ANTENNA DEVICE FOR METER INCORPORATING RADIO TRANSMISSION

摘要

PROBLEM TO BE SOLVED: To reduce the number of parts by connecting a radio communication part to a part of a piping pipe and providing an antenna by means of resonating a part of the piping pipe with a desired frequency. SOLUTION: A gas meter 1 measures gas use quantity and holds measured value information into a memory in the gas meter. A radio communication part 2 is provided in the gas meter for permitting a gas supplier to meter measured value information at a remote place. The radio communication part 2 converts measured value information in the memory in the meter into a high frequency signal. A power feeding part 3 feeds power to the piping pipe antenna part 5 of the piping pipe 4 and radiates a radio wave in space. The piping pipe 4 is formed by resin except for the part of a piping pipe antenna part 5 and high frequency current does not flow. The piping pipe antenna part 5 connected to the gas meter 1 is formed to aboutλ/4 of the wavelength of the desired frequency and it is resonated as aλ/4 monopole antenna by the physical length of the longitudinal direction of the piping pipe antenna part 5.