Ocean Instruments SoundTrap ST640, Руководство пользователя

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as 2.0 V.
PAMGuide
PAMGuide provides several convenient calibration schemes. For SoundTrap data select the end-
toend calibration type and enter a system sensitivity of the calibration value * -1.0 (eg -176.0).
Audacity
Audacity reports SPL in units of dB re full scale. To scale SoundTrap data use the following:
Value in dB re 1 uPa = audacity value + end-to-end calibration – 3dB;
For example, if the end-to-end value from the calibration sheet is 176.0 dB, and audacity reports a
level of -70 dB, the calibrated SPL is 103.0 dB re 1 uPa.
Calibration Tones
By default, a series of calibration tones will be audible at the beginning of each recording. These can
be used to check the calibration of the recording. After applying the calibration to a recording, the
SPL of the 1 kHz tone should be equal to the calibration tone level stated on the calibration sheet.
If the calibration tones are an annoyance, they can be disabled on the deploy tab. However, we
recommend keeping them enabled where possible as they provide a useful check of system
calibration and performance.
ST640 Calibration
ST640 recorders have a fixed gain of -4dB. Overall system calibration is determined by the
hydrophone used. This is calculated by adding recorder gain to the hydrophone calibration. For
example, using a hydrophone with a sensitivity of 177 dB re 1uPa will result in an overall system
calibration of 173 dB. This is the SPL that will result in a normalised (±1.0) wav file with a full-scale
signal ie 2.0 units peak to peak. This can be applied to data using the application examples above.
4 Appendices