User manual HANNA INSTRUMENTS HI 991000

[. . . ] Battery replacement The meter displays the remaining percentage when turned on. When the battery level is below 5%, the - + symbol on the bottom left of the LCD lights up to indicate a low battery condition. [. . . ] All the used segments on the LCD will be visible for a few seconds, followed by a percent indication of the remaining battery life. To turn HI 991000 off Press the ON/OFF/MODE button from normal measuring mode. To freeze the display Press the SET/HOLD button for 2 seconds until HOLD appears on the bottom display. Press any button to return to normal mode. · Press the SET/HOLD button for changing the buffer set. · Press the ON/OFF/MODE button to return to normal pH measuring mode. pH calibration · Press and hold the ON/OFF/MODE button for 3 seconds, until OFF on the bottom display is replaced by CAL. The LCD will display pH 7. 01 USE or pH 6. 86 USE (if you selected the NIST buffer set). · For a single point pH calibration, place the probe in any buffer from the selected buffer set (eg. The meter will recognize the buffer value and will display OK for 1 second. If the pH 7. 01 buffer (or 6. 86 if you selected the NIST buffer set) was used, press the ON/OFF/MODE button to return to the pH measuring mode. · For a two point pH calibration, place the probe in pH 7. 01 (or 6. 86, if you selected the NIST buffer set). The LCD will display the recognized buffer value and OK for 1 second and then display pH 4. 01 USE. Place the probe in the second buffer value (pH 4. 01 or 10. 01, or, if using NIST, pH 4. 01 or 9. 18). [. . . ] · Press the ON/OFF/HOLD button again to show the current buffer set: pH 7. 01 BUFF (for 4. 01/7. 01/10. 01) or pH 6. 86 BUFF (for 4. 01/6. 86/9. 18). To reset to the default calibration To clear a previous calibration, press the ON/OFF/MODE button after entering the calibration mode. The bottom LCD will display ESC for 1 second and the meter will return to normal measuring mode. [. . . ]