ES
F. Basan et al.
Table 3 Pistonphone-derived sensitivities and corresponding clip levels for the recorders used in
the HELCOM calibration workshop
Country/
ınstitution Recorder
Sweden/ Soundtrap
FOI ST640HF
Sweden/ Soundtrap
FOI ST300HF
Sweden/ Sylence
FOI LP
Germany/ Sylence
BSH ‚LP
Germany/ | icListen
BSH
Denmark/
AU
Estonia/
TUT
195
190
Hydrophone
HTI-96-UHF
In situ
HTI-92-WB
HTI-96-min
In situ
In situ
HTI-92-WB
Sensitivity
(dB re 1 V/p
Pa)
—171.4
Clip level
(dB re 1 Pa)
171.4
176.8
Frequency of.
pistonphone
ı check (Hz)
250
—176.8
250
-171.6
179.6
1000
— 169.3
177.3
125
171.8
181.3
125
175.9
175.9
250
156.0
164.0
250
Tank calibration
— BSH Sylence — FOI ST300HF
-BSH Sylence (holder) — FO] ST640HF
—- BSH icListen — FO Sylence
‚AU ST600HF — TUT Sylence
185
eo’
L
n 180 F
N
©,
>
@ 1757
S
‘5
170
165
60
277
20h
LT la dr a dpa ng
4000 5000 6000 27000 8000 9000 10000
Frequency [Hz]
Fig. 2 Clip levels from the indoor tank calibration (2-10 kHz), indicating maximum level that can
ve recorded by the different systems before clipping occurs in the data
The two tank runs of BSH’s Sylence LP differed due to mounting. For Sylence LP
recorders, the hydrophone is usually decoupled from the recorder body to minimize
