An alarm system for monitoring one or more items, comprising:
- a controller;
- one or more pairs of electroconductive wires, wherein each pair of electrically conductive wires comprises a respective, first electrically conductive wire and a respective, second electrically conductive wire, the first and second electrically conductive wires each comprising a respective, far end and a respective, near end, wherein the far ends of the first and second electrically conductive wires of each pair of electrically conductive wires are connected to each other via a respective resistor;
- and
- an alarm emitter, configured to emit an alarm;
- wherein
- the one or more pairs of electrically conductive wires are wrapped around one or more items, and the near ends of the first and second electrically conductive wires of each pair of electrically conductive wires of the one or more pairs of electrically conductive wires are operatively connected to the controller;
- and further wherein
- the controller is configured to execute the steps of:
- monitoring a respective resistance across said each pair of electrically conductive wires, and
- activating the alarm emitter to emit the alarm when said respective resistance is greater than a first predetermined value or less than a second predetermined value, wherein the first and second predetermined values are greater and less than the resistance of the respective resistor of said each pair of electrically conductive wires, respectively;
- wherein the controller comprises one or more secondary resistors respectively corresponding to the one or more pairs of electrically conductive wires, wherein the respective resistor of each pair of electrically conductive wires of the one or more electrically conductive wires is arranged in series with a respective secondary resistor of the one or more secondary resistors via a respective electrical point, and further wherein the step of monitoring the respective resistance comprises monitoring a voltage at said respective electrical point;
- wherein the one or more pair of electrically conductive wires comprise a first pair of electrically conductive wires and a second pair of electrically conductive wires, wherein the near ends of the first and second electrically conductive wires of the second pair of electrically conductive wires are disconnectably connected to the controller, and further wherein the alarm system is configured to adopt a working configuration in which a bypass resistor is mounted to the controller in lieu of the second pair of electrically conductive wires, with the bypass resistor arranged in series with the respective secondary resistor corresponding to the second pair of electrically conductive wires, the bypass resistor configured such that the respective resistance monitored in the monitoring step is neither greater than the first predetermined value nor less than the second predetermined value.