How To Measure Range; How To Show/Hide The Range Rings; How To Measure Range With The Variable Range Marker (Vrm) - Furuno FAR-2228-BB Operator's Manual

1.32

How to Measure Range

The range to a target can be measured three ways: with the fixed range rings, with the
cursor, or with the VRM.
Use the fixed range rings to get an estimate of the range to a target. The rings are the
concentric solid circles on the display. The number of rings is automatically set by the
current range scale. The distance between the rings is the range ring interval, and the
current interval appears at the upper-left position on the screen. To measure the range
to a target with the range rings, count the number of rings between the center of the
display and the target. Check the range ring interval and estimate the distance of the
echo from the inner edge of the nearest ring.
1.32.1

How to show/hide the range rings

1. Open the menu.
2. Select [3 NAV TOOLS] to show the [NAV TOOLS] menu.
3. Select [4 RANGE RINGS].
4. Select [ON] or [OFF] as appropriate.
5. Close the menu.
1.32.2

How to measure range with the variable range marker (VRM)

There are two VRMs, No. 1 and No. 2, which appear as dashed rings so that you can
distinguish them from the fixed range rings. The two VRMs can be distinguished from
each other by the different lengths of their dashes; the dashes on the No. 2 VRM are
longer.
270
260
There are two methods for measuring range with the VRMs, using the VRM key and
on-screen menu box operation.
Range to VRM
350
340
330
320
310
300
290
280
250
240
230
220
210
200
190
VRM1
28.11 36.44
NM
TTG 50:00 TTG
TTG to VRM
000
010
020
Target echo
030
040
050
060
070
110
120
130
140
150
160
170
180
VRM2
Currently active VRM is highlighted.
NM
60:00
1. OPERATIONAL OVERVIEW
VRM1
080
090
VRM2
100
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