Review on 💧 Digital Water Quality Tester with Calibration Kit - LiZi pH Meter by Wiktor Pozna ᠌

I did it according to the instructions: I took 250 ml of distilled water with a temperature of 26 degrees, diluted the bag with ph 4.01. The device showed 3.5. I tried to turn the screw - the values ​​\u200b\u200bdid not change. I did a similar operation with the second solution (ph 6.86) - the result is 6.0 Well, how to use this tester then? By the way, turning the screw is a separate art: it is easier to remove the upper black part with batteries, so that at least you can see where to insert the screwdriver. Too bad it doesn't affect anything.