An apparatus and method of use for enabling a NAM device are provided. The NAM device is configured to authenticate its use each time a measurement is requested. The operation of the NAM device is governed by a refillable media card that tracks a predetermined number of authorized uses. The NAM device confirms that remaining authorized uses are available on the refillable media card. In addition to tracking the number of authorized uses of the NAM device, the media card may also store the results of the measurements for tracking by a tracking server. When the number of authorized uses on the media card is depleted, the media card may be refilled by completing a refill transaction over a wired or wireless communication network. Alternatively, the media card may be refilled at a kiosk station or a new media card may be obtained for use with the NAM device.