To make every integration display remain without disappearing even if noise, lightning surge, etc., are applied to a water meter, by making an integration displaying part of a water meter body a mechanical indication mechanism and making both integration displaying parts of an oscillator and a receiver digit wheels.

In the oscillator 32, an indication mechanism 36 of a water meter 31 performs an integration operation, a digit wheel 38 rotates, mechanically working with it, integration display that corresponds to the mechanism 36 is performed, the rotations of the wheel 38 become voltage pulses and they are outputted to a transmission cord 33. The cord 33 transmits voltage pulse that is outputted from a pulse output circuit 45 of the oscillator 32 to a receiver 34. The receiver 34 is provided with a terminal 46 that is connected to the cord 33, a stepping motor 47 and a digit wheel 48 which is rotated by it. With this, even if a microcomputer 43 on the side of the water meter is destroyed or becomes non operation state, it continues to operate without stopping, therefore, display value that corresponds to integration value by the mechanism 36 can always be read by the wheel 38.