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Appendix
1. Lambda (Lambda: air surplus rate) Calculation Formula
Lambda is not the value measured from the vehicle exhaust gas, but is a constant
calculated based on the Bretschineider formula that measures the density of
CO, HC, CO2 and O2
and applies the percentage of H, C, and O of vehicle gasoline.
Bretschineider formula
▶
Enter the density (%) of CO, HC, CO2, and O2.
▶
K1
: Enter constant 6 or 8 for vapor in combustion stroke.
K1 is the constant that converts the value measured by Non Dispersed InfraRed
(NDIR) into the value measured by
Flame Ignite Detect (FID)
and meets the
specification of 4 gas analyzer manufacturer.
▶
Hcv
: Rate of C(carbon) to H(hydrogen) of the fuel
▶
Ocv
: Rate of C(carbon) to O(oxygen) of the fuel
Lambda is the value calculated based on the density of CO, HC, CO2, O2 of
gasoline gas and percentage of gasoline (C8H18) elements. Therefore,
measuring 4 gases accurately is prerequisite to the Lambda calculation.
