RFID - Radio Frequency Identification (RFID)

Radio Frequency Identification (RFID) is a generic term that is used to describe a system that transmits the identity (in the form of a unique serial number) of an object or person wirelessly, using radio waves. It's often called auto-identification.

Auto-ID technologies include bar codes, optical character readers and some biometric technologies, such as fingerprint scans. Auto-ID technologies have been used to reduce the amount of time and labour needed to input data manually and to improve data accuracy.

RFID tag

An RFID tag is an object that can be applied to or incorporated into a product for the purpose of identification and tracking using radio waves. A typical RFID tag consists of a microchip attached to a radio antenna mounted within or on some form of housing (typically paper, plastic, metal or glass).

RFID tags are available in all shapes and sizes and can operate in extreme temperature conditions ranging from -40 to 85°C, making them suitable for use in hazardous, rugged, high and low temperature environments. For Oil and Gas plants, ATEX Zone 1 approved intrinsically-safe tags and reading devices are also available. RFID tags can be attached to assets in a variety of ways – adhesive (epoxy resin), screws, rivets, clips, wire or can be welded on.

Types of RFID tag
RFID tags are available in Low Frequency (LF), High Frequency (HF) and Ultra High Frequency (UHF) formats and are suitable for solving a variety of different problems, depending upon the business application:

• LF – no power requirements, little data memory, proof of attendance, maintenance, inspection, field data collection (temperature, pressure), read range of 5-20cm
• HF – some have battery power, increased data storage (2mb); difficult to reach locations, read range of 3 metres
• UHF – require internal power, read range of over 10 metres and best suited for warehouse and inventory management

Types of Low Frequency RFID tags

42 mm weld-on tag

12mm adhesive tag

Coin tag

Key fob tag

Intrinsically safe tag

Glass tag

RFID reader

To retrieve the data stored on an RFID tag, you need a reader. A typical reader is a device that has one or more antennas that emit radio waves and receive signals back from the tag. The reader then passes the information in digital form to a computer application. These readers can be fully integrated within handheld computers as shown below:

Examples of RFID readers