Review on 📏 Enhanced Precision: Extra Large Buffer Calibration Kit - The Ultimate Tool for Accurate Measurements by Wayne Ohlrogge

I bought these to test the Dr.Meter PH002. A pH 7 buffer solution is essential to zero the flow meter. Using distilled water from the grocery store, the meter read a pH of 5.9, likely because distilled water normally absorbs CO2 from the air and can be quite acidic. You need a pH-buffered solution with a neutral pH to ensure your solution is truly neutral. The other two solutions will let you know if the scaling factor is correct (which you can't adjust on this gauge). The kit comes with MSDS data but no instructions.