主权项 |
1. A method for monitoring the condition of an article comprising the steps of:
a. affixing a covering made of a substrate that is coated with a layer of an electrically conductive material and forming a single electrically conductive surface that extends over the entire covering and has an electrical resistance, said covering being configured to at least partially encapsulate the article such that the article cannot be tampered with, without modifying the electrical resistance of said covering; b. producing an analog voltage value (VG) with a sensing device that is affixed to the electrically conductive surface of said covering; c. converting the analog voltage value (VG) into a digital voltage value (VG) with a data acquisition system; d. calculating a measured resistance RX from the digital voltage value (VG), the power supply (Vin) and known resistances (R1), (R2) and (R3) according to the equation RX=(R2*R3+R3*(R1+R2)VG/Vin)/(R1−(R1+R2)*VG/Vin) with a monitoring system; e. comparing the measured resistance (RX) to a known, nominal resistance (Rnominal) with the monitoring system; and f. generating an alert with a signaling means if the measured resistance (RX) is greater than the known, nominal resistance (Rnominal). |