| 摘要 |
PURPOSE:To provide a flow meter which can attain an automatic meter reading system of high reliability. CONSTITUTION:A flow meter is provided with a storage means 3 which elecrtronically stores the measurement data on a flow meter 2, a receiver means 7 which receives a request signal for transmitting the measurement data from the means 3 or an answer signal to the measurement data, and a receiving level detector means 44 which outputs one of those output signals set previously to the receiving level detected by a receiving level detector means 43 to a receiving level control means 33. The means 7 consists of an oscillator 32 which oscillates by the frequency approximate to the carrier signal frequency to be received, a phase difference detector 41, and a frequency corrector 42 which detects the difference between the carrier signal frequency and the signal frequency received from the means 32 and controls the oscillation frequency of the means 32 in order to reduce the preceding difference of frequencies. |
