C342 TDS and EC Calibration Solution, 342 ppm (NaCl), 90 ml Volume (http://www.amazon.com/gp/product/B001VE99X8/ref=cm_cr_ryp_prd_ttl_sol_4)
ALL IN ALL, ITS A GOOD INVESTMENT FOR HOME AS WELL AS COMMERCIAL USE !!!!!!!
5 Stars By Sigara on 2017-10-06
Choose the authentic HM version, imitations are not reliable
Initially I purchased via the Warehouse deals a used HM TDS meter. The one I received was not as described. It did not have tha HM logo nor did it have the HM splash screen when the meter started up.
This knockoff had a 4% error at 341 ppm. Other imitations just the same have errors as much as 40% at the higher concentrations as they drift over time. I realized this fake won’t work so I retried ordering a new one from AlumiGogo directly.
The new one is perfect. It is an HM version and it’s error is less than 1%. Also if I need to I can recalibrate the device as it drifts. See the picture with the text describing the screw calibration.
Choose the AlumiGogo new ones if you need the authentic version. The warehouse deals may or may not be from AlumiGogo stock as buyers maybe returning their fake versions back to the warehouse.
5 Stars By ERRL on 2016-04-07
Reverse Osmosis "10% percent change" tester
Brand Name product may be same as no-name versions but, HM Digital has been around a long long time and they have a real website, therefore I feel more comfortable using, and trust their TDS products.
I'm using it to see how much TDS is in my well-water and in reverse osmosis (RO) water. I wait as long as possible to replace my RO membrane.
At my place, the manufacturer suggests replacing the membrane "every ten years". Instead of blindly agreeing, I test the TDS. When the TDS of my RO water measures 10% of my well water, then, I replace the membrane.
PS, the term "membrane" is not the same as the term "filter" in RO units. Membranes are completely different from filters and are much more expensive to replace.
1 Stars By Y. Wang on 2017-11-19
I don't know which to trust, the meter or the C342 solution
As some reviews say that it is not accurate, I bought this TDS-3 together with the HM Digital C342 solution. Unfortunately, the meter I received is another uncalibrated meter. It only reads 159 in C342 solution, which is supposed to be 342. I requested a replacement and received a new meter today, the new one reads 167, still way off the supposed 342. Now I really don't know, are this batch of meters all not calibrated? or the calibration solution I got is bad?
4 Stars By rr on 2016-01-04
Decent meter...glad I got it..found my water filter does NOTHING!
Was initially startled when it told me I had 550 ppm in both tap & filtered. I then checked CG Spring water which read 195.. The ppm is very small to read so I figured I must be reading downside up. When I rechecked I got ~100 in both.
Why on earth would they have 095 instead of just 95 is beyond me but it got me messed up initially. So basically there should have been an arrow instead of them playing 58008 with us. Removed one star for making me cuss my municipal water.
And as some people indicated, it does vary on temperature, but this is a cheap instrument meant to measure at room temps, not in beakers in a lab.
5 Stars By Jay on 2015-12-02
Holds calibration for a month or more. When you ...
Holds calibration for a month or more. When you do need to re-calibrate, it is simple and fast. This thing corrects for temperature variation and all. I have had one for two years, and it still has the same batteries. They will run out now that I mentioned it.
5 Stars By Bill Nomad on 2014-07-09
If you buy filtered water, you need this tester. It tells me the quality of water you drink. Govt standards for healthy water is under 500 ppd or particles of stuff in the water. My tap water comes out at 674 ppd. I will not drink it and buy bottle water in three gallon jugs. Osmosis filtered bottle water always measures under 10 ppd which is healthier and definitely tastier. Makes better tea and coffee, too. There is a cheaper tester but it is hard to read,. This one has a button that holds the reading so you can test and then put meter under light to read the numbers.
5 Stars By ZacharyMH on 2014-09-03
Easy to use and accurate!
I used this to compare the water quality in my tap water to that of different bottled waters. I wanted to prove to my wife that the "bad taste" in the cheaper bottled water was just in her imagination, since she doesn't like to buy off-brands. But to my surprise, this Meter showed the off-brand bottled water to be not much better than our tap water, whereas the Ozarka Spring Water was way more pure. (I'm not plugging Ozarka. In fact, I'm probably going to install a reverse osmosis machine under the sink bc I'm tired of carrying the bottled water home from the store. I'm also disgusted with the fact that our city doesn't have stricter water quality guidelines.)
This isn't something I'll use everyday, but it sure is nice to know I can confirm why the water we drink ever doesn't taste right.