Review on Accurate and Reliable VIVOSUN Digital PH Tester Pen for Water Testing by David Golden

Did this a long time ago. It would be better if the PH meter only showed a column of tens and didn't further break it down to hundredths. My personal preference what is the difference between 1.6 and 164? During calibration, the readings changed from 160 to 190, then 160 to 190, like a clock being reset. I probably wrote a book on calibration and have large bottles, not bags, to sample from. No "calibration" will reassure the reader. I left it in the tank to let it settle to the ambient water temp and the result is the same. I thought I would try. I am lost.