| 摘要 |
Dilution of liquid samples is effected by drawing one sample at a time through an aspirating tube (12) dipped into the sample and through a volumetrically calibrated measuring passageway (17) in a movable valve body (16) of a metering valve (11), whereupon the valve body (16) is moved and the sample volume trapped in the measuring passageway (17) is expelled into a mixing vessel (23) together with a predetermined, many times larger volume of liquid diluent such that the diluent rinses the measuring passageway. Further rinsing of the valve body (16) is then effected with wash liquid. Wash liquid is also passed to a rinsing vessel (32) in which the end portion of the aspirating tube (12) previously dipped into the sample is inserted so that this end portion is rinsed exteriorly with the wash liquid. In a final step, wash liquid in the rinsing vessel (32) is drawn through the aspirating tube (12) to rinse it interiorly, whereupon air is drawn until the aspirating tube and the measuring passageway (17) are emptied of liquid. |
