Patent ID: 7919326

Claim:
A method of tracking a status of a catalyst-driven process in a mixture, the method comprising: interrogating, with a Radio Frequency (RF) interrogation signal, a first set of Radio Frequency Identification (RFID) tags that is in a mixture, wherein each RFID tag in the first set of RFID tags is coated with a first coating that causes the RF interrogation signal to receive a first response from an interrogation of the first set of RFID tags, and wherein a corrosive in the mixture corrodes the first coating away at a rate such that the first coating is removed from at least one RFID tag, from the first set of RFID tags, at a same time that a catalyst in the mixture becomes activated; and determining that the catalyst in the mixture is actively processing the mixture when a different response is received from the interrogation of the first set of RFID tags, wherein the different response indicates that the first coating has been removed from a first pre-determined quantity of RFID tags from the first set of RFID tags.