Silva NX2, Service Manual

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80deptraNX2.doc Page 2 Latest update: 3 Jan -03
Below are listed some explanations or possible technical faults for
disturbances to the measurement of depth and how it is expressed on the
instrument display
.
1. There is no depth reading on the display. Only ( - - - ) is displayed:
If it has not worked before.
•
Connection from Server to transducer broken.
•
Check installation, cables and connectors
•
Listen for transducer clicking. You should hear 3 clicks per second.
2. Unstable or periods of - - - readings.
If there are no depth echoes for some seconds, the display indicates 3 dotted
lines ( - - - ) until a new echo is received.
•
In deep water outside the range of the transducer.
•
Combination of deep water and soft bottom makes it difficult to reflect the
signal.
•
When the boat is heeling heavily, for example when sailing.
•
Inside hull mounting, hull to thick or trapped with air. Or to little liquid in pipe.
3. Jumpy or erratic readings.
•
In a propeller stream, where air bubbles are created. E.g. when powering
astern or when following close behind a power boat.
•
When going over shoal water, with uneven and high bottom vegetation.
•
In heavy layers of salt or noticeable ranges of water temperatures.
•
In heavily agitated water containing particles of sand or some other
contamination.
•
When a boat is moored in a harbour with other boats around, there can be
disturbances from signals from other depth transducers, chains or other
mooring equipment.
•
Electrical noise in the boat. OK when sailing but not with motor?
•
Paint or weed on transducer. Clean at regular intervals.
Important: Do not cut or extend the depth transducer cable!
Trouble solving
If no natural cause to wrong or no depth readings can be found the most crucial
part is the NX2 Server where the signal processing takes place.
See § 5.6 NX2 Faultfinding Guide and §6.0 Server.