Close proximity communication device and methods

A method, comprising:

• transmitting, by a receiver, a first encoded data packet including a first close proximity command and a communication identifier to a transmitter within a transmission range for close proximity communication, wherein the first close proximity command is a sensor initiate command for a first sensor;
• transmitting, by the transmitter in response to the received sensor initiate command, transmitter identification information, comprising or based on a transmitter serial number of the first sensor, to the receiver;
• transmitting, by the receiver, a second encoded data packet including a second close proximity command to the transmitter;
• transmitting, by the transmitter, one or more signals of the first sensor related to a monitored glucose level of a user in response to the received second close proximity command, wherein the first sensor has one or more first calibration parameters determined in conjunction therewith;
• and
• detecting, by the receiver, a presence of a second sensor based on data transmitted by the transmitter, wherein the second sensor is a replacement of the first sensor and, in response, notifying the user and preventing application of the one or more first calibration parameters to one or more signals of the second sensor.