The acronym PIT Tag stands for “Passive Integrated Transponder” Tag, but what does this really mean?

It all started in 1935 when Scottish physicist Sir Robert Watson-Watt developed a system to warn of approaching planes while they were still miles away.  Since then a lot has changed and allowed researchers to do many great things with RF technology.

For simplicity lets break down the PIT tag into three components:

“P” Passive

This means the transponder does not need a battery.  The transponder gets its power from a larger power coil excites the coil inside the transponder providing enough power to power the circuit that allows the microchip to turn on and broadcast the unique identification information.

“I” Integrated

This is the combination of the microchip, coil, and information in the form of a Unique Identification number programmed onto the microchip inside the transponder.

“T” Transponder

Simply means a device that emits an identifying signal in response to an interrogating received signal.

In basic terms a PIT Tag is short for an implantable transponder used for unique identification of an individual item.  PIT tags are perfectly suited for wildlife such as fish, birds, reptiles, or mammals because of their size, biocompatibility, as well as their frequency that they transmit their information.  In order to transmit through liquid and biological tissue we need a “LF” low frequency gaged in “mHz”. Any higher frequency the transition of the signal is lost in these fluids and It would not be read.

PIT tags are offered in sizes for all species with the standard size being 2.1mm x 12mm.  This provides a perfect size with good read range.
Recently there has been a move to standardize the communication and how the tags “talk” to the readers.  FDX-B is now becoming the standard for this communication protocol.  In the 90’s many companies tried to create “lock” on the transponders by using a propriety protocol.  Good for the manufacture but bad for the researchers.  Standardizing at FDX-B and 134.2 kHz allows for easy and hassle free reading of all microchips.  Being that they will last for 15+ years a standard has to be set.

For questions pertaining to research projects or just information on PIT Tags give UID a call at 1.224.444.8484 or email us at