|MadSci Network: Engineering|
Try this site: http://omega.com/ You can link to their site on pressure transducers, and use their technical reference section to see how pressure transducers work. In choosing a transducer, I am assuming you want pressure in a gas. Liquids a more difficult, but the Omega references can help you there. Pressure System International units are Pascals (Pa). English system units are pounds/square inch (psi). In choosing a transducer, you must select an input pressure range, like 0 - 200 psi. Range is just the lowest and the highest pressure you anticipate measuring. You must also choose what kind of output you want. I like the self- contained units that will give DC volts out for pressure in. Finally, you choose one that can be powered adequately and survive the environment you wish to place it in. Companies like Omega have "applications engineers" that help customers in choosing a product that will meet their needs. Here is another manufacturer's pressure transducer selection guide: http://www.barksdale.com/products/trans/selecttrans.html What is inside a pressure transducer? Often its a plate pushing on a strain gage bridge that creates an unbalance voltage that other circuitry amplifies. But this is only one technique among many. Larry Skarin
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