Simrad EY500, Инструкция по эксплуатации

Страница: 218 / 262

Calibration
16
P2260/E
Check the cable connection to colour printer-1.
Switch on colour-printer-1.
Select the Printer1 Menu and set
Integrator Tables: Number of the transceiver in use (if EK 500)
Echogram: Slave
The echogram recording will then be similar to the one at the display.
Read the measured s
A
-value, the red number in the integrator table after each
log interval. Calculate the theoretical s
A
-value as follows:
TS sphere = target strength of the sphere
F
bs
= backscattering cross section of the sphere
F
bs
= 10
TS sphere/10
r = distance between the transducer and the sphere
(read from the display screen, underneath the horizontal projection
window).
Q
= equivalent 2-way beam angle
(from the measurement data delivered with the transducer)
Q
= 10
dB-value / 10
4
B
r
0
2 .
F
bs
.
(1852 m/nm)
2
s
A
(theory) =
______________________________________
Q
.
r
2
where r
0
= 1 meter is the standard reference distance for backscattering.
If the measured s
A
-value differs from the theoretical value, this can be corrected
by changing the S
v
Transducer Gain in the Transceiver Menu. Calculate a new
transducer gain:
10 log (s
A
(measured)/s
A
(theory))
New transd. gain = Old transd. gain +
___________________________________________________
2
Enter the S
v
transducer gain in the Transceiver Menu, and the measured s
A
-
value will be correct.
The calibration report form at the end of this appendix may be used for
recording calibration conditions and results.