34  Dover Fueling Solutions    W2940305    Rev 07    8/2019 
4.6  Meter Check (Calibration) 
4.6.1 General 
  Select dispensers use the intelligent iMeter fuel meter (or Xflo fuel meter for E85 
dispensers) to measure the fuel dispensed.  For the sake of calibration, the 2 meters act 
identically concerning calibration.  For Super-high capacity models, both sides of the 
meter are used to increase flow.  The maximum meter calibration range is +3.85%. 
  The meter is equipped with an intelligent pulser with two sets of sensors; one set for each 
meter. On the front of the pulser, there are two calibration doors; one for each meter in 
the meter module. The door closest to the front of the dispenser controls calibration of the 
front meter and the other door controls calibration of the rear meter (enhanced capacity 
singles do not have a rear meter). 
  All meters are tested, calibrated, and sealed at the factory before a dispenser is shipped. 
As part of the start-up procedure, the accuracy should be verified, and if re-calibration is 
required, the calibration procedure should be followed. To thoroughly flush out all air and 
completely fill the system prior to verification and calibration, dispense product from the 
dispenser (and satellite if applicable) until a continuous and steady flow of product is 
observed at each nozzle. 
  In applications involving the resale of fuel, for the initial use and after any adjustments to 
the calibration, the meter will need to be sealed by the appropriate Weights & Measures 
authority. 
4.6.2 Accuracy Verification 
Step 1  Dispense product into a certified 5 gallon or 20 liter calibration container to wet the 
container and then empty it back into the tank, allowing it to drain for 10 seconds. 
Step 2  Dispense product into the container until exactly 5 gallons (20 liters) are shown on 
the dispenser display. 
NOTE:  When temperature compensation is activated (Canada), the dispenser should 
be placed into Temp Comp Fueling Mode (reference Appendix G), so that the 
accuracy can be verified using the gross (uncompensated) volume shown on 
the display in this mode. 
Step 3  Compare the reading on the container’s sight glass to the dispenser display. For 
the “Acceptance” test, the container volume should be within a total of +/- 1 cu. in. 
plus +/- 0.5 cu. in. for each gallon dispensed for a 5 or 10 gallon prover.  For larger 
provers, the acceptance tolerance is +0.3% (units rated up to 30 GPM). 
NOTE:  For U.S. weights & measures applications, acceptance tolerance of +/- 1 cu. 
in. plus +/- 0.5 cu. in. for each gallon dispensed (into a 5 or 10 gallon prover) 
and 0.3% into a larger prover, is required for newly placed in service devices 
for 30 days. After 30 days, the maintenance tolerance is increased to +/- 1 cu. 
in. plus +/- 1 cu. in. for each gallon dispensed (into a 5 or 10 gallon prover) 
and 0.5% for larger provers.  Consult Handbook 44 for full information. 
NOTE:  If dispensing DEF, properly dispose of the DEF from the can (see WARNINGS 
in front of manual.) 
Step 4  If the values are out of range, follow the calibration procedure in Section 4.7.3.