Moog Tritech Super SeaKing 700 V7 Series, Руководство по эксплуатации продукта

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20 0688-SOM-00001, Rev: 02 © Tritech International Ltd.
Relative Measurements
For relative measurements there is no requirement to zero the unit on deck because any error at the surface will
represent a constant offset (gravity effects are also negligible).
The important parameters are variations in atmospheric pressure, water column mean density and tidal
corrections for the duration of the measurements. See Section 4.2, “Pre-dive Setup”.
SeaKing 700 units may be mounted in any orientation and with the correct atmospheric pressure entered
an approximate zero offset can be entered such that the output depth reading is zero while on deck. It is
recommended that no further alteration is made to the zero settings for the duration of the job. See Section 3.9,
“Bathy Offsets”.
Absolute Pressure
All of the factors affecting measurement as detailed in the above sections will apply and any zero offset applied
will also need to be known.
The pressure sensor fitted to the Super SeaKing 700 series heads is temperature compensated, however, it can
take up to 2 hours for the sensor to stabilise (if the external temperature is varying considerably this time will be
longer). To get a reading the unit needs to be powered up and allowed to stabilise completely. If removing from
the seawater to a deck that is a very different temperature then the readings can have a significant error.
There are two alternative approaches to setting the zero offset:
1. Ensure the unit is mounted either port up or port down and use the zero offset figure published
on the build and calibration sheet for the instrument. This figure should not be altered unless a full
check is completed (i.e. follow step 2 below) even if errors are showing while on deck. The results at
depth will be consistent and accurate.
2. Perform a thorough deck zero check as follows:
• Keep the unit at a temperature close to seawater (i.e. use a bucket and ice/hot water as
appropriate).
• Power the unit for a minimum of 2 hours to allow stabilisation to occur.
• Obtain correct values for atmospheric pressure and latitude and enter them into the
system.
• Set the position offset currently in the system to zero.
• Remove the SeaKing 700 series head from the vehicle and lower to a known depth.
• Adjust the zero offset so that the depth reading matches the known depth.
Note
If setting the zero offset using method 2 it will be necessary to do so with the
SeaKing 700 head vertical with the sensor cage at the bottom (i.e. port down)
and subsequently the unit should always be used in this orientation.