4 – Appendix
4.1 Connector
Wiring
Wiring tables for the deck and tow cables are included on the serialized CD included with
each shipment. Channel 1 is always wired as the first hydrophone/hydrophone group in
the active section.
Figure 10 shows the battery pack-to-streamer wiring.
Figure 10. DHA-7/MicroEel-D Battery Pack wiring.
4.2 Calibration
All hydrophone channels of any given streamer have been low-frequency calibrated over
a band from 0 to 200 Hz as a quality control measurement. The performance band
defined by the low-cut of the polymer film capacitance and input resistance of 10 Hz, and
a high-cut of 10 kHz has been demonstrated to be “predictably flat” over a entire band.
Significant testing has demonstrated that the low frequency calibration of the hydrophone
is 99.99% representative of the broadband response up to 10 kHz. This low frequency
calibration is performed by the substitution method where a known calibrated reference is
compared with the unknown hydrophone channel under calibration. The calibrated
reference and the unknown are placed in a sealed chamber into which white noise is
injected. A dual channel FFT analyzer is used to compare the response of the two and the
resulting transfer function indicates the response in dB of the unknown in terms of
sensitivity relative to 1V per µPa and phase.
All hydrophone channels in the streamer are guaranteed to be within a ±1 dB relative
span. The calibration plots for each hydrophone are provided on the serialized CD
included with each shipment.
MicroEel Solid Analog Streamer Operation Manual
Page 16 of 18
Rev. C 050612 du
