Vaisala FD12P - Manual (Page 77)

Chapter 4 _________________________________________________________________ Operation
VAISALA ________________________________________________________________________ 77
Snow Pellets Limit
The Snow pellets limit parameter specifies the minimum particle size
(in FD12P internal units), which is detected as snow pellets.
(Additional internal criteria are used before the precipitation type is
determined to be snow pellets.)
Snow Grains Limit
The Snow grains limit parameters refers to the maximum particle size
(in FD12P internal units), which is detected as snow grains.
Ice Crystals Limit
The Ice crystals limit parameters defines the maximum particle size
(in FD12P internal units), which is detected as ice crystals.
(Additional internal criteria are used before the precipitation type is
determined to be ice crystals.)
Hail Limit
The Hail limit parameters refers to the minimum particle size (in
FD12P internal units), which is detected as hail. (Additional internal
criteria are used before the precipitation type is determined to be hail.)
DRD Scale
The DRD scale parameter is the scaling factor for the calculated
intensity of the DRD12 surface sensor. The typical value for this
parameter is 1.5. The value is also good for a very clean DRD12.
When the DRD12 becomes dirty after some precipitation events, it
becomes more sensitive, especially for light rain. Thus, a smaller
value of the scale could be used.
Warm Limit
The Warm limit parameter defines a more flexible, maximum snow
reporting temperature limit, which is required in some areas. The
nominal value is +8
°C.
PRW Command
The Present Weather command (PRW) command, displays a verbal
format message.