New pH tester help

[Rabeats2093]

Calibrating ph readers

So I purchased a ppm reader and a ph reader a while back they came with some calibration powders I followed directions for calibrating the ph reader to a tee dipped the pen in to calibrate it of course she was off …no matter how many times I tried the pen did not bring me to the number stated for each pack …I dried em off tried again …negative So a couple months later I’m regretting it and could use them seeing how I’m at a new place with peroxide injectors with the well and all that Okay so…

I bought new calibration powders and did it right let’s just say that reader is within .2 most of the time dead on