Hanna Instruments HI 2221 Instruction Manual

Also see for HI 2221: Instruction manual

14The stored calibration history to used issue error and warning messagesduring calibration to help ensure the highest accuracy.As electrode aging is normally a slow process, substantial changesfrom previous calibrations are likely due to a temporary problemwith the electrode or buffers.ERROR MESSAGESError messages appear if one or all of the calibration parameters are outof accepted windows. Calibration can not continue when these errors aredisplayed.WRONG BUFFERWRONG BUFFERWRONG BUFFERWRONG BUFFERWRONG BUFFERThis message appears when the difference between the pH reading andthe value of the selected buffer is too big. If this error message isdisplayed, check if you have selected the proper calibration buffer.CLEAN ELECTRODECLEAN ELECTRODECLEAN ELECTRODECLEAN ELECTRODECLEAN ELECTRODEThis error message indicates a bad electrode condition (offset out ofaccepted window, or slope under the accepted lower limit).Clean the electrode according to the Cleaning Procedure on page 36 toimprove its condition and repeat the calibration. This ensures theremoval of film, dirt or deposits on the glass bulb and reference junction.CHECK ELECTRODECHECK ELECTRODECHECK ELECTRODECHECK ELECTRODECHECK ELECTRODE alternating with CHECK BUFFERCHECK BUFFERCHECK BUFFERCHECK BUFFERCHECK BUFFERThis error message appears when electrode slope exceeds the highestaccepted slope limit. You should check your electrode and use freshbuffer.ELECTRODEELECTRODEELECTRODEELECTRODEELECTRODEThis message appears if the cleaning procedure performed as a result ofthe above two messages is found by the instrument to be unsuccessful.ENHANCED CALIBRATION MESSAGESENHANCED CALIBRATION MESSAGESENHANCED CALIBRATION MESSAGESENHANCED CALIBRATION MESSAGESENHANCED CALIBRATION MESSAGES