25-06-2013, 03:28 PM
Transducer
Transduce.ppt (Size: 258 KB / Downloads: 499)
Classification of transducers
Based on principle of transduction
Active & passive
Analog & digital
Inverse transducer
Based on principle used
Thermo electric
Magneto resistive
Electro kinetic
Optical
Passive transducer
Device which derive power reqd. for transduction from auxiliary power source
- externally powered
Eg : resistive, inductive, capacitive
Without power they will not work
Active transducer
No extra power reqd. to produce I/p
Self generating
Draw power from input applied
Eg. Piezo electric x’tal used for accelartion measurement
Diaphragm
Common pressure sensing elastic element
Thin circular plate stretched & fastened at its periphery
Made of elastic alloys of bronze,phosphor bronze, stainless steel or alloys like Monel, Nickel span -C
Capsule
Two corrugated metal diaphragms sealed together at periphery
Forms a shell like structure
One diaphragm has a port at centre to admit pressure to be measured
Other diaphragm linked to a moveable mechanical part.