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Sensors Provide Early Diagnosis Of Microcracks In Aircraft |
 Today's aircraft are in service virtually around the clock and must operate reliably and safely at all times. An active sensor system helps to detect concealed fatigue cracks in aircraft bodies, thus reducing maintenance times considerably.
If a tiny crack in the hull of an aircraft remains undetected for a long time, it can easily spread and put passengers’ lives at risk. Each component is therefore subject to international maintenance regulations: Aircraft bodies must be thoroughly inspected every 15 to 18 months, depending on the type of plane. This often requires the technicians to dismantle an aircraft’s interior lining – an expensive and time-consuming process involving several days of downtime in the hangar. Researchers at the Fraunhofer Institute for Structural Durability and System Reliability LBF in Darmstadt are developing a sensor system that allows engineers to continuously monitor the condition of their aircraft and detect any damage at an early stage.
The system is based on piezoceramic sensors that are attached to the aircraft body in a network pattern. What is special about these sensors is that they start to oscillate when a voltage is applied to them – and when they are subjected to pressure, they generate voltage. The scientists make use of both effects: While the piezo foils cause part of the hull to oscillate, the others measure the component’s response to this stimulation. “We investigated the oscillation behavior of damaged struts and rivets in an aircraft body and compared it with that of intact parts,” explains LBF project manager Dirk Mayer. “If a component is defective, it oscillates at a different frequency from one that is intact when stimulated by the piezoceramics – just as a cracked glass sounds different from an undamaged one when you tap it with your fingernail.” In this way, the researchers can accurately track down faults and monitor their development – be it fatigue cracks in the hull and wings, or rivets and other joining parts coming loose. This form of observation is also referred to as ‘structural health monitoring’ (SHM).
“With the help of this system, any damage behind the lining or in difficult-to-reach places can be identified quickly and easily, thus reducing maintenance times and inspection costs,” says Mayer. The researchers have already performed tests on a hull component in the laboratory, and are now implementing the new technology with standardized piezo and electronic components. The system will then also be suitable for use in vehicle manufacture or engine and plant construction.
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Dear Editor,
I hope you can help me or at least point me in the right direction. My neighbor just put up a huge CB Radio antennea, the thing is higher that the roof of his home, the problem is, now I have interference through our television set speakers. We can hear him speaking although it is not too clear. How can I fix the problem so that we can watch t.v. without hearing this noise? Any help you can give me would be greatly appreciated.
Sincerly,
Donna R.
Dear Donna,
If your neighbor's transmissions are interfering with your TV, the best thing for you to do is complain to the Federal Communications Commission. The FCC investigates cases of interference and they will determine if your neighbor's transmissions contain out-of-band signals. You might also try talking to your neighbor. If his antenna is for amateur radio rather than Citizens Band, "ham" radio operators have a policy of supplying a free filter for your TV in such cases.
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ElectronicDesignNet News
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We scan the wires, web sites, blogs and news media for the most interesting and relevant information, then summarize it for you in a convenient format, organized by topic areas during the week:
You can stay on top of things without wasting your precious time sifting through lots of noise. Subscribe to our digest and receive it in your eMail, or come to our site and read it in your web browser. Digest eMail subscriptions can be managed on the Newsletters tab of the "My Settings - Edit Profile" page once you register.
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IFM Offers Fast-Acting Temperature Sensor |
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Product Showcase - Friday
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Thursday, 10 May 2007 |
Reaction times as quick as one second are characteristic of the TA3 range of temperature sensors from ifm electronic. Suiting use in oil or hydraulic lines on stationary applications but also in mobile vehicles and in small pipes where space is limited, the TA3 utilises high-precision class A Pt elements for temperatures ranges between 0...140°C or -10...150°C. The response time of the sensors is 1 s for T05 and 3 s for T09....more  (0) Comments |
Raytek Fields IR Temperature Sensors |
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Product Showcase - Friday
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Thursday, 10 May 2007 |
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The Raytek Marathon MM Series, which covers a temperature range of minus 40 to 3000°C (minus 40 to 5432°F), consists of six IR temperature sensor models, each with a specific measurement wavelength and temperature range appropriate for either low- (minus 40 to 800°C / minus 40 to 1472°F), medium- (250 to 1100°C / 482 to 2012°F), or high-temperature (300 to 3000°C / 572 to 3273°F) production monitoring....more (0) Comments |
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MicroStrain Announces 6X speed Improvement For All 2.4GHz Wireless Sensor Nodes |
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Product Showcase - Friday
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Thursday, 10 May 2007 |
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MicroStrain has released the latest version of its Agile-Link wireless nodes which feature real-time streaming rates up to 4 kHz. This is a significant increase in sample rate, which opens up many new applications for wireless sensor networks. The Agile-Link nodes which support high-speed streaming rates are: G-Link wireless triaxial accelerometer node, V-Link wireless voltage node and SG-Link wireless strain gauge node....more (0) Comments |
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Measurement Specialties Rotary Magnetic Encoders Offer Improved Performance |
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Product Showcase - Friday
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Thursday, 10 May 2007 |
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The ED Series of magnetic encoders by Measurement Specialties provides a platform for traditional optical encoder and potentiometer replacement with several significant improvements over existing electro-mechanical designs. The advantages inherent in magneto-resistive (MR) technology enable more robust sensor system designs offering lower total cost....more (0) Comments |
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