Transponders

It is another smart device of object identification. It is an instrument anchored to any device, that receives an acoustic signal at a certain frequency (frequency is number of wavelengths that pass a fixed point per second) and transmits a response at a different frequency. In the illustration in Figure, transponders are anchored along the top of the ridge & spaced at even intervals.

                                                                    Figure: Transponders

Basically, transponder is a device which works on the RF (Radio frequency) principle. The chip utilized in such device might handle hundreds of bytes of information. A radio signal at specific assembly stations causes the transponders to emit information that might be decoded by a local receiver. Some smart transponders have read/write capacity, permitting user to support decision-making. But cost incurred while utilizing transponders is very high, therefore its uses are restricted in space works, shipping industry, etc.