CN1059597A

CN1059597A - Level-sensing device

Info

Publication number: CN1059597A
Application number: CN 91108963
Authority: CN
Inventors: 陈汉达
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-09-20
Filing date: 1991-09-20
Publication date: 1992-03-18
Anticipated expiration: 2006-09-20
Also published as: CN1023835C

Abstract

This kind of level-sensing device, electrode independent and that disconnect mutually joins with all respectively by capacitive transducer by computing system.The present invention can overcome the variation of temperature of charge, humidity, density etc. and the influence that the material fluctuation and change causes in order to continuous coverage, and these influences are automatically adjusted, and this level-sensing device is not afraid of and is stained with stagnant material, and the measuring accuracy height is easy to use.

Description

Level-sensing device

The invention belongs to surveying instrument, especially for the continuous coverage of various materials in the feed bin (graininess, Powdered) controlling level.

Level gauging has various surveying instruments at present, wherein comparatively common is China Patent No. 88220707.5 disclosed a kind of level indicators, its principal feature is that it is dielectric measured capacitance with material, capacitance measurement circuit and indicator are arranged, metallic object in the measured capacitance usefulness feed bin is as two electrodes of electric capacity, when passing feed bin, metallic object isolates with insulator, set up short metallic object in the bottom of feed bin, it and two electrodes of feed bin limit wall as building-out capacitor, when short metallic object passes feed bin with the insulator idol from, building-out capacitor becomes negative feedback to be added on the capacitance measurement circuit through the building-out capacitor metering circuit, though this level indicator has solved temperature in the storehouse, humidity, the problem that density etc. can normally be used under the situation of change significantly, but also there is the instrument more complicated in it, adjusts pretty troublesomely, and its measuring accuracy is not high enough.

The objective of the invention is to propose a kind of simple, easy to use, the level indicator that precision is high.

Principal feature of the present invention is computing system electrodes independent and that disconnect mutually join with all respectively by capacitive transducer, and this electrode is special, solved the variety of issue in measuring very effectively.

Level-sensing device of the present invention can continuous coverage, can overcome the influence that material fluctuation and change etc. causes in temperature of charge, humidity, variable density and the storehouse, and these influences are adjusted automatically, and this level-sensing device is not afraid of and is stained with stagnant material, and the measuring accuracy height is easy to use.

Fig. 1 is the level-sensing device system chart

A is that capacitive transducer, 15 is that electrode fixed head, 16 is that last switch electrode, 17 is that the 4th electrode, 18 is that third electrode, 19 is that second electrode, 20 is a switch electrode under first electrode, 21 is among the figure.

Fig. 2 is construction of cable figure, 1 is wire rope among the figure, 2 be sheath, 3 for heart yearn, 4 for sheath, 5 for the worn-out net of screen, 6 for sheath, 7 for the worn-out net of screen, 8 for sheath, 9 for the worn-out conductor of screen, 10 for sheath, 11 for the worn-out conductor of screen, 12 for sheath, 13 for electrode, 14 for sheath.

Fig. 3 is the electrode breakpoint graph.Number in the figure is identical with Fig. 2.

Describe the present invention in detail below in conjunction with accompanying drawing.Know that by Fig. 1 computing system is made up of computing machine, printer and display, electrode independent and that disconnect mutually joins with all respectively by capacitive transducer A to draw 6 lines on computers respectively, this example is an example with 6 utmost point electrodes, and number of electrodes can be adjusted as required, can be many, can lack.Its simple principle is, the electric capacity of the electrode that each is isolated mutually enters computing machine by capacitive transducer A and handles, draw the material level in the feed bin, because the electrode between upper and lower switch electrode adopts branch segmentation forms such as length, making adopts computing machine that measurement result is revised easily, so level gauging is only relevant with the material height, and be subjected to the influence of specific inductive capacity, temperature, humidity, density of medium in the storehouse very little.Again owing on electrode, adopted the electric capacity isolation technology, make to influence each other minimumly between four five equilibrium segmented electrodes, and drawing of electrode signal be achieved.

Tell about the course of work of level-sensing device below.Material at first floods nethermost switch electrode, output switching signal, the existing material of expression.

Material floods to first segment electrode, and output signal is the computer installation scale operation.

Material floods to second segment electrode, and the first electrode double as is used for the proportional compensation electrode.

When material flooded to the 3rd segment electrode, first and second electrode was used as the proportional compensation electrode.

When material flooded to the 4th segment electrode, first, second and third electrode was used as the proportional compensation electrode.

Material floods supreme switch electrode, and promptly output switching signal represents to buy securities with all one's capital the limit.

When the 4th electrode does not flood, can be used as air electric capacity sampling electrode correction air and change electric capacity.

When last switch electrode sends when buying securities with all one's capital signal, can draw the slope and the density difference of each electrode, carry out the height of materials linearization automatically and proofread and correct.In material decline process, push away promptly as can be known with said process is counter.

Fig. 2 is an electrode structural chart, and wire rope 1 is as the supporting member of electrode integral body among the figure, and upper/lower terminal is fixed at the bottom of Cang Ding and the storehouse, and sheath 2 is enclosed within the outside of wire rope, damage heart yearn 3 when preventing wire rope with signal core line 3 relative motions.Around the sheath 26 heart yearns are arranged, outside every heart yearn, be surrounded by one deck insulation course 4, the worn-out line 5 of the active screen of a signal core line is arranged, between insulation course 4 and insulation course 6 in case produce direct capacitance between stop signal heart yearn and the ground.The worn-out line of active screen constitutes with emitter follower circuit, also can make the worn-out line of active screen by other circuit.Skin 6 has one deck to shield worn-out ground plane again, and above structure can guarantee that 6 signal core lines do not disturb mutually.The insulating sheath 8 that has a cable molding technology to use in the outside of the worn-out ground plane 7 of screen, skin at sheath 8 has the worn-out conductor 9 of a screen, as ground plane, the skin that shields worn-out conductor 9 has an insulation course 10, there is an active shielding layer 11 outside of this insulation course, and the effect of insulation course 10 is that active shielding layer 11 is kept apart with ground plane 9.Active shielding layer 11 is with penetrating grade follower and measuring utmost point connection.Its effect is the distributed capacitance between isolated electrode 13 and the ground plane 9.There is an insulation course 12 outside of active shielding layer 11, and electrode 13 is enclosed within the outside of insulation course 12, and electrode 13 mainly is the electric capacity that is used for measuring between this electrode and the bulkhead.Last layer insulating 14 is to be used for preventing material moisture, in order to avoid electrode produces electric leakage.

Fig. 3 is an electrode cut-off point synoptic diagram.Can know by Fig. 3 how cable inside connects.6 leads of heart yearn 3 are received respectively on 6 corresponding electrodes, and the signal that electrode 13 measures reaches corresponding capacitive transducer A by heart yearn 3, and the signal of capacitive transducer A enters computing system and calculates, and draws the height of material level.Shield worn-out net 5 and be connected to source shielding layer 11, main effect is to prevent to produce between electrode 13 and the ground very big distribution interference capacitors.Shield worn-out net 7 and connect the worn-out conductor 9 of screen, prevent to produce cross interference between the active shielding layer 11, more than discussed the structure of an electrode,, do not discussed one by one at this because the structure of each electrode all is identical to ground.

Claims

1, level-sensing device is characterized in that computing system joins by capacitive transducer electrode independent with all respectively and mutual disconnection.

2, it is characterized in that being provided with up and down switch electrode by the described level-sensing device of claim 1, is the electrode of length five equilibrium at the electrode between the switch electrode up and down.

3, by claim 1,2 described level-sensing devices it is characterized in that said electrode by wire rope 1 as central supported, in the outside of wire rope sheath 2 is arranged, some heart yearns 3 are arranged outside sheath 2, these some heart yearns do not disturb mutually, skin at heart yearn 3 has sheath 8 and the worn-out conductor 9 of screen to be used for ground connection, between worn-out conductor 9 of screen and active shielding layer 11 insulation course 10 is arranged, and there is an insulation course 12 active shielding layer 11 outsides, electrode 13 is enclosed within on 12, and a sheath 14 is arranged in the outside of electrode 13.

4, it is characterized in that by claim 1,2 described level-sensing devices active shielding layer is to be made of emitter follower circuit.

5, it is characterized in that by the described level-sensing device of claim 3 active shielding layer is to be made of emitter follower circuit.

6, it is characterized in that being with sheath 4 outside the heart yearn 3 by claim 1,2 described level-sensing devices, shield worn-out net 5, sheath 6 and the worn-out ground plane 7 of screen be not to disturb mutually between the assurance signal core line 3.

7, it is characterized in that being with sheath 4 outside the heart yearn 3 by the described level-sensing device of claim 3, shield worn-out net 5, sheath 6 and the worn-out ground plane 7 of screen be not to disturb mutually between the assurance signal core line 3.