| 摘要 |
The introduction of a sequence of gas and liquid segment into a conduit (70), as for example in a continuous flow analysis machine, is metered by providing sensors (92a-92e) along the conduit and, downstream of the sensors, some valves (94a-94c, 96). Each valve is arranged to close the conduit to prevent further aspiration of fluid, in response to a signal from a sensor. The sensors sense a flow parameter of the segmented fluid stream, e.g. the leading edge of a segment, and are so positioned that the volume of a fluid aspirated is controlled. The valves are each positioned so that, upon actualion to close the conduit, they intersect a gas segment and not a liquid segment. |
