3.2
Vapor Recovery Rate, corrected Vapor Recovery Rate
and Correction Factor
The self adaptation and checking of the vapor recovery system must be carried
out with air. Therefore the gas meter has to be connected via the adapter to the
dispensing nozzle. After calibration, the system will suck hydrocarbon vapor
under operating conditions. The fluidic behaviour of these vapor differs from that
of air. This difference is expressed as the correction factor (C-factor). All
specifications refer to the vapor recovery rate.
VaporRecoveryRate
This vapor recovery rate can refer to flow rates or quantities. The vapor recovery
rate displayed in the hand held terminal always refer to the flow rate. The legisla-
tive dictates an average vapor recover rate related to hydrocarbon vapor. The
displayed vapor recovery rate must be corrected by the correction factor due to
measuring the self adaptation data with air. The correction factor has been
specified by a legislative authority an is published in the approval certificate:
VaporRecoveryRate
The displayed vapor recovery rate related to air has to be higher than the one
dictated from the legislative. The correction factor can be adjusted with the self
adaption set. There is no need for a new calibration due to a change of the
correction factor.
For an easy checking of the system the corrected vapor recovery rate is
displayed too. It has to be in the dictated borders (in Germany 95 - 105 %).
Operating Instructions No. 893 193
VaporVolume
[%] =
HC-Vapor
FuelVolume [ l ]
[%] = CorrectionFactor x VaporRecoveryRate
Air
[ l ]
HC-Vapor
HC-Vapor
[%]
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