Look at another one.  This is a very poor quality meter.
935617
This thing is junk.  It stopped working after the second pH measurment for my kids science project.  We replaced the batteries and no change.  The LCD display stopped working.  I have no idea if the meter itself is working but we cannot read the pH.  Returning to Amazon.
832584
Pretty poor quality device. It worked great for 2 weeks, then the timer stopped working. It would only come on if I turned it on manually. Did like the dual outlets. Woods, fix your quality control. I'd pay a few more bucks for a quality device, which would probably mean 10 cents for you.
3166223
I am not sure if I got a dud, or if this is just made too cheap. I bought it to test water hardness and it appears to work, however, after getting the initial reading, if you move the tester or just barely tap it, the reading jumps up about 50 ppm or so. So it is virtually impossible to know what the actual correct reading is. That being said, I returned it. I bought some paper testing strips and they were much more accurate imo.
2560794
No ta  good meter at all,half the time it didn't work, now it doesn't work at all.
2892226
I have owned two Hanna HI98129 meters.  They worked well but mine have had a short life.  The first lasted a year.  The second just lasted 5 months - screen just went blank and refuses to turn on.  !@#$%^&  Guess I'll be moving on to a find a more reliable meter!!!

I ended up with a bluelab truncheon meter.  Appears relatively bullet proof.  Will report back my thoughts.
238216
Low quality, low power. I barely use it. Skip Amazon and go to Harbor Freight Tools where you can see how bad it is and then get a better quality one. Sorry Amazon.
3243656
The tester either isn't calibrated correctly, is of poor quality, or it is defective.  I have tested over a half-dozen BRAND NEW batteries of different sizes and every battery test out as "low".
546308
while this is a cheap meter, it is better suited to a 10-15 year old--the quality is poor and the teat lead appear to not be suited to "real" high voltage and accuracy. I would not buy this meter again.
139559
I don't know if it was because of the poor packaging or if the unit was a used returned item, but this meter did not work. Upon opening the shipping box I saw a plastic case with a meter hanging out of it. The meter was also on. That was strange because there were clearly three slots to hold the batteries in the case.

I tried to calibrate this meter with no success. The numbers would just jump all over. And it would only register within 6.2 to 6.8 after adjusting to the 6.8 solution when placed afterward in the 4.0 calibration water. (I did use distilled water for mixing the two calibration packets.)

Another note of interest is that the adjusting screw is on the backside. That made it difficult to adjust when looking at the display.

The instructions were written by a Chinese worker who had just learned English and probably failed the class.

I hesitated to buy this because it was so inexpensive. Inexpensive does not count when a unit does not work. This item was returned. Thankfully Amazon has a good return policy.

My next unit will be a professional grade meter with a self adjusting function.
1856161
this is a bad quality equipment. does not work very well. i have to reset it everytime by inserting into the USB port of my computer. all the devices connected to its port don't work properly. i have changed the USB port of my computer but it is still giving the same issue. i think it has manufacturing defect.
3281234
This is junk!  Went through 3 of these before getting one that partially worked.  And the meter is not even close to being accurate.  Don't be fooled by other brands...  if it looks the same, it is the same.  There are a number of these on amazon under different brands.  Same garbage!
1472067
Low quality product even for price. Casing of the meter was poorly made and there is one less sensor than others so accuracy can't be trusted. I've added photos of this meter compared to an other of equal value. THZY high accuracy meter had been working great I just damaged the glass probe a bit while i was using it.(was not able to add photo) photo shows two sensors on bottom and glass probe on THZY  and only one sensor on bottom and a glass probe for this meter. Also shows defects on bottom of yellow housing were the probe comes out.
1612715
This meter was Not what I expected....  I read a bunch of reviews of the meter. And they were mostly positive.
But after receiving mine, I truly cannot understand why! The build quality Is cheap and crappy. The readings are inconsistent and inaccurate! And the leads feel like flimsy toothpicks I your hands.
If I could go back and do it again I'd spend a little more and buy a decent meter. While this meter was cheap, it was a total waste of money. Trust me,  find something else!
793556
The meter stopped working after a few days. I will send it back. I would have paid an extra $10 for better quality. It is cheaply made
3561061
Not very accurate.  After returning one meter due to it being wildly inaccurate (always pegged the needle fully to the right whenever plugged in) The replacement I received is also very inaccurate, showing 130V when plugged into an outlet that was tested at 122.5 Volts with a professional Fluke multimeter.
4519415
After a couple of days of use, I have decided that I don't trust the readings this meter is displaying. At least the $5 and $10 meters I have owned in the past displayed a number and stayed there. This one seems to flutter around a lot. I don't know if it is the connectors, the probes or the circuitry. The selector dial sometimes produces the desired result and sometimes not (dial Volts and get Ohms). Never got the continuity check to beep. It is going back.

All the positive reviews influenced my decision to buy, but on closer inspection I see that the more recent ones cite similar quality problems.
203635
I bought this three years ago. At the time, my car battery was dying. This meter didn't provide especially "actionable" information to conclusively show me what was going on. I ultimately just replaced the battery and everything was fine.

Now, I wanted to use the meter again to monitor battery problems on other cars. The meter is dead as a doornail! Nothing lights up when I put it three cars I tried, including one with no battery issues at all. So, this meter is not very durable to stop working after light usage.