User`s guide

Dexcom G4 User’s Guide | 49
The Dexcom G4 System requires you to calibrate the sensor
glucose readings to your blood glucose meter.
4.1 CALIBRATION OVERVIEW
There are important times when you must calibrate:
1. Initial startup: 2 hours after you insert your sensor
2. 12 hour update: every 12 hours after the initial startup calibration
3. More information needed or other reasons
When calibrating, you need to manually enter your blood glucose values into the
receiver. You can use any commercially available blood glucose meter.
On the rst day of your sensor session, you will need to enter 2 blood glucose
values into your receiver as your 2 hour startup calibration. After your 2 hour
startup calibration has been entered, you will need to enter 1 blood glucose
value as your calibration at 12 hours after your startup calibration. From that
point on you will need to enter 1 blood glucose value every 12 hours. The
receiver will remind you when these calibrations are needed. You may also be
prompted to enter additional blood glucose values as needed. An example of
your minimum calibration schedule during a seven day sensor session is shown
below:
Taking acetaminophen (paracetamol) containing products (such
as Tylenol) while wearing the sensor may falsely raise your sensor
glucose readings. The level of inaccuracy depends on the amount
of acetaminophen (paracetamol) active in your body.