SU3003A1 - Mercury vacuum gauge - Google Patents

Description

FIG. 1 is a front view of the vacuum gauge of FIG. 2 - longitudinally. vertical section and in fig. 3 is in horizontal section along the line AB in FIG. 2

The proposed device consists of a barometric tube 2, the lower open narrowed end communicating with a vessel filled with mercury. The latter is hermetically closed and in the upper part can communicate with the measured space through the 1-compartment 5, which enters the vessel from below. The upper part of the vessel / expands so that the air in the vessel, when the apparatus is tilted backwards, remains in space and could not get into the barometric tube 2. The height of the tube 5 above the mercury is maintained so that at its lowest a hundred n and mercury in a glass tube 2, i.e. when there is an absolute void on the right side of mercury, the top of tube 5 would be 3 mm above mercury. The amount of mercury in vessel 1 should be such that when the space D is connected to the atmosphere with

tube 5 or holes 11, the level of mercury should be equal to hole 7. Tube 5 is tightly fixed in vessel 7 by means of a nut 4 and has a thread at the outer end for connecting it to the measured space with a gas tube or a rubber tube tip. Tube hole 5 Closed b. The plugs 9 and 0 are used for the convenience of preparing and filling the device with mercury. Instrument readings are read on a scale of 3, graded in LT / SL1 and %% of the total vacuum in millimeters of mercury, and the readings take into account a decrease in mercury levels in the wide bend.

The apparatus is filled in the following way: in the cup 1 attached in the tilted position, the glass tube 2 filled with mercury is inserted from the bottom and is clamped with a rubber seal. Then the vessel is filled with mercury and the nrobka 9 is screwed in and the tube 5 without a plug b. A part of the mercury is poured out through the tube 5. Then the stopper is wrapped. B. In this position, the device can be shipped without fear of air entering the glass tube. When the device is installed, it is attached to the designated place in the right position. Then plugs 6 and 7 are opened, and the excess mercury is poured out, after which

bung

the instrument is wrapped

the stopper 5 is connected to the measurement space. Cork b serves only for the time of shipment of the device. A tap must be placed between the instrument and the measured space.

When working on a condenser at mercury vacuum gauges, water accumulation over mercury is often noticed. Sometimes water fills the entire glass tube and passes B; metal. In this case, the readings of the vacuum gauge are completely distorted - Due to the fact that in the proposed device the tube 5, going to the condenser, rises above the mercury by less than 10 mm, so the error from water accumulation will be less than 0.001 KrjcM. In addition, the appearance of such water

can be judged by closing the tap to the condenser and opening the plugs / 7 and 7; then all available water will flow out.

SUBJECT OF THE PATENT.

A mercury vacuum gauge consisting of a barometric tube connected to a closed wide vessel, the upper part of which is in communication with the measured space, characterized by the fact that the closed wide vessel 7 is provided with: a) a protrusion 8, thus positioned so that the space D over mercury, the air could not fall into the barometric tube when the device overturned backwards; b) tube 5 protruding slightly above the level of mercury in vessel 1 and serving to connect space D to the space being measured, and c) opening 7 being closed with a stopper and serving to mold mercury and being able to form above it.

Tvio-lithographs “K: Asny Pechatnik, Leningrad, International, 75