1 Preparing the EK80 for calibration
Prior to calibration, you must check that your EK80 is fully functional.
Context
A fully functional EK80 system is vital for a successful calibration. It is necessary to measure the environmental conditions before the calibration starts.
Procedure
1 Start the EK80 program.
a Check that the EK80 and all the transceivers and transducers are installed correctly.
b Set Operation to Normal.
c Start "pinging".
d Verify that the EK80 is fully operational on all channels.
2 Measure the water salinity and temperature between the transducer and the planned depth of the calibration sphere.
3 Calculate the average salinity and temperature values, and type these into the Environment dialog box.
The sound velocity is automatically calculated by the EK80. The corresponding absorption coefficient is calculated by the echo sounder according to Francois & Garrison, JASA December 1982.
Note
When you calculate the target strength (TS), you must use the sound velocity at the depth of the sphere.
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Sound speed in water for different salinity values
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Sound absorption for different salinity values