| 摘要 |
PURPOSE: To report a fault by means of alarm and also to execute the remotereading of counted information of flow quantity by irradiating light to the optical reflection element of a flow meter rotor with an optical fiber, taking-out reflection light by means of the second optical fiber and converting it into an electric signal. CONSTITUTION: A reflection element 11 is provided on the stepping surface 12 of the rotary wheel 10 of the flow meter 1. The concentric optical fibers 21 and 22 are arranged between the flow meter 1 and an electronic meter block 100. The outside optical fiber 21 transmits light from a light emitting circuit 130 to the element 11. The inside optical fiber 22 introduces reflection light from the element 11 to a light reception converting circuit 140 which executes conversion into the electric signal. The output signal of the circuit 140 is compared with first and second threshold values S1 and S2 by a comparing circuit inside a block 100 and alarm is issued as the accident of optical fiber disconnection, etc., when the output is smaller than the threshold value S1. When the output is larger than the threshold value S2, a pulse is outputted, counted as the normal signal so as to be recorded in a memory 190 and automatically read from a remote place. |
