Patent ID: 11940475
Assignee: THE NIELSEN COMPANY (US), LLC
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 7:
8. An apparatus, comprising:
memory; and
processor circuitry to execute computer readable instructions to at least:
measure, using a first sensor, a first magnetic field associated with a wire at a first distance from the wire, the wire to supply power to a device;
measure, using a second sensor, a second magnetic field at a second distance, greater than the first distance, from the wire, the second distance to reduce detectability of the first magnetic field;
compare (a) the first magnetic field measured at the first distance and (b) the second magnetic field measured at the second distance to determine an operational status of the device, the operational status based on a device magnetic field vector magnitude determined from the first and second magnetic fields, the device magnetic field vector compared to a power threshold vector magnitude of the wire; and
collect audience measurement data based at least in part on the operational status of the device.