| 摘要 |
PROBLEM TO BE SOLVED: To simply and appropriately measure a flow rate of various kinds of liquid being fed.SOLUTION: The flow rate measuring device injects a gas v into a liquid w which flows in a flow passage 13 provided on a measured substrate 10 from a gas injection part 14, and provides a first light-emitting element 21a for emitting light on the flow passage as first detection means 21 at a position on the downstream side in the liquid feeding direction of the liquid of the gas injection part and a first light receiving element 21b for receiving light which is emitted from the first light emitting element and reflected in a portion of the gas, and provides second light emitting element 22a for emitting light on the flow passage as second detection means 22 at the position on the downstream side in the liquid feeding direction of the liquid of the first detection means and second light receiving element 22b for receiving light which is emitted from the second light emitting element and reflected in the portion of the gas, and measures a flow rate of the liquid flowing through the flow passage on the basis of the time until detected by the second detection means after the gas injected into the flow passage is detected by the first detection means. |
