Accu-Chek Compact Plus Manuel De L'utilisateur page 109

For each of these three periods you can ask the meter to display the
lowest and the highest values.
Average
When one of the three averages is displayed:
Press and hold down the M button to view the lowest value.
Press and hold down the S button to view the highest value.
As long as you hold the M button or S button down, the lowest blood
glucose value (and the highest blood glucose value, respectively) which
you obtained within the period in question is displayed along with its
time and date. If, for instance, the 7-day average was shown, then the
lowest or highest value relates to the last 7 days.
Using the meter as an electronic notebook
Lowest value
Highest value
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