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| Organisation > Facilities |
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| Acoustic Test Facility |
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A state-of-the-art Acoustic Test Facility (ATF) has been set up at NIOT to cater to the needs of testing and calibration of marine instruments of NIOT and other National Research Laboratories, Institutes and Industries. This facility has obtained an ISO/IEC 17025:2005 accreditation from National Accreditation Board for Testing and Calibration Laboratories (NABL) for testing and calibration parameters of underwater acoustic transducers. This facility is used to evaluate acoustic and electrical measurements include spectrum analysis of noise sources and scattering measurements on objects. Acquired data can be processed through various analysis techniques such as FFT and spectrum analysis. It consists of Acoustic Tank, Acoustic Calibration System (ACS) and Acoustic Transducer Positioning System (ATPS). Acoustic transducers are characterized using comparison calibration and reciprocity calibration techniques. |
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This test facility is equipped with a full complement of both digital and analog test equipment, capable of performing the following: |
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Receiving sensitivity |
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Transmitting Voltage/Current Response |
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Impedance/Admittance/Phase vs. Frequency |
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Power / Source level Linearity |
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Transmit and Receive Beam Patterns |
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Frequency Analysis |
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Acoustic tank with Positioning system |
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Reciprocity calibration setup |
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| Services |
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The Acoustic Test Facility, NIOT provides a unique range of facilities and measurement services to meet the individual measurement needs of the customer. |
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ATF, NIOT currently provides the following underwater acoustics calibration and testing services: |
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Free-field calibration of hydrophones by the reciprocity calibration method upto 100 kHz. |
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Free-field calibration of under water acoustic transducers and hydrophones by a comparison method upto 100 kHz. |
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Directional response measurement of hydrophones and transducers in the frequency range upto 100 kHz over 360 degrees of rotation. |
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Transducer electrical impedance / admittance in the frequency range of 100Hz to 1MHz. |
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Power / Source level measurement of transducers. |
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Sound pressure level measurement and frequency analysis |
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Other measurements include, for example, transducer electrical impedance/admittance, directional response/beam patterns of transducers and transducer efficiency. |
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| Quality and Accreditation |
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ATF, NIOT is committed to provide a quality service to all users |
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ATF QUALITY POLICY |
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“ The Acoustic Test Facility at National Institute of Ocean Technology is committed to ensuring accurate, continuous improvement on timely testing and calibration of Acoustic Instruments / Transducers / Parameters to National International Standards. ”
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Accredited Calibration Services (accredited to ISO17025 by NABL) |
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ATF, NIOT currently provides the following underwater acoustics calibration and testing services accredited to ISO17025 : |
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Free-field calibration of hydrophones by the reciprocity from 3 kHz to 100 kHz. |
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Free-field calibration of underwater acoustic transducers and hydrophones by a comparison method from 3 kHz to 100 kHz. |
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Directional response measurement of hydrophones and transducers in the frequency range 3 kHz to 100 MHz over 360 degrees of rotation. |
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Transducer electrical impedance. |
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Power measurement of transducers. |
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| Hyperbaric Test Facility |
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Hyperbaric test facility is used to simulate the pressure in deep sea environment inside a high pressure vessel. The facility has been designed to test components with external pressure up to 90 MPa (900 bar) max., which is approximately equal to 9000 meter of water depth. |
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| This facility is the first of its kind in India. Testing in this facility can save lot of time and money for qualifying underwater components. Which otherwise would have been by actual testing in the sea at that depth. |
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| Technical Specifications: |
1. Working pressure |
: 90 MPa (900 bar) |
2. Inside working diameter |
: 1000 mm |
3. Inside working length |
: 3000 mm |
| 4. Volume |
: 2356 liter |
| 5. Thickness |
: 150 mm |
| 6. Material |
: SA 723 Grade 3 Class 2 |
| 7. Working temperature |
: 4.5 ° - 50 ° C |
| 8. Total weight of the vessel |
: 30 tons. |
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| Main components: |
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High pressure Vessel |
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High pressure pump |
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Valve to control the pressure |
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Hoist system |
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Control system |
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| High pressure Vessel: |
| It consists of a steel cylinder with lids at the top and bottom. Test component is placed inside the pressure vessel. |
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| High pressure Fill & Drain pump: |
| High pressure pump is used to pressurize the vessel up to 900 bar. The system consists out of the intensifier and a high pressure discharge tube. The intensifier is double acting and has an intensifier ratio of 4.16:1 |
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| Water fill and drain is done by gear pump. |
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| Valves: |
| Various valves in the system are used to control the flow, pressure and decompression in system. |
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| Hoist System: |
| Handling of top lid is made easy with the hoist assembly operated by a hydraulic cylinder. |
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| Control system: |
| Touch screen and Programmable logic controller. The various set points and dwell times are entered on the touch screen. |
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| Library |
NIOT’s Library has stated functioning from the year 1995. The main objective of the Library is to help the technical community in solving technical problems and providing technical information to the scientific community. Library is well equipped with modern facilities and resources in the form of books, journals, patents, standards, CD media, handbooks, NHO charts, etc. |
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