RFID Diagnostic Card

Find out frequency and duty cycle of any passive LF/HF reader!

  • Indicates both 125kHz and 13.56MHz fields
  • Determine duty cycle (how often the field is on)
  • Check field strength through LED intensity
  • Fits snugly in any wallet or purse


The RFID Diagnostic Card is a thin, flexible, credit card sized device that can tell you the frequency and duty cycle of any passive low or high frequency RFID or NFC reader, payment terminal, etc. Let’s say your school, office, or apartment building has an RFID reader securing the front door, but you don’t know anything about it. You can easily slap the RFID Diagnostic Card up against it to find out if it’s active, what frequency it’s operating at, and what the duty cycle of the reader is. This tool is designed to easily fit in any card carrier, wallet, or purse, and you can see the frequency indicator LEDs without even having to remove the RDC!

WARNING: Certain Qi wireless chargers which are not implementing the full Qi certified specification can potentially burn out the 125kHz (LF) side of the RDC. Be careful placing the RDC near any wireless charging pads!

Unlike the xLED, the RDC does not give you a good sense of how to position an x-series implant on to an RFID reader or NFC smartphone. If you need to test a reader for the best method to get good reliable reads your x-series chip, definitely check out the xLED.