In the first part of our introduction to RFID, we take a look at its uses and the part it has played in industry since its conception in the 1940s.
For many of us, using a key to start a car, a card to access a building and validating a bus or underground ticket have become part of our daily routine. Without always realising it, we are using automatic data capture technology that relies on radio-frequency electromagnetic fields. This technology is known as Radio-Frequency Identification, or RFID.
How is RFID used?
Just as people use RFID when going about their daily lives, industry also use this technology as part of a predictive maintenance programme. Predictive maintenance (PdM) programmes are designed to help determine the condition of in-service equipment in order to predict when maintenance should be performed. This approach promises cost savings over routine or time-based preventive maintenance, because tasks are performed only when warranted.
RFID (Radio Frequency Identification) can be defined as follows: automatic identification technology which uses radio-frequency electromagnetic fields to identify objects carrying tags when they come close to a reader. However, RFID cannot be reduced to one technology. RFID uses several radio frequencies and many types of tag exist with different communication methods and power supply sources.
RFID tags generally feature an electronic chip with an antenna in order to pass information onto the interrogator (also known as a reader). The assembly is called an inlay and is then packaged in various forms to be able to withstand the conditions in which it will operate. This finished product is known as a tag, label or transponder. The information contained within an RFID tag is a unique identifier, once this identifier has been written into the electronic circuit, it can no longer be modified, only read. This principle is called WORM Write Once Read Multiple.
The History of RFID
RFID was first used during World War II to identify aeroplanes (IFF: Identify Friendly Foe). The objective was to use the aeroplane’s radar signal to read an identification number in order to identify whether they were allies or enemies.
During the 1960-70s, RFID systems were still considered a secret technology used by the army to control access into sensitive areas (nuclear plants etc.).
Technological developments lead to the creation of passive tags.
This technology meant we no longer needed the energy to be embedded into the tag. Therefore the price of the tag and its maintenance could be significantly reduced.
Standardisation for the interoperability of RFID equipment began.
The Massachusetts Institute of Technology (MIT) created the Auto-ID center – a research center specialised in automatic identification (including RFID).
The MIT Auto-ID center became the global EPC, an organism in charge of promoting the EPC (Electronic Product Code) standard.
RFID technologies are now widely used in almost all industrial sectors, such as aerospace, automotive, logistics, transport, health, life and hazardous areas. ISO (International Standard Organization) took part in establishing technical and applicative standards that let to have a high degree of interoperability or interchangeability.
Active and passive RFID tags
- Passive RFID tags: Passive tags only backscatter magnetic or electromagnetic waves coming from the interrogator. That is the only way they can communicate with the interrogator. In other words, they do not have any RF emitters on board so they cannot create their own RF signals.
- Semi-Passive RFID tags: Battery assisted passive (BAP) tags have an embedded battery (rechargeable or not) to supply internal circuitry or connected sensors or actuators. This power source is not used the create any RF signal as the tag is always passive (backscatter only incoming RF signal from interrogator).
- Active tags: active tags have their own RF emitter on board. They can either send RF signals to the interrogator as they receive a comprehensive command or function without any external command (they act as a RF beacon). As creating an RF signal requires a lot of energy, active tags quite often have an internal (embedded) power supply. This means they are often confused with battery assisted tags.
RFID tags: the different classes
There are 6 classes of RFID tag:
- Class 0 and Class 1: Read-only passive tags
- Class 2: Passive tags with additional functionality
- Class 3: Semi-passive RFID tags
- Class 4: Active tags with broad-band peer-to-peer communication
- Class 5: Readers – powers Classes 1, 2 and 3 tags and communicates with Classes 4 and 5.
Now that you’ve learned about RFID, how it works and is utilised in a multitude of sectors, we’ll be going more in-depth in our next blog, covering TTF and ITF protocol.
Compatibility with CorDEX products
The IW Series SMART IR Windows incorporates an embedded RFID tag, and can communicate wirelessly with any suitably RFID enabled device by providing a unique serial number wirelessly. The UT5000 is a next generation thickness gauge packed with proven technologies: CorDEX CONNECT™ uses RFID + Software to tag measurements with their location then organises the data, giving the engineer a view of the pipeline at any specific location.
Want to know more?
If you’d like more information on industry topics such as RFID, as well as our infrared and intrinsically safe products, visit our KnowledgeHub for the latest eBooks and blogs. You can also contact us on +44 (0) 1642 454373 from the UK or +1 877 836 0764 in the US.
In the meantime, why not download our FREE eBook on ‘Ultrasonic Thickness Gauges in Potentially Hazardous Environments’.
Inaccuracies Introduced Using Infrared Windows and Cameras With increased focus on electrical safety and the widespread adoption by industry of NFPA-70E, infrared systems are increasingly becoming more popular. Download our FREE white paper now exploring inaccuracies in predicative maintenance.
Inaccuracies Introduced Using Infrared Windows and Cameras
With increased focus on electrical safety and the widespread adoption by industry of NFPA-70E, infrared systems are increasingly becoming more popular. Download our FREE white paper now exploring inaccuracies in predicative maintenance.