Version 5.0 DUT-E Installation Manual
© 2007-2011, JV Technoton 22 of 30
2.12 Measurement precision check
All DUT-E are calibrated on diesel fuel by the manufacturer. In case of another type of fuel
or another diesel fuel (the arctic type, with additional purification, etc.) you may need re-
calibration of DUT-E (digital) or making adjustments into the calibration table of the
recording device.
2.12.1 Basic issues
Measurement precision check is needed to detect the relative and absolute measurement
inaccuracy of DUT-E on the vehicle.
In order to check the measurement accuracy of DUT-E you should make control tests, i.e. to
fill in and pour the fuel out from the tank, compare DUT-E readings with the actual filled-
in/drained fuel.
Fuel discharging is done by manual or mechanical pomp.
Test conditions:
a)
tests must be performed on a horizontal even surface;
b)
vehicle loading should not be changed during the procedure;
c)
wheels of the vehicle must be standard size;
d)
the tire pressure should correspond to the pressure set by the manufacturing factory
for the given vehicle;
e)
the vehicle must remain motionless, ignition on, engine is stalled;
f)
the amount of fuel discharge and filling must be not less than 20% of the length of
the DUT-E measuring part;
g)
a pause of at least 15 minutes should be done between consecutive operations of
fuel discharge and filling;
h)
it is not allowed to switch off the ignition and "ground" of the vehicle during the final
discharge – filling operation;
i)
during testing it is necessary to use verified containers to determine the volume of
the discharged or filled fuel.
2.12.2 Control test steps
a)
start up the ignition;
b)
discharge the fuel of a certain volume;
c)
determine the discharge volume with the help of the verified measuring device;
d)
record the data into the protocol control tests (Appendix 3);
e)
make a pause in order to stabilize the fuel in the tank (before stabilizing of DUT-E
readings);
f)
refuel the tank on the amount of the earlier drained fuel;
g)
record the amount of the fuelling into the protocol;
h)
by analyzing the inaccuracy, the parameters "Drain" and "Refuel" are estimated in
percentage relatively to the tank volume. Calculation formulas are given in Appendix
3.
