| 摘要 |
A meter comprises a disc 12 which rotates at a velocity proportional to the rate of consumption of electricity, gas etc. One face of the disc 12 is reflective except for a surface 31 which is non-reflective. A sensor 13 having an infra-red emitting diode and an associated phototransistor is mounted relative to the disc 12 and a count is electronically stored of the number of times the disc interrupts the beam of infra-red radiation. This information can be transmitted by wireless to a receiver. A second non-reflective surface may be provided so that reverse rotation of the disc 12, indicating tampering, may be detected. When the meter casing is closed an electrical switch is closed, tampering with the casing opening the switch. The meter may transmit information to a van. Alternatively a plurality of meters may transmit information to a central unit mounted on a lamp-post, the central unit transmitting information to the van. In a further embodiment a meter may transmit information to a central unit via one or more intermediate meters. <IMAGE> |
