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The DAQChannel

September 2009

Measuring with electrical sensors is so… passe! The new kids on the block: optical sensors. These come in many forms, shapes and form factors, and are mostly derived from the telecom boom in the late nineties. There is more and more interest for this type of sensor, especially in the area of structural monitoring.


There are two groups of optical sensors: instrinsic and extrinsic. Intrinsic optical sensors change the property of light within the fiber itself, while extrinsic optical sensors change the property of light outside the fiber. An example of extrinsic optical sensor is a simple on/off light detector, which outputs a digital ‘1′ when there is light and a ‘0′ when light is not present. Extrinsic sensors are often used in security systems, toys and more.


Intrinsic optical sensors are not quite as common as extrinsic sensors. An example is Fiber Bragg grating (FBG) sensors. FBG sensors are created by “etching” periodic variation of refractive index to create a mirror that only reflects a certain frequency of light, or commonly known as color. As the fiber expands/contracts due to strain or temperature variations, the color reflected by the FBG changes.


The optical fiber with embedded sensors can be seen mounted on the wing

The optical fiber with embedded sensors can be seen mounted on the wing.




Optical strain gauges are being evaluated and used by NASA, and you can see them mounted on an aircraft wing. They are also used by civil engineers in structural monitoring for buildings and bridges.


Engineers and scientists are now starting to see value in optical sensing and instead of adapting telecom technologies for sensing, are designing new innovative products and solutions tailored for measurement applications.


What are the advantages over electrical sensors you ask? It’s immune to corrosion, electro-magnetic inteference and lightning, it allows for many sensors on one single fiber, and requires no calibration. It’s a dream come true! – Nathan




So you probably have heard about USB 3.0, the faster, better, next generation USB. In fact, its name also points to the improvement in speed: USB 2.0 was called hi-speed USB, and now the new USB 3.0 is called Superspeed. Clever, no? USB 3.0 has been in the news for 2 years now, with nothing to show.


Well, it's quickly becoming a reality. Just recently, the USB-IF organization created a peripheral development kit, which includes two PCIe extensible host controller interface (xHCI) for USB 3.0, a USB 3.0 cable, and some documentation. This kit will give USB 3.0 device developers something they can develop on.


The added speed will give you capabilities for applications like USB 3.0 Blueray, and be very useful for high-performance, synchronized and simultaneous data acquisition.


So keep your eyes peeled, it's coming to a PC near you!

USB 3.0 Development Kit


FPS with Real Guns

Posted by JenniferW Sep 8, 2009

Okay, this is one is a little crazy: these guys are playing Half-Life, with real guns. Is it necessary? No. Is it cool? Hell yeah!  This is how they did it: they projected a first person shooter (FPS) game on a dry wall with 4 mounted accelerometers. Using the vibration measurements and graphical software, they were able to determine where exactly the bullet landed, and feed the coordinates to the host PC, where it converts it into a shot in the videogame. The key DAQ ingredient for this? Tightly synchronized, simultaneous 24-bit ADCs.




Member since: May 11, 2009

We are a group of engineers passionate about data acquisition (DAQ), sensor measurements, and I/O. We strive to provide relevant news and information on new technologies, cool applications, tutorials, and more.

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