HM Digital C342 TDS and EC Calibration Solution, 342 ppm (NaCl), 90 ml Volume, Transparent/Blue

It is good to have this to calibrate my TDS tester. I have never needed to calibrate my tester but decided to make sure that it still works after 3 years ilof periodic usage. Only issue is the cost and there is so much of it that I won't need to use again for a few more years.

I have used this to calibrate my to different TDS meters. One I cannot calibrate but it only reads a little over the stated TDS on the bottle. I use this to calibrate my TDS meter that I mainly use to keep RODI filters in check for reef tank. So far it has worked prefectly and would definatly recommend to someone else or buy again.

No problem with calibration solution. Only a problem with me, calibrating my Digital meter....Maybe its the meter that's squirrelly...?

I had a lot of problems doing calibration with my HM DIGITAL TDS-3 METER was getting 320 then 411 then 422 then 511 then 477 readings. I thought something was wrong with the solution but I have since found out that the HM Digital TDS-3 I bought is a knock-off FAKE and so it is not the solution like you said, it's the meter itself. I contacted the manufacturer HM DIGITAL and sent them photos of the meter Amazon shipped to me and they instantly said it was a FAKE.NOTICE TO EVERYONE: A real original HM Digital TDS-3 meter will have these traits:1. when you turn the meter on it will show "HM" in the display for a second or two then it will display 000 but it must show HM when you first turn on2. a real one will have 5 bumps on each edge of the front, not just in the photo on description page, but on the actual product itself. if it doesn't have the 5 bumps on each side it is a fake3. it will have instructions how to calibrate in black letters on the back along with a hole and a screw to calibrate it manuallymany amazon sellers have these traits in their photos but when the product arrives it doesn't have the 5 bumps on each side, doesn't have the calibration printed in black on the back with a screw to calibrate, and doesn't show "HM" when you first turn it on across the screen. the HM will be big and easily see when you turn it on.BTW: MANUFACTURER CONFIRMED THIS IS THE REAL HM DIGITAL CALIBRATION SOLUTION

Great product to insure TDS meter results are accurate and reliable. A necessity. Recommend

I had recently bought a TDS meter ( HM Digital TDS-3 Handheld TDS Meter With Carrying Case, http://www.amazon.com/gp/product/B000VTQM70/ref=cm_cr_ryp_prd_ttl_sol_11) for home use.This 342 ppm TDS calibration liquid is must for the meter. Although the meter description says it doesn’t require calibration but it is always good to calibrate it.It comes in a very sturdy plastic bottle, which is leak-proof.You always need at least two calibration points to correctly calibrate a metering/measuring device. Therefore, I also bought another calibration liquid for 1000 ppm (HM Digital 1000ppm TDS Calibration Solution: http://www.amazon.com/gp/product/B001FD6WZ8/ref=cm_cr_ryp_prd_ttl_sol_0 ).Many people have mentioned that you can make the calibration liquid at home by dissolving a known amount of sodium chloride in water. I would like to mention that its wont be a good idea. First, the water itself is not pure and you don’t know what is its PPM value. Second, and important, weighing 0.1 to 0.5 g at any weighing balance we have at home is impossible. So spend some money and buy it. You wont regret it.I calibrated the meter with bot solutions and then measured a few liquids f known ppm value and the reading I got was fairly accurate (within 5% of actual).Always clean you TDS meter thoroughly before dipping it in the calibration liquid. Else you may change the concentration of the liquid, which will lead to wrong reading from your test water sample.!!!!!!! I STRONGLY ADVISE TO BUY THIS CALIBRATION LIQUID WHEN YOU BUY A TDS METER !!!!!!

Short of making calibration solution yourself, this is must have calibration solution for the HM COM-100 TDS digital meter. This calibration fluid can be used to calibrate any NaCl TDS tester. Which calibration fluid you buy will depend on what your testing needs are. Do you need KCl or NaCl calibration fluid? If testing pool or spa water, you'll want this type of calibration fluid, NaCl calibration fluid. The calibration solution also comes in 1000 ppm. You want to calibrate using the calibration solution that closely matches your daily testing needs. If you're going be testing household water, you're best served by the 342 ppm calibration solution. If you're going be testing pool/spa water you're best served by the 1000 ppm calibration solution.To calibrate the HM COM-100, place the meter in calibration mode by holding the middle button for a few seconds until the screen displays "CAL", lower the tester directly into the calibration fluid container and use the up/down arrow to scroll the numbers displayed on the scree until the digital display matches the calibration fluid concentration. It's that easy.You're now ready to test your water.Hope the above helps.

The numbers were wayyy off so not sure how to read anything else now. Showing my bottled water level too to compare.