Radio Frequency Identification (RFID): Definitions
(some of the of terms used in RFID technology)
Some libraries use sensors at their exits in order to make sure that no one is taking materials away without making proper check outs.2. Any detection instrument that is used to determine temperature, moisture, radiation, light, distance, or motion: There are all kinds of sensors which are being utilized to gain information that is essential for the well-being of humanity.
Water absorbs UHF energy, causing signal attenuation.
There are different methods of singulation, but the most common is "tree walking", which involves asking all tags with a serial number that starts with either a "1" or "0" to respond.
If more than one responds, the reader might ask for all tags with a serial number that starts with "01" to respond, and then "010". It keeps doing this until it finds the tag it is looking for.
It's considered "smart" because it can store information; such as, a unique serial number and it can communicate with a reader.
Variations in the reflected signal can be used to provide a unique identity.
When tags enter the reader's field, they immediately communicate their presence by reflecting back a signal.
This is useful when you want to know everything that is passing a reader; such as, when items are moving quickly on a conveyor.
In other cases, the reader wants to simply find specific tags in a field, in which case it wants to broadcast a signal and have only certain tags respond.
Algorithms are used to make sure the readers attempt to read tags at different times.
Injectable ID chip or biochip transponders
Biochip transponders are electronic devices that are inserted under the skin of an animal to provide it with a unique identification number.
Injectable ID transponders are less painful, faster to implement, and more cost-effective than ear-tags, brands, or tattoos, have been used to identify livestock animals; such as, pigs, sheep, cows, and horses for several years.
Once inserted under an animal's skin the transponder remains inactive until read by a compatible scanner.
The scanner works by sending a low frequency radio signal to "wake up" the transponder and provide it with the power it needs to send its unique identification code back to the scanner where it is read, compared to other codes in the database so it can positively identify each animal.
Here is a List of Radio Frequency Identification articles for further explanations: RFID
They can send information faster and farther than high-frequency and low-frequency tags, but radio waves don’t pass through items with high water content; such as, fruit, at these frequencies.
UHF tags are also more expensive than low-frequency tags, and they use more power.