INTERROGATOR, NON-CONTACT DATA CARRIER SYSTEM, METHOD FOR ACQUIRING DATA OF NON-CONTACT DATA CARRIER, AND PROGRAM FOR ACQUIRING DATA OF NON-CONTACT DATA CARRIER

PROBLEM TO BE SOLVED: To maintain low cost and compact system even when a physical quantity measuring function is provided to a non-contact data carrier, and moreover, to increase flexibility of measurable physical quantity. SOLUTION: This non-contact data carrier system has an interrogator, a non-contact data carrier having a measurement port which transfers data with the interrogator, and a compared signal source which is connected to the measurement port and generates a signal to be compared according to the surrounding physical quantity. The non-contact data carrier has a measurement port to be connected, a comparison means for comparing the input signal to be compared with a threshold value and outputting the comparison result, a variable threshold value means which variably outputs the threshold value, and a comparison control means for performing communication with the interrogator for measurement. The interrogator repeats comparison of the comparison means while changing the threshold value, fetches information on the threshold value whose logic in the comparison result is changed, and acquires information on the physical quantity concerning the signal to be compared. COPYRIGHT: (C)2008,JPO&INPIT