Patent ID: 7277020

Claim:
Apparatus for indicating the state of a characteristic of a constituent in a container, the apparatus comprising: a monitoring unit mountable on the container for monitoring the state of the characteristic of the constituent, the monitoring unit comprising: a sensor for monitoring the state of the characteristic of the constituent, a first microprocessor for reading a signal from the sensor and determining the state of the characteristic from the signal from the sensor, and a primary transmitter operable under the control of the first microprocessor for transmitting a signal indicative of the state of the characteristic of the constituent, and a receiving unit locatable remotely of the monitoring unit for indicating the state of the characteristic of the constituent, the receiving unit comprising: a primary receiver for receiving the signal indicative of the state of the characteristic of the constituent transmitted by the monitoring unit, and a means for providing a perceptible indication of the state of the characteristic of the constituent in response to the received signal, wherein the monitoring unit comprises a teaching means for selectively operating the monitoring unit and the receiving unit in a teaching mode for teaching an address of the receiving unit to the receiving unit, and the teaching means is responsive to the monitoring unit and the receiving unit being brought into close proximity with each other for operating the monitoring unit and the receiving unit in the teaching mode.