If you know that you will be testing for acidity, you will usethe 6.86 solution and the 4.0 solution.
If you know that you will be testing for alkalinity you will usethe 6.86 solution and the 9.18 solution.
If unsure, it is recommended using the 4.0 solution as thesecond point of calibration.
Step 1: Mix each of the two chosen buffer powders in 250ml (approximately one cup) of distilled or deionized water.
Step 2: Insert the tip of the pH meter into the 6.86 solutionand push the ‘cal’ button in and hold in for 3 seconds beforereleasing. (This initiates the calibration procedure.)The meter will begin flashing 6.86.Gently swirl until the reading stabilizes.
Step 3: If Using the 4.0 solution :
Insert tip of meter into the 4.0 solution. Press and hold the ‘cal’ button for 3 seconds before releasing, the meter starts to flash 6.86), and then immediately press and release again (without holding it infor 3 seconds) and the meter will begin to flash 4.0. Gentlyswirl until the reading stabilizes.
Alternate Step 3: If using the 9.18 solution as the secondpoint of calibration:
Insert the tip of the pH meter into the 9.18 solution andpush and hold in the ‘cal’ button for 3 seconds beforereleasing (the meter will start to flash 6.86) and then immediately press and release twice more without holdingin the button and the meter will flash 9.18.Gently swirl until the reading stabilizes.
For each solution, the ‘cal’ button needs to be ‘activated’ byholding it in for 3 seconds. Then press and release oncemore for the 4.0 solution…OR… press and release TWICE more after the initial hold in for the 9.18 solution.
If you still have problems,please refer to youtube link:https://youtu.be/Yi42DcIluYo
1 x Digital PH Meter
1 x 6.86 buffer powder
1 x 4.01 buffer powder
1 x User Manual