Dexcom G4 Professional User Manual page 172

fluid. Therefore, the readings from the blood glucose meter readings and
sensor may not match.
WARNING
Calibrate at least once every 12 hours. Calibrating less
often than every 12 hours might cause sensor glucose
readings to be inaccurate, and you might miss a low or
high blood glucose value.
PRECAUTION
To calibrate the system, enter the exact blood glucose
value that your blood glucose meter displays within
5 minutes of a carefully performed blood glucose
measurement. Entering incorrect blood glucose values or
blood glucose values from more than 5 minutes before
entry might affect sensor performance, and you might
miss a low or high blood glucose value.
If the difference between the sensor glucose reading and blood glucose
value is greater than 20% of the blood glucose value for sensor glucose
readings > 80 mg/dL or greater than 20 points for sensor glucose
readings < 80 mg/dL, wash hands and take another blood glucose
measurement. If the difference between this second blood glucose
measurement and the sensor is still greater than 20% for sensor glucose
readings > 80 mg/dL or greater than 20 points for sensor glucose
readings < 80 mg/dL, recalibrate the sensor using the second blood
glucose value. The sensor glucose reading will correct over the next 15
minutes. If you see differences between the sensor glucose readings
and blood glucose values outside of this acceptable range, follow the
troubleshooting tips below before inserting another sensor:
Dexcom G4 PLATINUM Professional System User's Guide | 171