| 摘要 |
A valve assembly is provided which comprises basically a stationary base and a slidable body member, the unit being attached to an analyzing instrument. The base includes a passageway for conducting a liquid stream to be analyzed, such as water, into the valve assembly. The slidable member includes a plunger or piston slidably carried in a chamber and an orifice which communicates with the chamber. At one point during sliding contact of the body member with the stationary base, the orifice is aligned with the passageway. At a later point the orifice lines up with a discharge port in the base which communicates with the analyzing instrument. As the orifice lines up with the passage the plunger is actuated to withdraw a precise amount of liquid sample into the chamber through the orifice. When the orifice lines up with the discharge port the plunger is again actuated to "shoot" the sample downwardly through the orifice and into the analyzing instrument.
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