SU1002968A1 - Flow speed measuring device - Google Patents

Description

The invention relates to a measuring technique and can be used to measure air square parameters.

Apparatus for measuring the airspeed of an aircraft, made in the form of total and static pressure difference meters and recorders of this difference by means of a membrane assembly, are known, with subsequent conversion of the movement of the rigid center of the membrane into a signal convenient for further use. comprising a housing with two chambers separated by a partition and connected respectively with full and static pressure lines, measuring el ment pressure differential, amplifier and recorder.

The internal volume of the body is divided into two chambers using a tetron knot. The hard center of the latter is shifted by the impact of the difference between the total and static pressures perceived by the irusculative pressure difference gauge 12.

The disadvantage of this device. there is a low measurement accuracy associated with the errors of the membrane assembly and the system for measuring the displacement of the rigid center of the membrane.

The purpose of the invention is to improve the measurement accuracy,

The goal is achieved by the fact that in the device containing

10 housing with two chambers separated by a partition and connected respectively with full and static pressure lines, differential pressure meter, amplifier and recorder, measuring element-pressure difference is made in the form of a rectangular conductive frame mounted on a string suspension and placed one from their parties to

20 gap of the magnetic system, as well as the frame position sensor, the output of which through the amplifier is electrically connected to the frame and the recorder. In this case, the partition between the cameras

25 is rigid: a wall provided with a capillary orifice located opposite the gap of the magnetic system.

FIG. 1 preftav.epl: peck-G - 30 kinematic cap-y-hp (:; nsg; .a,

for measuring flow rate parameters; in fig. 2 - a variant of the design of the proposed device; and in fig. 3 view L in FIG. 2

The device contains a quartz rectangular frame, made in the form of two racks 1 and strips 2, located on opposite sides of the axis of the string suspension 3. The frame is balanced relative to the axis of the strings 3. The frame and string elements are metallized, which allows one of the slats 2 placed in The gap of the magnetic system, made in the form of a permanent magnet 4, should be included in the circuit of the formation of the moments of feedback forces that balance the moment of external forces acting on the frame. This circuit includes a frame position sensor according to the measuring OC, made, for example, in the form of an optoelectronic pair 5 with an open optical channel. Plank 2 performs the functions of a damper and when it is biased by external power factors, an electrical signal from an optoelectronic pair 5 is fed to the input of a differential amplifier b, loaded onto successively connected electrical resistance of the frame elements and strings of the torsion suspension and load resistor 7. From the output of the latter form the output signal supplied to the registrator (not shown).

The capillary opening 8 has the form of a slotted capillary channel, through which separate chambers are connected, separated by a rigid partition 9. On sections of the capillary, the pressure of the gaseous medium is respectively equal to the full RPOL static. (The velocity vector of inflowing air is shown in Fig. 1 by arrows). The ends of the strings 3 and the displacement transducer are mounted on a quartz base 10, which is fixed in the lid 11. The lid 11 is provided with a germ. The inlet 12 and the inlet associated with the line, e.g. static pressure.

The second cap 13 has a receiving opening for communication with the full pressure main. The housing 14 with lids 11 and 13 form two chambers, respectively, of total and static pressures, connected between a capillary opening 8 in the rigid wall of the housing 14.

The device works as follows.

The gas stream flowing through channel 8 acts on the bar 2 frames, which are preliminarily balanced relative to the axis of string torsions. On the displacement sensor 5, an electrical signal arises, amplified by the amplifier 6 and supplied to the frame, which is an element

an electromechanical converter of power factors acting on one of the slats 2. The frame returns to its original position under the influence of this signal. The current flowing through the frame causes a voltage drop across the resistor 7, which is fed to the recorder.

The voltage drop Ug, on the load resistor 7, is functionally 5 related to the measured air velocity.

The carried out theoretical and experimental studies show that the proposed device 0 has advantages over the known membrane ones in terms of accuracy, mass, ha, barite, and has a lower time constant. Taking into account that the membrane unit is one of the most unstable elements in the composition of the proposed device and the compensation method of measurement is used, the accuracy of the measurement error can be reduced by a factor of 10.

Claims (2)

1.Bodner V.A. Aircraft instruments, M., Mashinostroenie, 1969, p. 323-324. 2. Seleznev V.L. Navigation devices, Oborongiz, 1E61, p. 209, (prototype).