DE77108C - Device for measuring the mean flow velocity in watercourses - Google Patents

Description

IMPERIAL

PATENT OFFICE. ^

PATENT LETTERING

CLASS 42: Instruments

Patented in the German Empire on February 8, 1894.

A method has become known from patent no can be measured directly in watercourses.

The same thing consists in that one. Tubes with holes on one side for the stream counteracts, thereby producing the mean speed pressure and mifst it. To measure the latter, a pressure gauge (manometer) is used with one on the water connected to floating vessels, through which the hydrostatic pressure is eliminated. This method of measuring the mean velocity pressure becomes cumbersome because that one has to operate two taps, each of which is in three different positions' must be brought to let the hydraulic pressure act on the pressure gauge. If it is taken into account here that one tap is below the water level, so one finds the endeavor to find an apparatus which is simpler and understandable is easier to use, like that of Patent No. 43932.

Such an apparatus is shown in Fig. 1 in side, Fig. 2 in front view. R ¹ is the perforated tube, which is opposed to the current with the holes and causes the water inside the tube to rise above the outer water level by a certain height; the latter corresponds to the mean speed pressure.

The same is measured in the manometer M , into which the inner and outer water level is sucked up, so that the difference between them, expressed directly as speed, can be read off here.

The float identified in patent no. 43932 with the associated lines, as well as the two taps are completely omitted here. Instead, the following facility met: .

On the pipe R ¹ a short pipe section R ² can be moved ¹ , which is sealed at its lower end against R ^{1 by a stuffing box;} After setting the instrument into the stream, it is placed by means of the push rod S and its clamps K in such a way that the stuffing box comes 6 to 8 cm below the water level. The water rising inside R ¹ above the outer water level passes through the holes in R ¹ into the space between R ¹ and i? ² and in which with the latter .cummunicirende "tube R is ^s. This compared to another tube i? * Arranged, which dips with its lower slotted end below the water level, the water DAF in it at the height of the outward water level is.

The water level in R ³ and i? ⁴ (the hydrostatic and the hydrodynamic) are now sucked up by sucking the air out of the manometer through the two hoses E ¹ and E ^% into the latter and their difference is measured here.

The manometer consists of two nested glass tubes G ¹ and G ² , the inner G ¹ respectively through the hose E ¹ with R ^3. i? ² and R ^J are connected, while the outer G ³ (or the space between the inner

and outer) through the hose i? ^{2 is associated} with R ⁴ . In the inner glass tube there is also a narrow, light glass tube G ³ , which is closed at the top and bottom to form a float and contains the scale. The swimmer is so stressed that the zero point at the top of the scale coincides exactly with the water level.

If an air void is now created in the manometer, do the two water levels from R ^s and J rise? ⁴ in the manometer up; the swimmer goes with the inner (higher) water level and participates in its fluctuations; the outer (lower) water level shows the difference between the two on the scale. the mean speed.

The arrangement of the manometer with a vibrating scale has the essential advantage that only one water level, namely the outer one, needs to be observed, and consequently whose whole attention of the observer remains on the one point. The fluctuations can easily be followed and the reading can be effected quickly and reliably will.

Claims (1)

Patent Claims:
Device for direct measurement of the mean. Larger flow velocity in watercourses according to the Mefs method made known by patent no. 43932, characterized in that the hydrostatic water level as well as the hydrodynamic water level by appropriately separated lines (R ⁱ R ² R ^s E ^{} and} R * E ^) with a Manometer are connected, into which they are drawn by sucking the air, so that here their difference, expressed directly as speed, can be read off. An embodiment of the device identified under 1., in which the manometer consists of two mutually plugged, mutually closed glass tubes (G ¹ and G ^) , one of which receives the hydrodynamic water level and the other the hydrostatic water level, the difference between the two water levels is read on a scale arranged on a float of the hydrostatic water level, the zero point of which at the top coincides with the latter. 1 sheet of drawings.