Installation manual

Final tests and measurements
143
851-164574 / C
11.3 Receiving voltage response (VR)
Preparations
In order to measure the receiving voltage response, use the test
hydrophone in the same position as for the previous source level
measurements.
Use the following menu settings on the sonar.
1 Select the Setup menu.
2 Push the Test... button to access the System Test menu.
3 Push the Te st Co nf ig button, and observe the Te s t C o nf ig
submenu appear at the bottom of the menu field.
4 Select Noise & VR to select the menu settings for the
receiving voltage response.
All the required sonar parameters for the voltage response
measurements have now been set automatically.
Procedure
Observe the following procedure to measure the receiving voltage
response. Note that the procedure calls for an oscilloscope and a
test oscillator.
1 Check that the bearing and tilt angle values are the same as
for the source level measurements.
→ Refer to table 4 on page 141.
2 Observe the Echo Level readout in the System test menu.
- This is the echo level which - without a signal oscillator
connected - is the noise level for the selected bearing. The
current value is shown on the Echo level button.
3 Enter the Echo level value into the cell for Noise level in the
Measurement and calculation results table.
→ Refer to table 6.
4 Connect a signal oscillator to the hydrophone.
5 Adjust the oscillator frequency to 26.0 kHz.
6 Connect the oscilloscope channel to measure the output
voltage to the hydrophone.
7 Adjust the oscillator voltage until the Echo level readout is
0.0 dB.