PURPOSE:To reduce a flow rate error, by providing the brake of a rotor which operates in relation to a valve closing signal for closing a control valve, in the vicinity of the rotor. CONSTITUTION:A detector 6 is provided on a part of a duct 1 of the outside in the radial direction of a rotor 3 of a turbine meter 2. A flow rate pulse signal from the detector 6 is sent to a counting circuit 10, is counted and is displayed on a display meter 11. When a counting value of the counting circuit 10 coincides with a preset value set to a presetting circuit 13, a comparing circuit 15 generates a valve closing signal in a line L2, and a valve driving part 16 closes a control valve 7. A brake 20 which operates in relation to such a valve closing signal is provided.
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