Will Mobile Phones Demagnetize RFID Bus Cards?

A: "I can't swipe my bus card anymore"

B: "Is it out of magnetism?"

I believe everyone often hears this kind of conversation when they often use RFID cards in their daily lives, but is it really because your bus card is "out of magnetism" that you can't swipe it?

 

Of course not. Nowadays, contactless bus cards (including but not limited to school meal cards, company attendance cards, community access cards, etc.) all use RFID technology. What is RFID technology? The basic working principle of RFID technology: When an RFID tag enters a specific magnetic field, it receives the RF signal emitted by the interpreter, and uses the energy obtained from the induced current to send product information stored in the chip, or actively sends a signal of a certain frequency; After the interpreter reads and decodes the information, it is sent to the central information system for relevant data processing.

 

Simply put, when the card in your hand is in the sensing area of the card reader, the card reader will emit an RF signal, causing your card to receive electricity through electromagnetic induction, charging the chip on the card, and then allowing the card reader to read the information on the card (usually the deduction or recharge of a bus card). Why do so many people think that bus cards cannot be read because they lack magnetism? Many people know that bank cards cannot be placed together with mobile phones and magnetic objects (due to the different principle of bank cards compared to RFID cards, bank cards read and write data on the card through a magnet on the back, and RFID cards store this time information in the card's chip). Perhaps people naturally believe that RFID cards cannot be placed together with mobile phones, The reason why RFID cards cannot be read is often because they are placed too close to metal objects such as metal phone shells. If the card is not damaged, it can be read by simply taking out the card separately.

 

The operation of NFC battery RFID cards is not directly related to the magnetism of the phone itself or its surroundings. The experiment showed that several RFID tags were placed in a 1.5T magnetic field for 5 minutes, 10 minutes, 30 minutes, and 1 hour respectively. It was found that the coil had a heating effect, but the RFID tag could still be read 100%. Therefore, placing RFID cards (tags) and mobile phones together will definitely not be affected by the opponent's machine.

 

The internal structure coils and chips of RFID cards are like the NFC function equipped on multiple flagship models. In fact, the NFC function is an improvement on RFID technology. The NFC chip is embedded inside the phone, which can obtain and exchange information through touch between the phone and other terminals.

 

The operation of NFC battery RFID cards is not directly related to the magnetism of the phone itself or its surroundings. The experiment showed that several RFID tags were placed in a 1.5T magnetic field for 5 minutes, 10 minutes, 30 minutes, and 1 hour respectively. It was found that the coil had a heating effect, but the RFID tag could still be read 100%. Therefore, placing RFID cards (tags) and mobile phones together will definitely not be affected by the opponent's machine.