| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology for maintaining a longer service life of equipment such as a cutoff valve and the like and to achieving high detection accuracy for a gas meter having a small fluidic element and a large fluidic element disposed in sequence in a channel and provided with a bypass channel and a bypass cutoff valve for bypassing the small element. SOLUTION: A flow detecting regions for the small element and for the large element are set having a part of the region overlapping to each other. A small flow rate detecting state for detecting gas flow rate by the small element by operating the cutoff valve to cut off gas flow and a large flow rate detecting state for detecting gas flow rate by the large element without operation of the cutoff valve to allow gas flow are switched over based on a flow rate value to be measured. The gas meter comprises a switchover means for switching over to the large flow rate detecting state when the flow rate reaches a first switchover flow rate in the small flow rate detecting state and to the small flow rate detecting state when the flow rate reaches a second switchover flow rate which is smaller than the first switchover flow rate in the large flow rate detecting state.
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