Active Care Medical TD-4121 Owner's Manual page 28

We strongly recommend that you perform AST ONLY at the following times:
 In a pre-meal or fasting state (more than 2 hours since the last meal).
 Two hours or more after taking insulin.
 Two hours or more after exercise.
Do NOT use AST if:
 You think your blood glucose is low.
 You are unaware of hypoglycemia.
 You are testing for hyperglycemia.
 Your AST results do not match the way you feel.
 Your routine glucose results often fluctuate.
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