Stories
Slash Boxes
Comments

SoylentNews is people

posted by Fnord666 on Wednesday May 03 2017, @10:37AM   Printer-friendly
from the hot-topic dept.

Technical systems must be regularly checked for defects, such as cracks. Up to now, piezo sensors measuring pressure, force or voltage have been used to reliably detect such faults – but only to around 200 degrees Celsius. Now, special high-temperature piezo sensors can continuously monitor components that are as hot as 900 degrees Celsius. Fraunhofer researchers will present their development at the SENSOR+TEST measurement fair in Nürnberg, May 30 to June 1, 2017.

If a component such as a steam pipe in a coal-fired power station has a crack, corrosion or other flaw, repairing it is imperative. Ultrasonic sensors mounted externally can detect flaws like these, but only when the component does not heat up to more than around 200 degrees Celsius. Above that temperature, conventional piezoelectric materials can no longer determine pressure, force, voltage or acceleration or act as a gas sensor. Furthermore, at these temperatures any plastic encapsulations that are not heat-resistant will fail.

Researchers at the Fraunhofer Institute for Silicate Research ISC have now successfully realized piezo sensors for high-temperature applications. "We have already implemented our sensors at temperatures of up to 600 degrees Celsius. Generally speaking, temperatures of up to 900 degrees Celsius are possible," says Dr. Bernhard Brunner, head of the Application Technology department at Fraunhofer ISC's Center Smart Materials. Additionally, the ultrasonic sensors remain stable over long periods – at least two years in any use case – and for many applications, researchers expect a service life of several decades. The principle is the same as for other piezo sensors: they are mounted externally on the component, for instance on a hot steel pipe. When an alternating voltage is applied to the piezoelectric crystal, it mechanically deforms and sends an ultrasonic wave into the material. After the sound wave, the sensor switches to receive and detects the signal reflected by the component. In most cases, it receives the same original signal it sent. However, if the component is cracked or has a corroded spot, the defect alters the reflected signal and indicates the defect's location. When several transducers are used that serve as transmitter and receiver, the location of the flaw can be pinpointed exactly to within a few millimeters. Depending on the component's material, the sensor's range covers a few meters.


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 2) by VLM on Wednesday May 03 2017, @01:58PM (3 children)

    by VLM (445) Subscriber Badge on Wednesday May 03 2017, @01:58PM (#503629)

    Thermal electric power plants used to be too hot for ultrasound transducers. Now they're cool. Nuclear reactors, of course, have always been cool.

    Starting Score:    1  point
    Karma-Bonus Modifier   +1  

    Total Score:   2  
  • (Score: 2) by bob_super on Wednesday May 03 2017, @06:04PM (2 children)

    by bob_super (1357) on Wednesday May 03 2017, @06:04PM (#503804)

    Nuclear reactors act cool, because it's critical that they keep it all inside, otherwise it's all over the waves, the press core blows up, and that just throws a cloud over the whole family.

    • (Score: 2) by VLM on Wednesday May 03 2017, @07:09PM (1 child)

      by VLM (445) Subscriber Badge on Wednesday May 03 2017, @07:09PM (#503864)

      the press core blows up, and that just throws a cloud over the whole family.

      Yeah the priest had some marriage line about "let no man separate what has been joined" but clearly they don't weld like that on the Japanese Tsunami coast and now they're only staying together for the sake of their radioisotope daughters running around on the beach bare and uncontained for the whole world to see, nothing covering up anything, for shame for shame that's just not going to end well. Some of the radioisotope daughters already have radioisotope daughters of their own, requiring massive government funding of course. Needless to say they randomly bond with any organic molecule that floats by and sticks out his electron, totally degenerate. At least the employees wear protection, not like the Russians in the 80s at Chernobyl. What a mess. If even the Japanese, of all races, can't keep their radioisotope daughters under civilized reasonable control I don't think any other civilization really has a chance. Maybe Islam's got it right after all, keep your radioisotope daughters wrapped up away from the public eye, and just burn oil for energy, that's safer, well, plus or minus BP offshore gas wells in the gulf of Mexico, etc. Ah theres no easy answers...

      • (Score: 2) by bob_super on Wednesday May 03 2017, @07:44PM

        by bob_super (1357) on Wednesday May 03 2017, @07:44PM (#503889)

        > totally degenerate

        It's the decay of the nuclear family ...