Gain Control (Gain) - Honeywell IntuVue RDR-4000 Pilot's Manual

IntuVue RDR-4000 Weather Radar Pilot's Guide

GAIN CONTROL (GAIN)

GAIN control is active in all modes
except TEST. The calibrated
(CAL) position is the same as
AUTO gain mode and is the only
position where the colors
represent the FAA defined
reflectivity and rainfall rates as
shown in the table below. The CAL gain setting provides a standard
reference which all radar manufacturers must follow. Immediately after
turning the GAIN control in either direction out of the detent position
(CAL), the VAR annunciation appears on the display indicating that the
system is no longer in the calibrated mode. Rotating the GAIN control
counterclockwise decreases gain; rotating the GAIN control clockwise
increases gain. The gain setting has no effect on turbulence detection
or display. After using the GAIN control to assess the weather it should
be returned to the CAL position.
If the Hazard Display Configuration of the radar system is installed, the
GAIN knob can also be used to temporarily suppress the display of
Hazard Icons and Turbulence Indication. See HAZARD DISPLAY
SUPPRESSION on page 29 for details.
Color Returns
Very light or
Black
none
Green Light
Yellow Medium
Red Strong
Magenta Turbulence
In all modes except TEST, rotating the GAIN Knob to the minimum
(MIN) position reduces gain by approximately 16 dBZ. Rotating the
GAIN Knob to the maximum (MAX) position increases gain by
approximately 10 dBZ.
Proper use of the gain control can aid in the detection and assessment
of storm cells. Gain reduction can be useful in several ways. Reducing
the gain to MIN provides a quick assessment of the relative intensity
between displayed cells. Since gain does not affect turbulence
detection, reducing gain in the AUTO mode to MIN will show turbulence
060-4492-000
Rev 7, February 2015
Reflectivity Color Codes (Gain at CAL)
Reflectivity
Less than
20 dBZ
20 – 30 dBZ
30 – 40 dBZ
40 dBZ or
greater
N/A
Rainfall Rate
Less than 0.7 mm/hr
(0.028 in/hr)
0.7 – 4 mm/hr
(0.028 – 0.16 in/hr)
4 – 12 mm/hr
(0.16 – 0.47 in/hr)
Greater than 12 mm/hr
(0.47 in/hr)
N/A
Expanded Operating Instructions
27