When Must Be Correction Of Ph Tester

 In the following circumstances, the Ph Tester must be to correction(1) solution temperature and correction of temperature  have great changes;(2) leave solution time too long electrode;(3) change with the new composite electrode;(4) measurement concentrated acid (pH < 2) or strong  alkali (pH > 12) after;(5) measurement contains fluoride solution and acidity  in pH < 7 solution or thicker after organic solution.(6) correction, please will PH correction fluid in  25 ± 1 ℃ temperature environment.