GB961332A - Method and device for the automatic dosage of liquids - Google Patents

Abstract

961,332. Raising liquids. C K D DUKLA, NARODNI PODNIK. July 26, 1961 [July 27, 1960], No. 27154/61. Heading FIR. In a method and device utilizing pneumatic suction or pressure impulses for dispensing a liquid at a controlled rate, a pipette 1 is filled from a reservoir 6 either by gravity, or by the suction part of a pneumatic impulse acting via a pipe 8, Fig. 1, and is discharged through a liquid trap 2 either by the pressure part of the impulse or by gravity, respectively, the pipette being located either below or above the reservoir. The pneumatic suction and pressure impulses may be produced by a reciprocating diaphragm 9. Volume changes in the system, due to entrained gases or temperature changes, are corrected either by a liquid trap 11 or by a constricted opening to atmosphere. The diaphragms of two devices may be operated by a common eccentric. In the embodiment of Fig. 3, for dispensing two liquids, two devices discharge into a container 16, one via a siphon 14, the two liquids then passing through a tube 19 via a siphon 17. Pneumatic impulses produced by liquid passing an inclined tube in tube 19 serve to actuate the second device via a liquid trap 20. The level of the second liquid in a reservoir 22 is maintained constant relative to the second device by supporting reservoir 22 on a float 23 in a constant-level reservoir, the float and reservoirs being suitably dimensioned. A floating cover 28 may be provided. In an embodiment for producing impulses, Fig. 4, a tube 29 is connected to a pipette and to an intermittently or constantly filled siphon 30, the capacities of the siphon and tube 29 being varied by rings 31 and 32. Specifications 720,161 and 793,828 are referred to.