Manual
LCom
Page 122 of 158
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Precip. Int. Factor:
a factor used to weight the precipitation intensity in
calculating the simulated water film height
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Evaporation Factor:
a factor used to weight the evaporation value calculated
from air temperature and relative humidity when calculating the simulated
water film height.
The model calculation is based on the following sequence:
Step 1: a “smoothed” water film height is calculated from the current measure value
and the last smoothed water film value, using the configured time factor and
decrease delay. The result of Step 1 is the “smoothed” value if the smoothed value is
higher than the measured value, otherwise the measured value is reported as the
result value (i.e. only decreasing values are smoothed, increasing values are taken
on from the sensor).
Step 2: if a precipitation intensity value is available, a simulated value for the water
film height is derived from the precipitation intensity and the last calculated simulated
water film height.
If air temperature and humidity values are available, an additional model is used to
calculate the evaporation of water from the road surface, and this value is deducted
from the simulated water film height calculated from the precipitation intensity.
The total result is the higher value from Step 1 and Step 2 (if Step 2 was calculated).
The result is a smoothed and/or simulated water film height in mm.
