Transducers Recommended by Garmin
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Winds, Waves, and Bubbles at the Air-Sea Boundary
JEFFREY L. HANSON WINDS, WAVES, AND BUBBLES AT THE AIR-SEA BOUNDARY Subsurface bubbles are now recognized as a dominant acoustic scattering and reverberation mechanism in the upper ocean. A better understanding of the complex mechanisms responsible for subsurface bubbles should lead to an improved prediction capability for underwater sonar. The Applied Physics Laboratory recently conducted a unique experiment to investigate which air-sea descriptors are most important for subsurface bubbles and acoustic scatter. Initial analyses indicate that wind-history variables provide better predictors of subsurface bubble-cloud development than do wave-breaking estimates. The results suggest that a close coupling exists between the wind field and the upper-ocean mixing processes, such as Langmuir circulation, that distribute and organize the bubble populations. INTRODUCTION A multiyear series of experiments, conducted under the that, in the Gulf of Alaska wintertime environment, the auspices of the Navy-sponsored acoustic program, Crit amount of wave-breaking activity may not be an ideal ical Sea Test (CST), I has been under way since 1986 with indicator of deep bubble-cloud formation. Instead, the the charter to investigate environmental, scientific, and penetration of bubbles is more closely tied to short-term technical issues related to the performance of low-fre wind fluctuations, suggesting a close coupling between quency (100-1000 Hz) active acoustics. One key aspect the wind field and upper-ocean mixing processes that of CST is the investigation of acoustic backscatter and distribute and organize the bubble populations within the reverberation from upper-ocean features such as surface mixed layer. waves and bubble clouds. -
Wetsuits Raises the Bar Once Again, in Both Design and Technological Advances
Orca evokes the instinct and prowess of the powerful ruler of the seas. Like the Orca whale, our designs have always been organic, streamlined and in tune with nature. Our latest 2016 collection of wetsuits raises the bar once again, in both design and technological advances. With never before seen 0.88Free technology used on the Alpha, and the ultimate swim assistance WETSUITS provided by the Predator, to a more gender specific 3.8 to suit male and female needs, down to the latest evolution of the ever popular S-series entry-level wetsuit, Orca once again has something to suit every triathlete’s needs when it comes to the swim. 10 11 TRIATHLON Orca know triathletes and we’ve been helping them to conquer the WETSUITS seven seas now for more than twenty years.Our latest collection of wetsuits reflects this legacy of knowledge and offers something for RANGE every level and style of swimmer. Whether you’re a good swimmer looking for ultimate flexibility, a struggling swimmer who needs all the buoyancy they can get, or a weekend warrior just starting out, Orca has you covered. OPENWATER Swimming in the openwater is something that has always drawn those types of swimmers that find that the largest pool is too small for them. However open water swimming is not without it’s own challenges and Orca’s Openwater collection is designed to offer visibility, and so security, to those who want to take on this sport. 016 SWIMRUN The SwimRun endurance race is a growing sport and the wetsuit requirements for these competitors are unique. -
A GUIDE to USING FETS for SENSOR APPLICATIONS by Ron Quan
Three Decades of Quality Through Innovation A GUIDE TO USING FETS FOR SENSOR APPLICATIONS By Ron Quan Linear Integrated Systems • 4042 Clipper Court • Fremont, CA 94538 • Tel: 510 490-9160 • Fax: 510 353-0261 • Email: [email protected] A GUIDE TO USING FETS FOR SENSOR APPLICATIONS many discrete FETs have input capacitances of less than 5 pF. Also, there are few low noise FET input op amps Linear Systems that have equivalent input noise voltages density of less provides a variety of FETs (Field Effect Transistors) than 4 nV/ 퐻푧. However, there are a number of suitable for use in low noise amplifier applications for discrete FETs rated at ≤ 2 nV/ 퐻푧 in terms of equivalent photo diodes, accelerometers, transducers, and other Input noise voltage density. types of sensors. For those op amps that are rated as low noise, normally In particular, low noise JFETs exhibit low input gate the input stages use bipolar transistors that generate currents that are desirable when working with high much greater noise currents at the input terminals than impedance devices at the input or with high value FETs. These noise currents flowing into high impedances feedback resistors (e.g., ≥1MΩ). Operational amplifiers form added (random) noise voltages that are often (op amps) with bipolar transistor input stages have much greater than the equivalent input noise. much higher input noise currents than FETs. One advantage of using discrete FETs is that an op amp In general, many op amps have a combination of higher that is not rated as low noise in terms of input current noise and input capacitance when compared to some can be converted into an amplifier with low input discrete FETs. -
Transducers and Sensors
3/7/2017 TRANSDUCERS AND SENSORS Dr. Ibrahim Al-Naimi Closed‐loop Control System 1 3/7/2017 CHAPTER ONE Introduction Functional Elements of a Measurement System • Basic Functional Elements 1‐Transducer Element 2‐ Signal Conditioning Element 3‐ Data Presentation Element • Auxiliary Functional Elements A‐ Calibration Element B‐ External Power supply 2 3/7/2017 Functional Elements of a Measurement System Transducer and Signal Conditioning 3 3/7/2017 Transducer Element • The Transducer is defined as a device, which when actuated by one form of energy, is capable of converting it to another form of energy. The transduction may be from mechanical, electrical, or optical to any other related form. • The term transducer is used to describe any item which changes information from one form to another. Transducer Element • The Transducer element normally senses the desired input in one physical form and convert it to an output in another physical form. For example, the input variable to the transducer could be pressure, acceleration, or temperature and the output of transducer may be disp lacemen t, voltage, or resitistance change depending on the type of transducer element. 4 3/7/2017 Transducer Element • Single stage • Double stage Single Stage Transducer 5 3/7/2017 Double Stage Transducer Typical Examples of Transducer Elements 6 3/7/2017 Typical Examples of Transducer Elements Typical Examples of Transducer Elements 7 3/7/2017 Transducers classification • Based on power type classification ‐ Active transducer (Diaphragms, Bourdon Tubes, tachometers, piezoelectric, etc…) ‐ Passive transducer (Capacitive, inductive, photo, LVDT, etc…) Transducers classification • Based on the type of output signal ‐ Analogue Transducers (stain gauges, LVDT, etc…) ‐ Digital Transducers (Absolute and incremental encoders) 8 3/7/2017 Transducers classification • Based on the electrical phenomenon or parameter tha t may be chdhanged due to the whole process. -
Transducers in Audio ● Transducer: Any Mechanism That Transforms One Form of Energy Into Another Form of Energy
Transducers in Audio ● Transducer: Any mechanism that transforms one form of energy into another form of energy. ○ Physical energy into mechanical energy ○ Physical energy into electrical energy ○ Mechanical energy into electrical energy ○ Vice versa Audio is primarily concerned with turning physical acoustic energy into electrical energy and back again. What are our two most basic audio transducers? scienceaid.net https://socratic.org/questions/what-part-of-the-ear-contains-the-sensory-receptors-for-hearing From Acoustic to Electric Energy First...a short trip into basic electrical theory... Michael Faraday http://www.rigb.org/our-history/michael-faraday Electro-magnetism Faraday’s Law of Induction: Basically, any change in the magnetic field of a coil of wire will cause a voltage to be induced in a wire. Conversely, any change in the voltage on a coil of wire will cause the magnetic field to change. This is called electromagnetism, and the field created is called an electro-magnetic field. Capacitance When two conductors are given an opposite charge, an electric or more specifically a capacitive field is generated around them. When the relationship between the two conductors (for example the distance between them) changes it causes measurable effects on the charges. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/imgele/cap.png Capacitance When two conductors are given an opposite charge, a electric or more specifically a capacitive field is generated around them. When the relationship between the two conductors, for example the distance between them, changes is causes measurable effects on the charges. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/imgele/cap.png ● Alternating Current (AC) vs Direct Current (DC) ○ AC charge changes from positive to negative across the zero axis. -
Fusion System Components
A Step Change in Military Autonomous Technology Introduction Commercial vs Military AUV operations Typical Military Operation (Man-Portable Class) Fusion System Components User Interface (HMI) Modes of Operation Typical Commercial vs Military AUV (UUV) operations (generalisation) Military Commercial • Intelligence gathering, area survey, reconnaissance, battlespace preparation • Long distance eg pipeline routes, pipeline surveys • Mine countermeasures (MCM), ASW, threat / UXO location and identification • Large areas eg seabed surveys / bathy • Less data, desire for in-mission target recognition and mission adjustment • Large amount of data collected for post-mission analysis • Desire for “hover” ability but often use COTS AUV or adaptations for specific • Predominantly torpedo shaped, require motion to manoeuvre tasks, including hull inspection, payload deployment, sacrificial vehicle • Errors or delays cost money • Errors or delays increase risk • Typical categories: man-portable, lightweight, heavy weight & large vehicle Image courtesy of Subsea Engineering Associates Typical Current Military Operation (Man-Portable Class) Assets Equipment Cost • Survey areas of interest using AUV & identify targets of interest: AUV & Operating Team USD 250k to USD millions • Deploy ROV to perform detailed survey of identified targets: ROV & Operating Team USD 200k to USD 450k • Deploy divers to deal with targets: Dive Team with Nav Aids & USD 25k – USD 100ks Diver Propulsion --------------------------------------------------------------------------------- -
Low-Frequency Active Towed Sonar
LOW-FREQUENCY ACTIVE TOWED SONAR Full-feature, long-range, low-frequency active and passive variable depth sonar (VDS) The Low-Frequency Active Sonar (LFATS) system is used on ships to detect, track and engage all types of submarines. L3Harris specifically designed the system to perform at a lower operating frequency against modern diesel-electric submarine threats. FEATURES > Compact size - LFATS is a small, > Full 360° coverage - a dual parallel array lightweight, air-transportable, ruggedized configuration and advanced signal system processing achieve instantaneous, > Specifically designed for easy unambiguous left/right target installation on small vessels. discrimination. > Configurable - LFATS can operate in a > Space-saving transmitter tow-body stand-alone configuration or be easily configuration - innovative technology integrated into the ship’s combat system. achieves omnidirectional, large aperture acoustic performance in a compact, > Tactical bistatic and multistatic capability sleek tow-body assembly. - a robust infrastructure permits interoperability with the HELRAS > Reverberation suppression - the unique helicopter dipping sonar and all key transmitter design enables forward, aft, sonobuoys. port and starboard directional LFATS has been successfully deployed on transmission. This capability diverts ships as small as 100 tons. > Highly maneuverable - own-ship noise energy concentration away from reduction processing algorithms, coupled shorelines and landmasses, minimizing with compact twin-line receivers, enable reverb and optimizing target detection. short-scope towing for efficient maneuvering, fast deployment and > Sonar performance prediction - a unencumbered operation in shallow key ingredient to mission planning, water. LFATS computes and displays system detection capability based on modeled > Compact Winch and Handling System or measured environmental data. - an ultrastable structure assures safe, reliable operation in heavy seas and permits manual or console-controlled deployment, retrieval and depth- keeping. -
Sonar for Environmental Monitoring of Marine Renewable Energy Technologies
Sonar for environmental monitoring of marine renewable energy technologies FRANCISCO GEMO ALBINO FRANCISCO UURIE 350-16L ISSN 0349-8352 Division of Electricity Department of Engineering Sciences Licentiate Thesis Uppsala, 2016 Abstract Human exploration of the world oceans is ever increasing as conventional in- dustries grow and new industries emerge. A new emerging and fast-growing industry is the marine renewable energy. The last decades have been charac- terized by an accentuated development rate of technologies that can convert the energy contained in stream flows, waves, wind and tides. This growth ben- efits from the fact that society has become notably aware of the well-being of the environment we all live in. This brings a human desire to implement tech- nologies which cope better with the natural environment. Yet, this environ- mental awareness may also pose difficulties in approving new renewable en- ergy projects such as offshore wind, wave and tidal energy farms. Lessons that have been learned is that lack of consistent environmental data can become an impasse when consenting permits for testing and deployments marine renew- able energy technologies. An example is the European Union in which a ma- jority of the member states requires rigorous environmental monitoring pro- grams to be in place when marine renewable energy technologies are commis- sioned and decommissioned. To satisfy such high demands and to simultane- ously boost the marine renewable sector, long-term environmental monitoring framework that gathers multi-variable data are needed to keep providing data to technology developers, operators as well as to the general public. Technol- ogies based on active acoustics might be the most advanced tools to monitor the subsea environment around marine manmade structures especially in murky and deep waters where divining and conventional technologies are both costly and risky. -
Doppler Sonar Current Indicator 8
DOPPLER SONAR CURRENT INDICATOR 8 Model High-performance current indicator displays accurate speed and current data at five depth layers on a 10.4" color TFT or virtually any VGA monitor utilizing a Black Box system www.furuno.com Obtain highly accurate water current measurements using FURUNO’s reliable acoustic technology. The FURUNO CI-68 is a Doppler Sonar Current The absolute movements of tide Indicator designed for various types of fish and measuring layers are displayed in colors. hydrographic survey vessels. The CI-68 displays tide speed and direction at five depth layers and ship’s speed on a high defi- nition 10.4” color LCD. Using this information, you can predict net shape and plan when to throw your net. Tide vector for Layer 1 The CI-68 has a triple-beam emission system for providing highly accurate current measurement. This system greatly reduces the effects of the Tide vector for Layer 2 rolling, pitching and heaving motions, providing a continuous display of tide information. When ground (bottom) reference is not available Tide vector for Layer 3 acoustically in deep water, the CI-68 can provide true tide current information by receiving position and speed data from a GPS navigator and head- ing data from the satellite (GPS) compass SC- 50/110 or gyrocompass. In addition, navigation Tide vector for Layer 4 information, including position, course and ship ’s track, can also be displayed The CI-68 consists of a display unit, processor Tide vector for Layer 5 unit and transducer. The control unit and display unit can be installed separately for flexible instal- lation. -
Basic Physics of Ultrasonographic Imaging
BASIC PHYSICS OF ULTlVlSONOGRAPHIC IMAGING Diagnostic Imaging and Laboratory Technology Essential Health Technologies Health Technology and Pharmaceuticals WORLD HEALTH ORGANIZATION Geneva BASIC PHYSICS OF ULTRASONOGRAPHIC IMAGING Editor Harald Ostensen Author Nimrod M. Tole, Ph.D. Associate Professor of Medical Physics Department of Diagnostic Radiology University of Nairobi WORLD HEALTH ORGANIZATION WHO Library Cataloguing-in-Publication Data Tole, Nimrod M. Basic physics of ultrasonic imaging / by Nimrod M. Tole. 1. Ultrasonography I. Title. ISBN 92 41592990 (NLM classification: WN 208) © World Health Organization 2005 All rights reserved. Publications of the World Health Organization can be obtained from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel: +41 22 791 2476; fax: +41 22791 4857; email: [email protected]). Requests for permission to reproduce or translate WHO publications - whether for sale or for noncommercial distribution - should be addressed to WHO Press, at the above address (fax: +41 22791 4806; email: [email protected]). The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or of certain manufacturers' products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. -
Chapter 1 Introduction to Measurement Systems
4/3/2019 Advanced Measurement Systems and Sensors Dr. Ibrahim Al-Naimi Chapter one Introduction to Measurement Systems 1 4/3/2019 Outlines • Control and measurement systems • Transducer/sensor definition and classifications • Signal conditioning definition and classifications • Units of measurements • Types of errors • Transducer/sensor transfer function • Transducer characteristics • Statistical analysis Closed-loop Control System 2 4/3/2019 Measurement System Transducer and Signal Conditioning 3 4/3/2019 Transducer Element • The Transducer is defined as a device, which when actuated by one form of energy, is capable of converting it to another form of energy. The transduction may be from mechanical, electrical, or optical to any other related form. • The term transducer is used to describe any item which changes information from one form to another. Transducer and Sensor • Transducers are elements that respond to changes in the physical condition of a system and deliver output signals related to the measured, but of a different form and nature. • Sensor is the initial stage in any transducer. • The property of transducer element is affected by the variation of the external physical variable according to unique relationship. 4 4/3/2019 Transducers classification • Based on power type classification - Active transducer (Diaphragms, Bourdon Tubes, tachometers, piezoelectric, etc…) - Passive transducer (Capacitive, inductive, photo, LVDT, etc…) Transducers classification • Based on the type of output signal - Analogue Transducers (stain -
Maximizing Efficiency in Active Loudspeaker Systems
Maximizing Efficiency in Active Loudspeaker Systems Wolfgang Klippel, KLIPPEL GmbH, Dresden, Germany Increasing the efficiency of the electro-acoustical conversion is the key to modern audio devices generating the required sound output with minimum size, weight, cost and energy. There is unused potential for increasing the efficiency of the electro-dynamical transducer by using a nonlinear motor topology, a soft suspension and cultivating the modal resonances in the mechanical and acoustical system. However, transducers optimized for maximum efficiency are more prone to nonlinear and unstable behavior. Nonlinear adaptive control can compensate for the undesired signal distortion, protect the transducer against overload, stabilize the voice coil position and cope with time varying properties of the suspension. The paper discusses the design of modern active systems that combine the new opportunities provided by software algorithms with the optimization of the hardware components in the transducer and power amplifier. reducing power consumption in portable 1 Introduction applications with limited battery capacity. The user of loudspeakers, headphone and other For this discussion, the paper provides new audio devices expects that the audio signal can be definitions of the efficiency to consider the influence reproduced at sufficient amplitude and quality but of the spectral properties of the complex audio prefers products which are smaller, lighter, less cost signals (e.g. music). The paper explains the intensive and provide a longer stand-alone operation difference between efficiency and voltage in personal applications. sensitivity, which is a second important Creating such an audio product requires a characteristic of the transducer required to match the combination of hardware and software components transducer with the power amplifier.