GB1031050A - Apparatus for transferring a measured quantity of sample from one position to another - Google Patents

Abstract

1,031,050. Delivering measured quantities of liquid; sampling liquids. WARNER-LAMBERT PHARMACEUTICAL CO. July 2, 1963 [July 2, 1962], No. 26127/63. Heading B8N. An apparatus for transferring a measured quantity of sample from one position to another comprises a pump 16 for drawing in sample liquid from a container 13 and delivering a measured quantity thereof to a delivery point 22 and excess liquid to a drain 17, the flow of sample liquid between the container, delivery point and drain-being controlled by a valve 18. The pump comprises a plunger 24 movable in a barrel 23 which is connected via the valve 18 and a pipe 26 to a probe 14 adapted to be moved into the container 13, a pipe 27 connecting the valve with the drain 17. In operation, with the valve in the position shown in Fig. 1, the probe is inserted into the container and the plunger operated to draw in liquid into the probe, pipe and barrel, the initial flow of liquid cleaning the probe of any impurities left from the previous sampling operation. The probe is then raised to bring its end over the delivery point 22, and the plunger depressed, either manually or mechanically, a predetermined distance so as to deliver a measured quantity of liquid. Upon rotation of the valve, the remaining liquid is delivered to the drain. In the modification shown in Fig. 2, a probe 29 is connected by a pipe to a measuring chamber 39 of a plunger pump 31, the plunger 42 being connected to piston 41 whose stroke is varied by means of an adjusting screw 48; the piston is actuated either by air pressure or suction via a pump 52. The pump is also provided with a second measuring chamber 38 which is connected via a pipe 56, slide valve 32 and pipe 58 with a drain 59. In operation with the slide valve in the reverse position to that shown, so as to connect the suction side of the pump 52, via pipes 34, 54 to the piston chamber 37, the piston is raised, thereby causing the plunger 42 to draw in sample liquid from the container 13 into the measuring chamber 38, 39. Since the liquid must flow through the measuring chamber 39 before entering the chamber 38, the chamber 39 is cleansed of impurities. Upon reversal of the valve to connect the pressure side of the pump to the piston chamber 37, movement of the plunger 42 forces liquid in the chamber 39 to a delivery point over which the probe has been moved. The excess liquid in the chamber 38 is forced, via pipes 56 and 58, to the drain 59. In a further modification, in order to be able to vary, independently, the quantity of actual sample liquid and the quantity of excess liquid required for cleansing purposes, two separate pumps are used, each having only one measuring chamber and stroke varying means.