Service manual

Calibration

28 P2260/E

n is the plane wave sound pressure in

front of the transducer Pa

= I

D c

D is water density = 1000 kg/m

c is the speed of sound = 1500 m/s

NL = 20 log n + 120 dB re 1 µPa

120 dB is introduced for conversion from Pa to µPa

For the reason of documentation it is recommended to record one scope plot

at survey speed.

Select the Printer-1 Menu/Echogram-1 Menu and set:

Presentation: Scope.

When the scope printout has started, set:

Presentation: Normal

Repeat the measurement for transceiver 2 and 3 (if installed).

References

ICES Cooperative Research Report 144:

Calibration of acoustic instruments for fish density estimation: A

practical guide.

ICES, Palægade 2, 1261 Copenhagen K, Denmark

ICES Fish Capture Committee 1981/B:20

Improved calibration of hydroacoustic equipment with copper

spheres. By Foote, Knudsen, Vestnes, Institute of Marine Research,

Bergen and Brede, Nielsen, Simrad Subsea Horten, Norway.

Journal of the Acoustical Society of America, March 1983.

Maintaining precision calibrations with optimal copper spheres By

Ken Foote.