The Two- Point Calibration is to be performed at least once a month, or after any maintenance to the meter. (Refer to the Hanna manual under “calibration”)
Please read through all the steps before beginning.
** Before you begin, please ensure you have a container of water to rinse the probe between the 2 buffer solutions during the calibration. If you have Deionized water, Distilled water or RO water (Reverse Osmosis) – any of these are preferred to tap water, however you may use tap water if necessary. Also, have some paper towel near by to dab the probe after rinsing.
Step 1:
Open Buffer Solution bottles 7 & 4 before beginning calibration.
Step 2:
Begin calibration by following numbers 1- 10 exactly:
1) Turn the meter on using the “Mode” button. Numbers will come up on LCD screen.
2) Push and HOLD “Mode” button, until “OFF” and then “CAL” are displayed, then release button immediately once you see “CAL” on the display screen.
3) The meter will display “7.0 USE”. (For Buffer 7)
4) Immerse the probe into the requested Buffer 7 and gently agitate the probe in the Buffer solution.
5) When the meter has recognized the Buffer 7 it will display “4.0 USE”.(For Buffer 4)
6) Quickly rinse off the bottom of the probe with water and shake probe or dab dry with a paper towel to prevent contamination of the Buffers. This must be done very quickly.
** For steps 7 & 8 keep your eyes on the display screen at all times as to not miss the “OK” displayed on screen for buffer recognition.
7) Immerse the probe into the requested Buffer 4 and gently agitate the probe in the Buffer solution.
8 ) When the probe has recognized Buffer 4 the meter will display “OK” on the LCD for one second. The “OK” appears very briefly and disappears.
9) If a good calibration has not occurred, the screen will display “WRNG”, please repeat the steps.
10) Now the probe is ready to take pH readings.