Nippon Electric Co., Ltd.

Aichi Tokei Denki Co., Ltd.

Kimmon Manufacturing Co., Ltd.

Jun Fukui

Takeshi Yano

Kazuhiko Shirai

Mamoru Ikeda

Yutaka Hasegawa

Noboru Yamazaki

Masaharu Sakanaka

Takesh Yano

A meter for a liquid, such as water, comprises a measuring circuit (55) for measuring those measuring periods in response to a detection pulse sequence resulting from rotation of a body (30) rotated by the liquid, each of which may be defined either by a period of one complete rotation of the body or a predetermined interval, such as six seconds. The circuit produces measurement signals representative of individual amounts of the liquid used with the individual amounts accompanied by detection errors resulting from a variable flow rate of the liquid. A totalizing circuit (61), which may comprise an ROM or consist of a microcomputer, totalizes the individual amounts with the detection errors reduced.

Liquid meter comprising a circuit for reducing a detection error

A water meter eliminates the usual conversion gear trains by using a permanent magnet which rotates in proportion to the volume of water to be measured. A magnetic field sensor, comprising a ferromagnetic magnetoresistor, produces a sensor signal which varies as a function of the rotation of the magnet. A wave shaper forms the sensor signal into a sequence of pulses which drive a totalizer for producing a signal indicative of the volume of the water used. The output of the totalizer is supplied to an indicator device which displays the total amount of water passing through the meter, in terms of a predetermined unit of measure. Preferably, the sensor comprises at least two magnetoresistors for producing two sensor signals with a phase difference therebetween. The wave shaper then produces two pulse sequences for identifying a normal and an inverse flow of water, respectively. These two sequences cause the totalizer to count up or down, respectively.

Water meter comprising a ferromagnetic magnetoresistor coupled to a

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Machida, Japan

Jun Fukui