Preparation
17
© 2017 Nortek AS
5.2
Before Mission
With the previous sections of this chapter successfully completed you are now ready for your final
preparations before deployment.
It is vital to remember to connect the dummy plug in case the connector is not to be used, to
protect it. Before mating, ensure that the connectors are dry and free of debris, look for water
inside the female connector.
When properly mated, the engaging nut on the cable plug will thread smoothly onto the receptacle
shell until it rather abruptly reaches a point where it cannot be hand-tightened any further. At this
point the mating surfaces of the plug and receptacle are in contact, and have formed a good seal.
The amount of force required to tighten the engaging nut should stay the same throughout (up until
the point where it cannot be further hand-tightened). Otherwise, the connectors are not mating
properly and will not form a good seal.
We recommend starting new missions with an empty recorder if you plan to store data internally.
Before you
erase the recorder
, make sure that you have transferred all the data you want to retain.
Set a pressure offset. The DVL measures absolute pressure. The pressure offset selected is the
pressure reading for offsetting absolute to relative pressure. Atmospheric pressure is typically 10.0
dBar, while factory setting is 9.5 dBar to get non-zero readings out of water. Change this offset
through the web site (under Instrument settings - see screenshot below).
Online connectors should be lubricated with silicone spray.
The Mounting Angle should be set to the non-zero value if the the DVL's X direction is different
from the vehicle's or INS's forward direction. See the section on
Coordinate System
for further
clarification.
