CN103234603B - Floater mechanism and measurement method used for measuring liquid level of liquid pressure meter - Google Patents

Abstract

The invention relates to a liquid pressure meter and belongs to the field of detection. A floater mechanism used for measuring the liquid level of the liquid pressure meter is arranged on a conductive medium liquid level of the liquid pressure meter, and is characterized by comprising a floater and a floater stabilization mechanism, wherein the floater comprises a floater body and a T-shaped measurement head; the floater body adopts an aluminum alloy floater body; the T-shaped top end surface of the measurement head is a polytetrafluoro diffuse reflection plane; extended stabilization grooves are formed in the two ends of the floater body respectively; the stabilization grooves are sleeved in vertical columns of left and right stabilization brackets fixed in a container of the liquid pressure meter; the two stabilization brackets are vertically arranged between the upper and lower planes in the container; the floater body is symmetrically arranged by a central line; the measurement head is arranged on the symmetry axis of the central line; and the inner wall of the container adopts a Teflon coating. According to the liquid pressure meter, the floater mechanism is applied to the liquid level of the liquid pressure meter, so that the height value of the liquid level can be very accurately obtained in combination with a measurement device, and the accuracy and the stability are very good.

Description

A kind of float mechanism for the measurement of liquid manometer liquid level position and measuring method

Technical field

The present invention relates to liquid manometer, particularly relate to a kind of float mechanism measured for liquid manometer liquid level position.

Background technology

Liquid manometer is that one utilizes liquid-column height difference directly to carry out tonometric instrument.Its maximum advantage is directly perceived, can by less pressure remained steady state, but will to realize the maximum technological difficulties that pin-point accuracy measures be that liquid level position is measured.Traditional measurement liquid level method is roughly divided into two kinds, a kind of is the position engraving liquid level in scale range estimation glass tube on glass tube, another kind method is adjustment liquid level and observes the inverted image that fixing cone is in a reservoir sharp and it is in liquid level, make it to be about to collide, the position of now boring point is exactly liquid level position.As shown in Figure 1, the most typical is exactly U-tube manometer, and accuracy of measurement is quite low.Method shown in accompanying drawing 2 is relatively accurate, and exemplary is exactly compensate-type micropressure meter, and liquid level position when its shortcoming first is balance is fixed, and it two is must come adjustment position with range estimation, is difficult to automatically control and digital communication.Except above two kinds of methods, current somebody adopts ultrasound wave directly to carry out liquid level position measurement.Hyperacoustic feature is that frequency is high, and wavelength is short, and diffraction phenomenon is little, and good directionality, can become ray and direction propagation.Liquid level is the long-pending of ultrasonic propagation velocity and delivery time, Distance=VT.Measuring principle is that when opening ultrasound wave, trigger pulse count down to stopping counting when receiving return signal, sees shown in accompanying drawing 3.In order to make measurement more accurate, some constants of ultrasound wave transmission can be demarcated with horizontal fixed range.Accuracy of measurement likely reaches the order of magnitude of a few percent millimeter.But, if adopt medium to be the liquid manometer of water, corresponding a few tenths of Pa pressure.Stability and the accuracy of measurement are then unsatisfactory.

Summary of the invention

Technical matters to be solved by this invention is to provide a kind of float mechanism measured for liquid manometer liquid level position, and solve present liquid manometer liquid level position and measure the range estimation of employing human eye or other method, degree of accuracy cannot ensure, the defect that consistance is very poor.

Technical scheme

A kind of float mechanism measured for liquid manometer liquid level position, be arranged on the conductive medium liquid level of liquid manometer, it is characterized in that: comprise float and float stabilizing mechanism, described float comprises buoyancy aid and "T"-shaped measuring head, buoyancy aid adopts aluminium alloy buoyancy aid, the "T"-shaped top end face of measuring head is polytetrafluoro diffuse reflection plane, buoyancy aid two ends have the gutter stretched out respectively, described gutter is enclosed within the vertical column of two center rests in left and right be fixed in the container of liquid manometer, described two center rests to be vertically arranged in described container between lower planes, described buoyancy aid is symmetrical arranged with center line, "T"-shaped measuring head is arranged on this center line axis of symmetry, described container inner wall adopts Teflon coating.

Further, the two ends, left and right of described buoyancy aid press close to be arranged on two, the left and right center rest in container respectively.

Further, described buoyancy aid is downward cone.

Further, described container is airtight container.

Further, be provided with laser displacement gauge on the container, coordinate liquid level in described float mechanism measuring vessel.

Beneficial effect

Float mechanism of the present invention is used on the liquid level of liquid press machine, coordinate laser displacement gauge or other measurement mechanism just point-devicely can obtain the height value of liquid level, and observe the change of liquid level, greatly improve compared with present eyes direct-view degree of accuracy, even if under minute-pressure change, also can accurately test, unaffected, stability is very good.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of a kind of measuring method of prior art.

Fig. 2 is the schematic diagram of the another kind of measuring method of prior art.

Fig. 3 is ultrasonic measurement principle schematic in prior art.

Fig. 4 is structural representation of the present invention.

Fig. 5 is the principle schematic that respective outer side edges laser displacement gauge of the present invention carries out liquid level gauging.

Wherein: 1-buoyancy aid, 2-measuring head, the "T"-shaped top end face of 3-measuring head, 4-gutter, 5-center rest, 6-pressure transmitting medium liquid level, 7-container, 8-semiconductor laser, the eyeglass before 9-laser instrument, 10-collects eyeglass, 11-CCD array, 12-signal processor, 13-testee.

Embodiment

Below in conjunction with specific embodiment, set forth the present invention further.

For solving the detection in minute-pressure situation, newly devise a kind of float mechanism, float mechanism is arranged on the conductive medium liquid level 6 in the container 7 of liquid manometer, whole float mechanism comprises float and float stabilizing mechanism, described float comprises buoyancy aid 1 and "T"-shaped measuring head 2, buoyancy aid 1 adopts aluminium alloy buoyancy aid, the "T"-shaped top end face 3 of measuring head is polytetrafluoro diffuse reflection plane, buoyancy aid 1 two ends have the gutter 4 stretched out respectively, described gutter 4 is enclosed within the vertical column of two center rests 4 in left and right be fixed in the container 7 of liquid manometer, described two center rests 4 to be vertically arranged in described container 7 between lower planes, center rest 4 can limit float and rotates and wave, see accompanying drawing 4.Laser displacement gauge above container 7, by the plane of reflection of laser beam directive diffuse reflection surface, carries out range observation according to the corresponding different reflection angle of different distances.Container 7 inwall of this float mechanism adopts Teflon coating, and to reduce the adhesion of inner surface of container to medium, make adhesion be less than cohesion between fluid molecule like this, liquid medium not easily produces wall cling phenomenon.

Merit attention, the development of this float mechanism must ensure the center of gravity of float and its center very consistent, not so float can tilt and on center rest 4, produce friction buoyant equilibrium is changed, therefore described buoyancy aid 1 is symmetrical arranged with center line, and "T"-shaped measuring head 2 is arranged on this center line axis of symmetry.

Described container 7 can be provided with laser displacement gauge, coordinate liquid level in described float mechanism measuring vessel.Laser displacement gauge adopts optic triangle method measuring principle (see accompanying drawing 5) to measure, and namely by the monochromatic light that semiconductor laser 8 penetrates, focuses on testee 13 by the eyeglass 9 before laser instrument.Reflected light is collected eyeglass 10 and collects, and projects on ccd array 11; Signal processor 12 obtains the distance apart from object by the trigonometric function light spot position calculated on ccd array 11.Illustrate in figure that testee 13 initial position is to the instrumentation plan of shift position.If plane of departure generation deflection, then must have influence on the accuracy of position measurement, so the floating state of float is very important.

In order to measure absolute pressure and vacuum, float mechanism must seal completely.Sealing mechanism divides three parts: one is the embedded toroidal rubber cushion sealing of upper cover, and second is the pressure vacuum sealing of pressure interface, and the 3rd is the logical light isolating seal of laser displacement gauge and mechanism.

During actual measurement, with without laser displacement gauge measured value D during pressure reduction ₀for zero-bit, laser displacement gauge reading D when measuring after pressurization _xa relative reading, actual liquid level position D:

D＝D _x-D ₀-----------（1）

Consider the temperature variation in measuring process, actual liquid level position also must carry out the temperature adjustmemt of Media density, if the Media density of original state is ρ ₀, the temperature funtion of Media density is ξ (t), then the Media density of duty is

${\mathrm{\ρ}}_t={\mathrm{\ρ}}_0+{\∫}_{t_0}^t\mathrm{\ξ}\left(t\right)\mathrm{dt}---\left(2\right)$

Equal according to Archimedes' principle buoyancy the weight arranging liquid, equal the gravity of float according to statics balance principle buoyancy, then can derive actual liquid level position

$D^{\′}=D_x-D_0+4\frac{(\frac{{\mathrm{\ρ}}_0}{{\mathrm{\ρ}}_t}-1)}{{\mathrm{\πd}}^2}{V}_0---\left(3\right)$

In formula: d is the external diameter of float; V ₀for float immerses the initial volume of medium.

Actual level change value can be calculated by formula (2) and (3).

According to the prior art level of laser displacement gauge, its position measurement uncertainty can reach 7 μ (k=2), and measurement range is 10mm.

This programme have developed the float mechanism in high-precision liquid pressure gauge in movable container and fixed container, and laser displacement gauge is arranged on above container 7, utilizes laser beam to carry out range observation to the plane of reflection of diffuse reflection surface.This float mechanism structure is simple, novel in design, realizes high-precision measurement.It had both expanded measurement range than original compensation pressure gauge and had turn improved uncertainty of measurement, and measurement data is directly digital form, can be used as the system that the pith automatically measured is introduced into full-automatic micro pressure measuring, make testing equipment practicality stronger, be more suitable for the requirement of actual micro-pressure measurement.

Claims (3)

1. the float mechanism measured for liquid manometer liquid level position, be arranged on the conductive medium liquid level of liquid manometer, it is characterized in that: comprise float and float stabilizing mechanism, described float comprises buoyancy aid and "T"-shaped measuring head, buoyancy aid adopts aluminium alloy buoyancy aid, the "T"-shaped top end face of measuring head is polytetrafluoro diffuse reflection plane, buoyancy aid two ends have the gutter stretched out respectively, described gutter is enclosed within the vertical column of two center rests in left and right be fixed in the container of liquid manometer, described two center rests to be vertically arranged in described container between lower planes, described buoyancy aid is symmetrical arranged with center line, "T"-shaped measuring head is arranged on this center line axis of symmetry, described container inner wall adopts Teflon coating, the two ends, left and right of described buoyancy aid press close to be arranged on two, the left and right center rest in container respectively, described buoyancy aid is downward cone, described container is airtight container.

2., as claimed in claim 1 for the float mechanism that liquid manometer liquid level position is measured, it is characterized in that: be provided with laser displacement gauge on the container, coordinate liquid level in described float mechanism measuring vessel.

3. apply the method that float mechanism as claimed in claim 1 carries out the measurement of liquid manometer liquid level position for one kind, it is characterized in that: in the liquid container of liquid manometer, be provided with described float mechanism, at described liquid container end face, be positioned at above float mechanism and be provided with laser displacement gauge, described laser displacement gauge adopts optic triangle method, with the polytetrafluoro diffuse reflection plane of described float mechanism for testee carries out displacement measurement, and calculate the height and position of liquid level in conjunction with the parameter of conductive medium and float mechanism.