Page 1
Hydrophone
Type 8011
User’s Manual
Page 2
Hydrophone
Type 8011
Technical Description . . . . . . . . . . . . . . . . . . . . . . . Page 2
Full Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . Page 3
Using the Hydrophone . . . . . . . . . . . . . . . . . . . . . . . Page 5
Care of the Hydrophone . . . . . . . . . . . . . . . . . . . . . Page 7
Service and Repair . . . . . . . . . . . . . . . . . . . . . . . . . Page 8
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8
CE Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8
Contents
User’s Manual
Page 3
The cartridge
The Hydrophone uses a piezoelectric crystal sensing element, which is
enclosed in a capsule so that it can withstand high pressure encountered
at depths of up to 50m without being damaged or suffering changes in its
performance characteristics. The sensing element gives the Hydrophone a
dynamic range of more than 100dB, so that even large fluctuations in the
SPL emitted from a sound source, or in the distance from the sound source
to the Hydrophone, will cause no distortion in the recorded audio signal.
The cable
The Hydrophone uses an integral cable with a robust and abrasion resistant
polyurethane jacket. The choice of materials allows the product to be used in
permanent installations immersed in water or ice over longer periods of time
without damaging the product or changing its specifications.
The preamplifier
The Type 8011 uses a built-in precision preamplifier, which remains
unaffected by temperature changes. The preamplifier is powered via a
standard P48 system and is equipped with a standard 3-pin XLR-connector
(see Fig. 1 for pin designation).
Important: For the Hydrophone to meet its specifications it must be
powered correctly.
2
Technical Description
User’s Manual
Fig. 1. External view of the
output socket of the Type 8011.
Page 4
Cartridge type: Piezoelectric sensing element
Principle of operation: Pressure
Power Supply: 48 V Phantom
Frequency range: 100Hz - 20kHz ±3dB
Directional characteristics: Omnidirectional
Sensitivity: Nominally 0.7mV/Pa ±2dB
Equivalent noise level A-weighted: Typ. <8µV
Max SPL: 162dB SPL peak
Output impedance: <300 Ohm
Polarity: Positively increasing sound pressure produces positive-going voltage
at pin 2. Pin 1: Ground, Pin 2: Signal +, Pin 3: Signal return
Operating temperature range: -10° to +50° C (+14° to 122°F)
Dimensions: Microphone length: 150mm (5.7in); Capsule diameter: 32mm (1.2in)
Weight: 500g (1.1lbs) (incl. cable)
Frequency Response
Typical on-axis reponse in water.
3
Full Specifications
User’s Manual
Br el & Kj r
Measuring Obj.
QP 1124 Multiply Freq. Scale by
A B C Lin.
Zero Level:
(1612/2112)
Potentiometer Range:
dB Rectifier: Lower Lim. Freq.: Hz Wr. Speed: mm/sec. Paper Speed: mm/sec.
Rec. No.:
Date:
Sign:
dB
10
0
Hz100 200 500 1 kHz 2 5 10 20 kHz
-10
-20
-30
94005e
Page 5
0 dB
10 dB
20 dB
30 dB
40 dB
Polar pattern
Directional characteristics of Hydrophone Type 8011 at 10kHz.
4
Full Specifications
User’s Manual
Page 6
Using the Hydrophone
To ensure optimal results, certain steps must be taken to prepare the
Hydrophone for use, bearing in mind any possible adverse effects of the
environment or medium in which it will be immersed. Please read the
important tips and precautions below.
Important: The 3-pin XLR connector is not waterproof. Do not immerge the
XLR connector in water and keep it dry at all times.
Important: The water medium often has a different electrical potential than
the ground potential of the electrical equipment. This phenomenon might
cause unwanted noises and hum in the Hydrophone. In order to prevent
these noises from occurring on the recording, the water medium must be
properly connected to the chassis ground of the electrical equipment in use.
A cobber wire immersed in the water and connected to the chassis ground
will solve the problem.
Important: Many small air bubbles covering the element can affect the
sensitivity of the sensing element. The element must be in full contact with
the medium in order to meet the specifications. A wetting agent such as liquid
soap can be applied to ensure that bubbles do not adhere to the surface of the
Hydrophone. Clean the Hydrophone carefully before and after use.
Important: The Hydrophone is supplied with a 10 meter (30ft) long special
quality cable as standard. It is not possible to extend existing cables.
Hydrophones with longer cables can be ordered on special request.
5
Using the Hydrophone
User’s Manual
Page 7
Stereo recording in water
Due to the omnidirectional pick-up pattern of the Hydrophone it is possible
to record A-B stereo using two 8011 Hydrophones. The spacing between the
two Hydrophones needs to be 4 times larger (approx. 1-2 meters) than when
making A-B stereo recording in air. This is due to the fact that wavelengths
are 4-5 times longer in water than in air. Please see the table below.
Speed of sound in water
6
Using the Hydrophone
User’s Manual
Page 8
Wavelengths in water
Care of the Hydrophone
The Type 8011 Hydrophone from DPA Microphones is covered by a polyurethane
seal on both the sensing element and on the cable. Polyurethane is quite resistant
to salt-water and does not require any additional coating. Keep the Hydrophone
dry and clean when not in use. Do not put a wet Hydrophone in the carrying case.
7
Care of the Hydrophone
User’s Manual
16
20
25
31.5
40
50
63
80
100
125
160
200
250
315
400
500
600
800
1000
1250
1600
2000
2500
3150
4000
5000
6300
8000
10000
12500
16000
20000
21.4
17.2
13.7
10.9
8.58
6.86
5.44
4.29
3.43
2.74
2.14
1.72
1.37
1.09
85.8 cm
68.6 cm
57.2 cm
42.9 cm
34.3 cm
27.4 cm
21.4 cm
17.2 cm
13.7 cm
10.9 cm
8.58 cm
6.86 cm
5.44 cm
4.29 cm
3.43 cm
2.74 cm
2.14 cm
1.72 cm
Wavelengths in air
(20∞C)
[m]
Frequency
(1/3 octave)
[Hz]
Wavelengths in salt water
(20∞C)
[m]
97.4
77.9
62.3
49.5
39.0
31.2
24.7
19.5
15.6
12.5
9.74
7.79
6.23
4.95
3.90
3.12
2.47
1.95
1.56
1.25
97.4 cm
77.9 cm
62.3 cm
49.5 cm
39.0 cm
31.2 cm
24.7 cm
19.5 cm
15.6 cm
12.5 cm
9.74 cm
7.79 cm
Page 9
Service & Repair
Products from DPA Microphones are extremely stable and there should not be
any significant change in the specifications with time and use. If you are not
totally satisfied with the characteristics exhibited by these products, please
contact the nearest DPA Microphones representative for further details of the
service and repair facilities available.
Note: Due to the special construction of the Hydrophone, service and repair in
the event of faults or defects, can only be offered on the cable and connector.
DPA Microphones has a maximum seven working days in-house service policy, usually ensuring that no more than seven working days will elapse from
the day the item is received and accepted to the day we are ready to return
it to you. Your satisfaction is our satisfaction.
Please contact DPA Microphones for your nearest representative on
tel. +45 48 14 28 28 or fax +45 48 14 27 00. You can also get in touch with
DPA Microphones via the internet using e-mail: info@dpamicrophones.com
or by visiting www.dpamicrophones.com.
Warranty
All products from DPA Microphones are covered by a one-year limited
warranty on both mechanical functionality and documented specifications.
In case of a warranty claim, your invoice is your warranty registration.
CE Standard
The CE-mark guarantees that all products conform to relevant standards
approved by the European Community. The products described in this User’s
Manual comply with current relevant standards when used with cables from
DPA Microphones.
EMC Directive: 89/336/EEC, amended by 92/31/EEC and 93/68/EEC
Low Voltage Directive: 73/23/EEC, amended by 93/68/EEC
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Service & Repair
User’s Manual
Page 10
Gydevang 42- 44 • 3450 Alleroed • Denmark
tel: +45 48 14 28 28 Fax: +45 48 14 27 00
email: info@dpamicrophones.com
www.dpamicrophones.com
DPI8011
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