SU61750A1 - Liquid metering device - Google Patents

Description

The exact dosing of reservoirs of thermometers of capillary tubes, micropipettes, test tubes, etc. using mercury is known.

The proposed device differs from the known ones in that a liquid collecting tank is fixed at the end of a burette having two air-tight tampons, between which a drop of mercury is located. Suctioning air from the burette into the tank collects a certain dose of fluid.

Such an instrument design allows liquid to be measured with water or other non-harmful substances.

P1a of FIG. 1 shows a diagram of the device; in fig. 2 - tank with a burette.

The tank / enters its open end 2 in the vessel 3 with the liquid. The tank is fixed at the end of the burette 4, the upper part 5 of which is somewhat wider than the middle part and is closed by a rubber stopper 6. A rod 7 tightly passes through the stopper, having a tampon S at the end of the material which allows air to pass through but detains mercury (for example, leather, etc.). Kremaleroy 9 rearranges bars 7 and tampon 8 vertically. At the lower end of the burette 4, there is a fixed swab 10 of the same material. Between the tampons 8 VL 10 there is a drop of mercury. The vessel 3 with the liquid is suspended from the lever 12, which is turned by pressing the pedal to the tape 13, the envelope roller 14. The upper part 5 of the burette is connected by a tube 15 to a hemispherical vessel 16, a closed rubber membrane 17, which can be pressed by a metal hemisphere 18 connected with a screw 19 lever 20 moving between two guide posts 21.

The lever 20 lifts the hemisphere 18, the membrane 17 is compressed, and under it some vacuum develops; thanks to the tube 15, the vacuum is set above the swab 5. A drop of mercury rises to

No. 61750-2 -

the tampon 8 and fits tightly against it, creating the necessary vacuum over the tampon 10. If before this end 2 of the tank / was lowered into vessel 3, then some amount of liquid from vessel 3 will be sucked into the tank /. If you press the hemisphere 18 onto the membrane 17 again, the air pressure above the tampon 8 rises to the initial one, a drop of 11 mercury drops on the tampon 10, will force the air out of the space between the tampon W and a drop of mercury and cause the previously collected exactly measured amount of liquid to flow out of the reservoir /. Before this vessel 5 must be released. When measured from a tank, only the amount of liquid that is collected by a pulsating mercury column is poured out. The instrument is adjusted to the required volume by installing a mercury column along the lower meniscus and burette bar by moving the tampon 8. To eliminate the effect of wetting the glass with liquid on the metering accuracy, an arbitrary amount of liquid is collected in the tank / in advance, which is in the process of working all the prem.

Subject invention

A device for measuring doses of liquid using a membrane that creates a vacuum in a liquid measuring device, characterized by the use of an open-bottom container fixed to the end of a burette equipped with air-permeable tampons and a drop of mercury between them in order to set certain doses of liquid into the tank suctioning air from the burette.

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