Hanna HI7061M General Purpose Electrode Cleaning Solution 230mL RO water testing Simple two point calibration for increased DIN connector electrode Simple two point calibration for increased pH accuracy with manual trimmers for easy adjustment reliable free chlorine monitoring with the Milwaukee MI526 100 — 100 pre measured DPD powder reagent packets formulated specifically for the Milwaukee MW10 Free Chlorine Photometer If the mV offset continues to deviate and the meter is calibrated with a dirty electrode then inaccurate readings will result The most common cause for pH measurement inaccuracies is an unclean or improperly cleaned electrode