| 摘要 |
<p>A valve assembly for providing plural dilutions of a single liquid sample and comprising a pair of outer stationary elements (24, 28) sandwiching a rotatable element (26) which carries precise volume segmenting passageways (52, 54, 96). One outer element carries loops (46, 48, 50) each for metering and storing a precise volume of diluent. A continuous body of sample is introduced into the valve assembly along a path through a pair (52, 54) of the segmenting passageways and a pair of measured portions (aliquots) are isolated from said path. The rotatable element (26) is operated to direct one aliquot along with the content of one loop (46) to an exterior location (12) for forming a first dilution. The other sample aliquot is retained. The first dilution is introduced into the valve assembly along a path through the third segmenting passageway (96) an an aliquot thereof is isolated. Both it and the retained sample aliquot then are directed from the valve assembly to respective testing locations (14, 16) along with the respective content of the remaining loops (48, 50). Channels (140, 95) are provided in the inner faces of the outer elements (24, 28) and communicatively coupled. Entry (130) and outlet (82) ports enable cleaning reagent to be introduced therein, the sandwiched element (26) being rotatable 360 degrees whereby to rinse the facing interior surfaces of the valve assembly.</p> |
