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

Claim 0:
1. An apparatus, comprising:
memory; and
processor circuitry to execute computer readable instructions to at least:
measure with a first sensor, a first magnetic field in at least three dimensions, the first magnetic field including a device magnetic field caused by a wire attached to a device to supply electricity to the device, the first sensor proximately arranged to the wire;
measure with a second sensor, a second magnetic field associated with an environment at least a first distance from the wire, the first distance from the wire to ensure the second magnetic field measured by the second sensor essentially does not include the device magnetic field;
compare (a) the first magnetic field as measured by the first sensor arranged proximate to the wire and (b) the second magnetic field as measured by the second sensor arranged the first distance from the wire to determine an operational status of the device; and
collect audience measurement data based at least in part on the operational status of the device.