TW201314184A - Proportion multiple switching object level measurement method and apparatus - Google Patents

Abstract

The invention relates to a proportion multiple switching object level measurement method and apparatus. A plurality of electrodes are set in material trough based on height. An electrode pair is composed between two adjacent electrodes. W presents the width between adjacent electrode pairs. A channel is formed between two electrodes of each electrode pair. The channel has a length L, a angle θ in proportion to plane; when object level of material to be tested rises and contacts each electrode pair, height of level can be calculated by H=N×L×sinθ+N×W+[(S/L)×sinθ] wherein H is height of material to be tested, N is amount of swamped electrode pair, S is soak length of partly swamped electrode pair; statement variation situation of each electrode pair are further determined for analyzing if material to be tested has multiple liquid phase layer.

Description

Proportional multi-switching liquid level measuring method and device

The invention relates to a liquid level measuring device, in particular to a proportional multi-switching liquid level measuring device for measuring the height of a material to be tested using a plurality of electrodes.

The current capacitive liquid level measuring device, as shown in FIG. 11 , includes a measuring electrode 91, a reference electrode 92, a detecting resistor 96 and a measuring unit 90. The measuring electrode 91 is disposed on the measuring electrode 91. A barrel 93 containing a material to be tested is placed in contact with the material to be tested. The reference electrode 92 is formed by the barrel 93 itself and is connected to a ground via a detecting resistor 96. The measuring electrode 91 is connected to the reference electrode. 92 is arranged in parallel and maintained at a fixed distance. The two electrodes can be equivalent to a capacitor 94 to be tested. When the measuring unit 90 sends an AC signal to the measuring electrode 91, the capacitor 94 and the detecting resistor 96 are to be tested. A loop is formed, and a voltage drop is generated on the detecting resistor 96. The voltage drop is proportional to the change of the capacitor 94 to be tested. Therefore, measuring the voltage value of the two ends of the detecting resistor 96 can be inversely obtained to obtain the capacitance between the two electrodes. At the time, the height of the material to be side in the tank 93 can be correspondingly determined by the change of the capacitor 94 to be tested.

When the two electrodes are arranged in parallel and the equivalent capacitance value is measured, to obtain the corresponding height, there is a use limit thereof, when used in a liquid material to be tested with different dielectric coefficients or a solid material to be tested with air doping, Measuring the temperature, pressure, viscosity, conductivity, etc. of the material will cause an error in the aforementioned equivalent capacitance value. In addition, a stray capacitance 95 is formed between the barrel 93 and the ground point, so that the measuring unit 90 measures the detection. When the voltage of the resistor 96 is parallel to the two ends of the detecting resistor 96 due to the stray capacitance 95, an error is generated and the measuring unit 90 obtains an incorrect liquid level value of the object to be tested.

As mentioned above, the characteristics of different materials to be tested and the grounding method of the tank slot may cause an error in the equivalent capacitance value between the two electrodes, and the measuring device obtains an incorrect height measurement value; therefore, the main purpose of the present invention is A proportional multi-switching liquid level measuring method and apparatus for measuring the height of a material to be tested using a plurality of electrodes to solve the problem of generating a false height due to an equivalent capacitance value error.

The main technical means adopted for achieving the foregoing object is the method for measuring the above-mentioned proportional multi-switching liquid level, comprising: arranging a plurality of electrodes according to the height in a material tank, so that two adjacent electrodes respectively constitute an electrode For example, each electrode pair has a width W, and each of the pair of electrodes forms a channel between the two electrodes, the channel has a length L, an angle θ with respect to the horizontal plane; when the material to be tested is set in the material tank When the liquid level rises and contacts each electrode pair, the height of the liquid level is calculated according to the height calculation formula H=N×L×sinθ+N×W+[(S/L)×sinθ], where H is the test The height value of the material, N is the number of submerged electrode pairs, and S is the immersion length of the partially immersed electrode pair; the above-described proportional multi-switching liquid level measuring method further includes: an electrode pair for submerging the object to be tested a first signal state, the pair of electrodes that are not immersed has a second signal state; and all the electrode pairs are scanned in the following manner; one by one is determined whether the signal state of each pair of electrodes and the adjacent electrode pair is the same, and the electrode pair is defined by the same Switch times Adding 0 to the number, at the same time, defining the number of switching of the electrode pair plus 1; when the number of switching of the electrode pair is 1, it means that the measuring function is normal; when the number of switching of the electrode pair is greater than or equal to 2, indicating that the electrode pair is attached to the substance, It means that the measurement function is abnormal.

The first signal state of the pair of electrodes includes submerged and partially immersed; when all the electrode pairs are in the first signal state, the material tank is full of liquid level; if all the electrode pairs are in the second signal state, the material tank is It is the empty liquid level.

In order to achieve the foregoing object, the present invention further provides a proportional multi-switching liquid level measuring device, comprising: a measuring unit having more than one output/input 埠 for measuring the liquid level of the object to be tested; The electrode unit comprises a plurality of electrodes, each electrode is electrically connected to the measuring unit, and the two adjacent electrodes respectively form an electrode pair, and each electrode pair has a width W therebetween, and the electrodes of each electrode pair are respectively formed. a channel having a length L and an angle θ with respect to a horizontal plane; using a proportional multi-switching liquid level measuring device composed of the foregoing components, the measuring unit sequentially detects the state of each electrode pair, and can be divided into When the electrode pair is submerged, partially immersed and not immersed, when the liquid level of the material to be tested in the material tank rises and contacts each electrode pair, the formula H=N×L×sinθ+ can be calculated according to the aforementioned height. N×W+[(S/L)×sinθ], the measuring unit calculates the number of electrode pairs in three states separately, and obtains the height of the material to be tested, thereby making the material level measurement of the material to be tested more accurate.

For the first preferred embodiment of the present invention, please refer to FIG. 1 , which includes a measuring unit 10 and an electrode unit 20 connected to the measuring unit 10 , wherein the measuring unit 10 includes: a signal The generating unit 11 has an output terminal for outputting an AC signal; a sensing unit 12 includes more than one output/input port, wherein an output/input port is a signal input terminal and is connected to the signal generating unit. An output terminal of the multiplex switch unit 13 has a plurality of input ports and one or more output ports, each of which is connected to the electrode unit 20, and the output of which is connected to the output/input of the sensing unit 12; a signal processor 14 having more than one output/input port, wherein an output/input port is connected to the output/input port of the sensing unit 11, the signal processor 14 includes a signal amplifying unit 141, a filter 142, A signal rectifier 143 and an analog-to-digital converter 144; a microprocessor 15 having more than one output/input port, wherein an output/input system is connected to the output/input port connected to the signal processor 14; single Element 15, is electrically coupled to microprocessor 14.

The electrode unit 20 includes a plurality of electrodes, and the two adjacent electrodes are a first electrode 211 and a second electrode 212 respectively, and form an electrode pair 21, and a channel 210 is formed between the two electrodes 211 and 212 of the electrode pair 21, and the like. The electrode pair 22-24 is disposed in the same manner as the electrode pair 21, and the first electrode 211 and the second electrode 212 of the adjacent electrode of the electrode pair 21 respectively form a contact point, and the two contacts are respectively connected to the multiplexer. The respective inputs 切换 of the switching unit 13 are switched.

The multi-switching liquid level measuring device composed of the foregoing components generates an alternating current signal from the signal generating unit 11 and sends it to the sensing unit 12, and transmits the alternating current signal to the electrode unit 20 through the multiplex switching unit 13, and then The multiplexer switching unit 13 obtains the status signals of the electrode pairs 21 to 24 in the electrode unit 20, and sends the signal to the signal processor 14, which includes the signal amplifying unit 141, the filter 142, the signal rectifier 143, and the analog digital The converter 144 performs signal amplification, filtering, rectification, and analog/digital conversion, and then the microprocessor 15 determines the state of the electrode pair 21 based on the signal and calculates the height of the liquid level of the object to be tested.

With regard to the second preferred embodiment of the present invention, referring to FIG. 2, the electrode unit 20 is disposed in substantially the same manner as the first preferred embodiment, except that the channel 210 has a length L and an angle relative to a horizontal plane. θ, and a width W between each pair of electrodes 21 to 24, the height of the material to be tested is calculated as H = N × L × sin θ + N × W + [(S / L) × sin θ], wherein, H The height value of the material to be tested, N is the number of submerged electrode pairs, and S is the immersion length of the partially immersed electrode pair. In this embodiment, the height of the material to be tested is submerged by the electrode pairs 21 and 22 (N=2). And a partially immersed electrode pair 23, and the electrode pair 24 is not immersed, and the angle formed by each channel with the horizontal plane is 45°; then the height calculation formula can be written as H=2×L×sin45°+2×W+[ (S/L) × sin 45°], and substituting the length L of the electrode pair 21, the width W, and the size of the immersion length S of the partially immersed electrode pair, the height of the material to be tested can be obtained.

With regard to the third preferred embodiment of the present invention, referring to FIG. 3, the embodiment is substantially the same as the second preferred embodiment, except that the contacts of one of the electrode pairs are connected to the multiplex switch. One of the outputs/inputs of unit 13.

For the fourth preferred embodiment of the present invention, as shown in FIG. 4, the electrodes of the electrode unit 20 are staggered and arranged opposite each other. In this embodiment, the electrodes are composed of five electrodes 31-35, each of which is composed of five electrodes 31-35. The electrodes 31-35 have the same length and are respectively arranged at different heights and parallel phases, wherein the upper half of the electrode 31 is opposite to the lower half of the adjacent electrode 32, and is regarded as an electrode pair, and the second highest electrode. The upper half of 32 is again opposite the lower half of the adjacent electrode 33 to form another electrode pair, whereby adjacent electrodes (31, 32) (32, 33) (33, 34) (34, 35) An electrode pair will be constructed separately so that the microprocessor 15 can calculate the height based on the state between the electrodes.

Regarding the fifth preferred embodiment of the present invention, please refer to FIG. 5, which is substantially the same as the fourth preferred embodiment, except that the electrodes respectively form an angle θ with the horizontal plane.

With regard to the sixth preferred embodiment of the present invention, referring to FIG. 6, the embodiment adopts the electrode arrangement mode of the foregoing fourth embodiment, but is not limited to the fourth embodiment; the electrode unit 20 is mainly disposed in one On the flexible circuit board 40, a plurality of electrodes are formed thereon, and a plurality of electrode pairs are formed, and the flexible circuit board 40 is wound around a probe 41, and the respective electrode pairs on the flexible circuit board 40 are electrically connected to each other at most. The measuring unit 13 measures the liquid level of the object to be tested through the electrode unit 20 on the flexible circuit board 40, and further covers a non-conductive outer cover 42 on the outside of the probe 41 to measure different The liquid level of the conductivity material.

Furthermore, the present invention can further determine whether the electrode unit measurement function of the second to fifth embodiments is abnormal, or further determine whether the material to be tested has a multiple liquid phase layer; as shown in FIG. 2, it discloses that there are two electrode pairs 21 22 is submerged by the material to be tested, the electrode pair 23 is partially immersed, and the electrode pair 24 is not immersed; as shown in FIG. 7, the two electrodes of the submerged electrode pair 21, 22 change the electrode level corresponding to the liquid level. The capacitance value of the channel, the capacitance value is Where ε ₀ is a dielectric constant, ε is a relative dielectric constant, d is the width of the channel, and A is the area of the pair of electrodes; when the channel of the electrode pair is submerged by different materials to be tested, the relative dielectric constant The difference in ε causes a change in the capacitance value; the measuring unit 10 can measure the capacitance value of each electrode pair, such as the capacitance value of the electrode pair 21 C ₂₁ , the capacitance value of the electrode pair 22 C ₂₂ , and the electrode pair 23 The capacitance value of C ₂₃ and the electrode pair 24 is C ₂₄ ; when the capacitance value C ₂₁ is equal to C _{22 is} greater than C _{23 and is} much larger than C ₂₄ , the liquid level of the liquid level of the sample to be tested is known to be at the electrode pair 23 . Position, and the electrode pair 22 is submerged by the object to be tested, the capacitance value C ₂₂ is C _max , and the electrode pair 24 is not submerged by the object to be tested, and the capacitance value C ₂₄ is C _min , and the slope is By the aforementioned formula It can be seen that when the relative dielectric constant of ε is different, the capacitance value of the electrode pair changes, that is, the magnitudes of C _max and C _min are changed, so two different slopes are generated; when the equivalent measuring unit 10 calculates, each electrode is calculated. The cumulative value of the capacitance is obtained as shown in FIG. 8; by the physical properties of the material to be tested and between the pairs of electrodes, a linear slope relationship with the height of the material to be tested is formed, when the physical properties of the substance to be tested are Before the change, the relationship of the linear slope SA can be recorded in the data reference unit 15 of the measuring unit 10; when the physical property of the substance to be tested changes, the linear slope is changed to SR, so that it is compared with the SA, and can be determined. The extent to which a substance changes.

The invention can further determine whether the material to be tested has multiple liquid phase layers, as shown in FIG. 9 , the material to be tested is highly submerged by the three electrode pairs 21 to 23 and the partially immersed electrode pairs 24 (the signals generated by the device are generally referred to as the first a signal state), and the electrode pair 25 is not immersed (the signal generated is referred to as the second signal state), and the measuring unit 10 sequentially determines the state of each electrode pair 21~25, which is adjacent to the pair of electrodes When the signal status is different, the number of signal switching times is +1. If the signal status of the adjacent electrode pair is the same, the number of signal switching times +0 is defined; wherein the two electrode pairs 21, 22 are submerged in a first liquid phase layer, the electrode pair 23 is partially immersed in the first liquid phase layer and a second liquid phase layer, the electrode pair 24 is partially immersed in the second liquid phase layer and the electrode pair 25 is not immersed, and the measuring unit 10 respectively measures the capacitance value of each electrode pair. Wherein, when C ₂₁ is equal to C _{22 is} greater than C _{23 and} C _{24 is} greater than C ₂₅ , the liquid level of the liquid level of the test object is determined to be at the position of the electrode pair 23 and the electrode pair 24 , and the number of signal switching times is respectively on the electrode pair. 23 and the electrode pair 24 each +1, indicating that the material to be tested has Liquid phase layer.

Regarding the seventh preferred embodiment of the present invention, as shown in FIG. 10, the array electrode pairs 21-24 are mainly disposed in an outer tube 60, and the outer tube 60 is composed of a plurality of combined tubes 61-64. And forming a spindle electrode, wherein each of the pair of electrodes 21 to 24 is disposed in each of the combined tubes 61-64. In the embodiment, the pair of electrodes 21 to 24 and the combined tube 61-64 are at a liquid level. The arrangement of the electrodes 241 and 64 of each combination of the electrode pairs and the combination of the electrode pairs is electrically connected to the multiplexer switching unit 13 respectively, and the measuring unit 10 detects the combination of the electrodes. The state and capacitance value between the electrode 241 and the spindle electrode in the block can obtain the height level of the object to be tested at the segment height.

It can be seen from the foregoing that measuring the height of the material to be tested by the plurality of electrodes can improve the measurement accuracy, and solve the problem that the prior art uses the two parallel measuring electrodes to generate an error height due to the error of the equivalent capacitance value.

10. . . Measuring unit

11. . . Signal generating unit

12. . . Sensing unit

13. . . Multiplex switching unit

14. . . Signal processing unit

141. . . Signal amplification unit

142. . . filter

143. . . Signal rectifier

144. . . Analog digital converter

15. . . microprocessor

16. . . Data reference unit

20. . . Electrode unit

21~25. . . Electrode pair

210. . . aisle

211. . . First electrode

212. . . Second electrode

31~35. . . electrode

40. . . Flexible circuit board

41. . . Probe

42. . . Outer cover

60. . . Outer tube

61~64. . . Combination tube

90. . . Measuring unit

91. . . Measuring electrode

92. . . Reference electrode

93. . . Bucket

94. . . Capacitance to be tested

95. . . Stray capacitance

96. . . Sense resistor

Figure 1 is a block diagram of a circuit in accordance with a first preferred embodiment of the present invention.

Figure 2 is a schematic view showing the structure of an electrode unit according to a second preferred embodiment of the present invention.

Figure 3 is a schematic view showing the structure of an electrode unit according to a third preferred embodiment of the present invention.

Fig. 4 is a structural schematic view showing an electrode unit of a fourth preferred embodiment of the present invention.

Fig. 5 is a structural schematic view showing an electrode unit of a fifth preferred embodiment of the present invention.

Figure 6 is a schematic view showing the state of implementation of a fourth preferred embodiment of the present invention.

Fig. 7 is a graph showing the heights of the capacitance and the object to be tested in the second to fifth preferred embodiments of the present invention.

Figure 8 is a graph showing the slope of physical properties of a substance to be tested in the second to fifth preferred embodiments of the present invention.

Figure 9 is a schematic view showing the structure of an electrode unit according to a sixth preferred embodiment of the present invention.

Figure 10 is a schematic view showing the structure of an electrode unit according to a seventh preferred embodiment of the present invention.

Figure 11 is a schematic diagram of an existing capacitive level measuring device.

10. . . Measuring unit

11. . . Signal generating unit

12. . . Sensing unit

13. . . Multiplex switching unit

14. . . Signal processing unit

141. . . Signal amplification unit

142. . . filter

143. . . Signal rectifier

144. . . Analog digital converter

15. . . microprocessor

16. . . Data reference unit

20. . . Electrode unit

21~24. . . Electrode pair

210. . . aisle

211. . . First electrode

212. . . Second electrode

Claims (16)

A proportional multi-switching liquid level measuring method comprises: dividing a plurality of electrodes according to a height in a material tank, so that two adjacent electrodes respectively form an electrode pair, and each electrode pair has a width W respectively; Forming a channel between the two electrodes of each electrode pair, the channel having a length L and an angle θ with respect to a horizontal plane; when the liquid level of the material to be tested in the material tank is raised and contacting each electrode pair, Calculate the height of the liquid level according to the height calculation formula H=N×L×sinθ+N×W+[(S/L)×sinθ], where H is the height value of the material to be tested, and N is the submerged electrode pair. The number and S are the immersion lengths of the partially immersed electrode pairs. The proportional multi-switching liquid level measuring method according to claim 1, further comprising: when the electrode pair is submerged, the signal is the first signal state, indicating the first state (empty); The electrode pair is not immersed, and the signal is in the second signal state, indicating the second state (full); when more than one electrode pair is in the first signal state, more than one electrode pair is in the second signal state; When the signal state of the electrode pair is different, the number of signal switching times is +1. If the signal state of the pair of adjacent electrodes is the same, the number of signal switching times +0 is defined; wherein, if the number of signal switching times is 1, the electrode unit is normally measured; When the signal state switching occurs, the electrode pair is called a trigger electrode pair; if the signal switching number is greater than or equal to 2, it indicates that the electrode unit is abnormally measured. The proportional multi-switching liquid level measuring method according to claim 1, further comprising: when the electrode pair is submerged, the signal is the first signal state, indicating the second state (full); The electrode pair is not immersed, and the signal is in the second signal state, indicating the first state (empty); when more than one electrode pair is in the first signal state, more than one electrode pair is in the second signal state; When the signal state of the adjacent electrode pair is different, the number of signal switching times is +1. If the signal state of the adjacent electrode pair is the same, the number of signal switching times is defined as +0; wherein, if the number of signal switching times is 1, the representative electrode unit is normally measured. When the signal state switching occurs, the electrode pair is called a trigger electrode pair; if the signal switching number is greater than or equal to 2, it indicates that the electrode unit is abnormally measured. For example, in the proportional multi-switching liquid level measuring method described in claim 2 or 3, when the number of signal switching times is greater than or equal to 2, the first signal switching electrode pair A, the second signal switching electrode For the electrode pair C of B and the last signal switching, the electrode pair A is used as the reference position of the substance to be tested, and the difference between the electrode pair B and the electrode pair C of the last signal switching when the second signal is switched is regarded as A false signal that interferes with the substance. For example, in the proportional multi-switching liquid level measurement method described in claim 2 or 3, when the number of signal switching times is 1, and the physical properties of the substance to be tested between the pair of electrodes vary with the height of the liquid level of the object. There are X different slopes, indicating that the substance to be tested has X or more than one liquid phase layer. For example, in the proportional multi-switching liquid level measurement method described in claim 2 or 3, when the number of signal switching times is 1, the electrode pair A of the first signal switching is referred to as a trigger electrode pair, corresponding to the waiting Measuring a first physical quantity state a of the substance, a slope SA of the physical property of the substance to be tested measured between the pair of trigger electrodes as a function of the height of the liquid level of the substance, and a reference slope SR of the physical properties of the substance to be tested as a function of the measurement direction By the variation of the slope SA and the reference slope SR, the change in the physical properties of the substance to be tested can be calculated as a basis for judging the change of the substance. For example, in the proportional multi-switching liquid level measurement method described in claim 2 or 3, the plurality of electrode pairs are set according to the height level of the object to be tested, and the liquid level of the sample to be tested can be obtained in different ranges. height. The proportional multi-switching liquid level measuring method according to any one of claims 1 to 3, wherein the channel width between the pair of electrodes and the adjacent pair of electrodes may vary with the direction in which the channels are arranged. The proportional multi-switching liquid level measuring method according to any one of claims 1 to 3, wherein the channel angle θ is between -90° ≦ θ ≦ 90°. A proportional multi-switching liquid level measuring device comprises: a measuring unit having more than one output/input enthalpy; an electrode unit comprising a plurality of electrodes, each electrode being electrically connected to the measuring unit, and The two adjacent electrodes respectively form an electrode pair, and each of the pair of electrodes forms a channel between the two electrodes, the channel has a length L, an angle θ with respect to the horizontal plane and a width W between the pair of electrodes; The state of each electrode pair is submerged and partially immersed by the material to be tested. The height of the material to be side can be calculated as H=N×L×sinθ+N×W+[(S/L)×sinθ], and the material to be tested can be calculated. The height, where H is the height value of the material to be tested, N is the number of pairs of submerged electrodes, and S is the immersion length of the partially immersed electrode pair. The proportional multi-switching liquid level measuring device according to claim 10, wherein one or more combined tubes are disposed outside the electrode unit, and the combined tube is a hollow tube body having a bottom portion for receiving the a plurality of electrode pairs, and a contact is formed on the outer sidewall of the outer tube, so that the combined tube forms a spindle electrode, and the extending direction of the electrode is parallel to the measuring direction, and the spindle electrode and the measured grounding electrical property The connection of each electrode pair of the electrode unit forms a channel side by side, and the arrangement direction of the channel forms an angle θ with the measurement direction. The proportional multi-switching liquid level measuring device according to claim 10, wherein the electrode unit is disposed on a flexible circuit board, and a plurality of electrodes and a plurality of contacts are formed on the circuit board, and the plurality of electrodes are Each of the electrodes is electrically connected to the plurality of contacts; and an outer cover tube is disposed on the outer side of the electrode unit, and is a non-conductive hollow tube having a bottom portion for receiving a flexible circuit board having the electrode unit therein. The proportional multi-switching liquid level measuring device according to any one of claims 10 to 12, wherein the channel width between the pair of electrodes and the adjacent pair of electrodes may vary with the direction in which the channels are arranged. The proportional multi-switching liquid level measuring device according to any one of claims 10 to 12, wherein the channel angle θ is between -90° ≦ θ ≦ 90°. The proportional multi-switching liquid level measuring device according to claim 11, wherein the spindle electrode is one indicating that the combined tube is electrically connected in common. The proportional multi-switching liquid level measuring device according to claim 11, wherein the spindle electrode is a number indicating that the combined tube has no common connection, and the total number of the electrode pairs is the total number of the spindle electrodes. The multiple, meaning that the spindle electrode of one of the regions can be electrically connected to the n counting electrodes at the same time.