Furuno FCV-582L manual Erasing Weak Echoes, Measuring Depth

1.10 Erasing Weak Echoes

Dirty water or reflections from plankton may be painted on the display in green or light- blue. These weak echoes may be erased as follows:

1.Press the SIG LEV key. The following display appears.

	SIGNAL LEVEL		SIGNAL LEVEL
	▲ OFF		▲ OFF
		SL1		SL1
		SL2	▼	SL2
		SL3		SL3
		SL4
			(At 8-color display)
		SL5
	▼ SL6
(At 16-color display)

Figure 1-21 Signal level display

2.Press the SIG LEV key again to select sig- nal level (echo color) to erase. The color deleted disappears from the color bar and is replaced with dark-blue color. SL1 erases the weakest echo; SL6 the light- blue echo.

Weak echoes

Signal level adjusted

Figure 1-22 How SIG LEV works

1.11 Measuring Depth

The VRM (Variable Range Marker) functions to measure the depth to fish schools, etc.

1.Press the [▲] or [▼] key to place the VRM on an echo.

2.Read the VRM range just above the VRM.

200k

0.0 0

VRM (green) 20

39.8

40

60

49.680

Figure 1-23 How to measure depth

with the VRM

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