A resistance type magnetic float liquid level gauge measurement system and method

Abstract

The present invention provides a resistive magnetic float liquid level gauge measurement system and method, wherein the measurement system includes: a sensor module, the sensor module includes multiple resistors, multiple reed switches and a magnet; a measurement module, connected to the sensor module, used to measure the total resistance voltage when the reed switch is not turned on, and the total resistance voltage when the reed switch is turned on; a compensation module, the compensation module is used to compensate the total resistance voltage when the reed switch is turned on according to the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on, so as to obtain a compensated voltage; a circuit conversion module, the input end of the circuit conversion module is connected to the compensation module to receive the compensated voltage, the circuit conversion module is used to obtain a calibration detection value, realize the error compensation function, and eliminate the influence of the magnet position on the liquid level measurement accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid level gauges, and in particular to a resistance-type magnetic float liquid level gauge measurement system and method. Background Art

[0002] Among the two-wire instruments and meters in industrial automation, the resistive magnetic float level gauge is a widely used liquid level measuring instrument. The circuit of the resistive magnetic float level gauge includes a resistor, a reed switch, and a magnet. The reed switch is a normally open type. When the magnet changes with the liquid level, the reed switch orthogonal to the magnetic lines of force of the magnet is closed. The voltage between the common terminal of the reed switch and the zero-scale terminal changes linearly with the increase and decrease of the liquid level, realizing the liquid level measurement function. Generally, given the high sensitivity of the reed switch, when the magnet controls the closure of the reed switch at the actual measurement position, it will also cause one or more reed switches adjacent to the reed switch at the actual position to be closed. Therefore, the actual measurement obtained is the position error of one or more reed switches. Assuming that one reed switch indicates a liquid level of 5mm, two reed switches will have an error of 10mm. The resulting error will result in a low accuracy of the actual measurement result of the liquid level gauge. Summary of the invention

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a complete invention title for solving the problem of low accuracy of actual measurement results of the liquid level meter in the prior art.

[0004] To achieve the above-mentioned purpose and other related purposes, the present invention provides a resistive magnetic float level gauge measurement system, including: a sensor module, the sensor module including multiple resistors, multiple reed switches and a magnet; a measuring module, connected to the sensor module, for measuring the total resistance voltage when the reed switch is not turned on, and the total resistance voltage when the reed switch is turned on; a compensation module, the compensation module is used to compensate the total resistance voltage when the reed switch is turned on according to the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on, so as to obtain a compensated voltage; a circuit conversion module, the input end of the circuit conversion module is connected to the compensation module to receive the compensated voltage, and the circuit conversion module is used to obtain a calibration detection value.

[0005] Optionally, the compensation module includes an amplifier unit, a subtractor unit, a ratio setting unit and an adder unit; the input end of the amplifier unit is connected to the first output end of the measurement module, for receiving the total resistance voltage when the reed switch is turned on, so as to obtain a first voltage and a second voltage; the input end of the subtractor unit is connected to the output end of the amplifier unit and the second output end of the measurement module, for receiving the second voltage and the total resistance voltage when the reed switch is not turned on, so as to obtain a third voltage; the input end of the ratio setting unit is connected to the output end of the subtractor unit, for receiving the third voltage, so as to obtain a fourth voltage; the input end of the adder unit is connected to the output end of the amplifier unit and the output end of the ratio setting unit, for receiving the first voltage and the fourth voltage, so as to obtain the compensated voltage.

[0006] Optionally, the amplifier unit of the compensation module includes a first amplifier unit and a second amplifier unit, the input end of the first amplifier unit is connected to the first output end of the measurement module, for receiving the total resistance voltage when the reed switch is turned on, so as to obtain a first voltage; the input end of the second amplifier unit is connected to the first output end of the measurement module, for receiving the total resistance voltage when the reed switch is turned on, so as to obtain a second voltage; the input end of the subtractor unit is connected to the output end of the second amplifier unit and the second output end of the measurement module, for receiving the second voltage and the total resistance voltage when the reed switch is not turned on, so as to obtain a third voltage; the input end of the ratio setting unit is connected to the output end of the subtractor unit, for receiving the third voltage, so as to obtain a fourth voltage; the input end of the adder unit is connected to the output end of the first amplifier unit and the output end of the ratio setting unit, for receiving the first voltage and the fourth voltage, so as to obtain the compensated voltage.

[0007] Optionally, a display module connected to the output end of the circuit conversion module is also included to display the liquid level height value.

[0008] Optionally, the subtractor includes a subtraction circuit and a voltage setting circuit, the input end of the voltage setting circuit is connected to the second output end of the measurement module, and the output end of the voltage setting circuit is connected to the output end of the subtraction circuit.

[0009] Optionally, the proportion setting unit of the compensation module includes: a first resistor, a second resistor, a sliding rheostat, a first capacitor and an operational amplifier; the output end of the subtractor unit is connected to one end of the first resistor, and the other end of the first resistor is connected to the second resistor; the other end of the second resistor is connected to the sliding rheostat; the other end of the sliding rheostat is connected to one end of the first capacitor and grounded; the other end of the first capacitor is connected to the node of the first resistor and the second resistor and to the first input end of the operational amplifier; the second input end of the operational amplifier is connected to the output end of the operational amplifier; the sliding rheostat is used to set the compensation amount proportion parameter of the compensation module.

[0010] Optionally, in the resistive magnetic float level gauge measurement system, the fourth voltage satisfies the following formula:

[0011] V4=(Vt1-Vt2) / 2

[0012] Among them, V4 is the fourth voltage; Vt1 is the total resistance voltage when the reed switch is not turned on; Vt2 is the total resistance voltage when the reed switch is turned on.

[0013] Optionally, the compensation proportional parameter is 0.5. In some embodiments, the compensation proportional parameter can be adjusted according to the relationship between the magnetic steel position and the liquid level position. The ratio is adjustable between 0.25 and 0.75. When the reed switch is symmetrically conductive up and down at the magnetic steel position, the compensation proportional parameter is 0.5.

[0014] The present invention also provides a resistive magnetic float liquid level gauge measurement method, the resistive magnetic float liquid level gauge measurement system includes a sensor module, a measurement module connected to the sensor module, a compensation module connected to the measurement module, a circuit conversion module connected to the compensation module and the display module connected to the circuit conversion module, wherein the sensor module includes multiple resistors, multiple reed switches and magnetic steel, and the resistive magnetic float liquid level gauge measurement method includes: measuring the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on by the measurement module; inputting the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on into the compensation module to obtain a compensated voltage; inputting the compensated voltage into the circuit conversion module to obtain a calibration detection value; and displaying the calibration detection value through the display module.

[0015] In this way, by measuring the total resistance voltage when the reed switch is not turned on, and then subtracting it from the total resistance voltage when the reed switch is turned on, a difference, i.e., the third voltage, is obtained, and then a compensation voltage, i.e., the fourth voltage, is obtained by performing a proportional operation on the difference. Then, the compensation voltage is added to the measured voltage, i.e., the total resistance voltage when the reed switch is turned on, to obtain the compensated voltage, thereby realizing the error compensation function and eliminating the influence of the magnetic steel position on the liquid level measurement accuracy.

[0016] Optionally, the compensation module includes an amplification unit, a subtractor unit, a ratio setting unit and an adder unit, and the resistive magnetic float level gauge measurement method includes: inputting the total resistance voltage when the reed switch is not turned on into the amplification unit to obtain the first voltage and the second voltage; inputting the second voltage and the total resistance voltage when the reed switch is turned on into the subtractor unit to obtain the third voltage; inputting the third voltage into the ratio setting unit to obtain a fourth voltage; and inputting the first voltage and the fourth voltage into the adder unit to obtain the compensated voltage.

[0017] Optionally, the resistive magnetic float level gauge measurement method further includes setting a compensation amount ratio parameter through the compensation module.

[0018] As described above, the present invention provides a resistive magnetic float liquid level gauge measurement system and method, which combines a sensor module, a measurement module and a compensation module. The measurement module measures the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on; the control compensation module subtracts the total resistance voltage when the reed switch is not turned on from the total resistance voltage when the reed switch is turned on to obtain a difference, i.e., a third voltage, and then performs a proportional operation on the obtained difference to obtain a compensation voltage, i.e., a fourth voltage, and then adds the compensation voltage to the measurement voltage, i.e., the total resistance voltage when the reed switch is turned on, to obtain the compensated voltage, thereby realizing the error compensation function and eliminating the influence of the magnetic steel position on the liquid level measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Shown is a module schematic diagram of a resistive magnetic float level gauge measurement system of the present invention.

[0020] Figure 2 Shown is a schematic diagram of a sensor module of a resistive magnetic float level gauge measurement system of the present invention.

[0021] Figure 3 Shown is a module schematic diagram of another resistive magnetic float level gauge measurement system of the present invention.

[0022] Figure 4 Shown is a specific circuit schematic diagram of an amplifying unit in a compensation module of a resistive magnetic float level gauge measurement system of the present invention.

[0023] Figure 5 Shown is a specific circuit diagram of a subtractor unit in a compensation module of a resistive magnetic float level gauge measurement system of the present invention.

[0024] Figure 6 Shown is a specific circuit diagram of a ratio setting unit in a compensation module of a resistive magnetic float level gauge measurement system of the present invention.

[0025] Figure 7 Shown is a specific circuit diagram of an adder unit in a compensation module of a resistive magnetic float liquid level gauge measurement system of the present invention.

[0026] Figure 8 Shown is a flow chart of a resistive magnetic float level gauge measurement method of the present invention.

[0027] Component number description

[0028] 10 Sensor Module

[0029] 20 Measurement modules

[0030] 30 Compensation module

[0031] 31 Amplification unit

[0032] 311 First Amplification Unit

[0033] 313 Second Amplification Unit

[0034] 33 Subtractor unit

[0035] 331 Subtraction circuit

[0036] 333 Voltage Setting Circuit

[0037] 35 scale setting units

[0038] 37 Adder Unit

[0039] 40 Circuit Conversion Module

[0040] Steps S10 to S40 DETAILED DESCRIPTION

[0041] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0042] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0043] See also Figure 1 The present invention provides a resistance type magnetic float liquid level gauge measurement system, comprising:

[0044] A sensor module 10, wherein the sensor module 10 includes a plurality of resistors, a plurality of reed switches and a magnet;

[0045] The measuring module 20 is connected to the sensor module 10 and is used to measure the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on;

[0046] A compensation module 30, the compensation module 30 is used to compensate the total resistance voltage when the reed switch is turned on according to the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on, so as to obtain a compensated voltage;

[0047] A circuit conversion module 40 , wherein an input end of the circuit conversion module 40 is connected to the compensation module 30 to receive the compensated voltage, and the circuit conversion module 40 is used to obtain a calibration detection value.

[0048] In some embodiments, the compensation module 30 includes an amplifier unit 31, a subtractor unit 33, a ratio setting unit 35 and an adder unit 37; the input end of the amplifier unit 31 is connected to the first output end of the measurement module 20, and is used to receive the total resistance voltage when the reed switch is turned on to obtain a first voltage and a second voltage; the input end of the subtractor unit 33 is connected to the output end of the amplifier unit 31 and the second output end of the measurement module 20, and is used to receive the second voltage and the total resistance voltage when the reed switch is not turned on to obtain a third voltage; the input end of the ratio setting unit 35 is connected to the output end of the subtractor unit 33, and is used to receive the third voltage to obtain a fourth voltage; the input end of the adder unit 37 is connected to the output end of the amplifier unit 31 and the output end of the ratio setting unit 35, and is used to receive the first voltage and the fourth voltage to obtain the compensated voltage.

[0049] See also Figure 2 , Figure 2 It is a schematic diagram of a sensor module 10 of a resistive magnetic float level gauge measurement system. It can be understood that Figure 2T1 is the 100% range terminal, T2 is the common terminal of the reed switch, and T3 is the 0% range terminal. The resistor network is powered by a constant current source, which flows into T1 and out of T3. The sensor is composed of multiple resistors, multiple reed switches and magnetic steels. The multiple resistors are R1, R2, R3...RN; in some embodiments, R1=R2=...RN=10 ohms, the reed switches are S1, S2...SN, and the reed switches are normally open. When the magnetic steel changes with the liquid level, the reed switch orthogonal to the magnetic lines of force of the magnetic steel is closed, and the voltage between T2 and T3 changes linearly with the increase and decrease of the liquid level, thereby realizing the liquid level measurement function. The position of the magnet represents the actual position of the liquid level. When the magnet is at the third reed switch S3, due to the magnetic strength of the magnet and the sensitivity of the reed switch, the reed switch adjacent to the third reed switch S3 will also be turned on. For example, the two reed switches adjacent to the actual position are both turned on. At this time, the reed switches S1-S5 are all turned on. The instrument measures the voltage between T2 and T3, but actually measures the liquid level at the S5 position. This produces a position error of the two reed switches. Assuming that one reed switch represents a liquid level of 5 mm, the error of two reed switches is 10 mm. Therefore, through the combination of the sensor module 10, the measurement module 20 and the compensation module 30, the error compensation function is realized, eliminating the influence of the magnet position on the liquid level measurement accuracy.

[0050] See also Figure 3 In some embodiments, the amplifier unit 31 of the compensation module 30 includes a first amplifier unit 311 and a second amplifier unit 313, the input end of the first amplifier unit 311 is connected to the first output end of the measurement module 20, and is used to receive the total resistance voltage when the reed switch is turned on to obtain a first voltage; the input end of the second amplifier unit 313 is connected to the first output end of the measurement module 20, and is used to receive the total resistance voltage when the reed switch is turned on to obtain a second voltage; the input end of the subtractor unit 33 is connected to the output end of the second amplifier unit 313 and the second output end of the measurement module 20, and is used to receive the second voltage and the total resistance voltage when the reed switch is not turned on to obtain a third voltage; the input end of the ratio setting unit 35 is connected to the output end of the subtractor unit 33, and is used to receive the third voltage to obtain a fourth voltage; the input end of the adder unit 37 is connected to the output end of the first amplifier unit 311 and the output end of the ratio setting unit 35, and is used to receive the first voltage and the fourth voltage to obtain the compensated voltage.

[0051] In some embodiments, the resistive magnetic float level gauge measurement system of the present invention further includes a display module connected to the output end of the circuit conversion module 40 for displaying the liquid level value. The display module may be a liquid crystal display screen, so that the user can intuitively read the displayed height of the liquid level.

[0052] See also Figure 4 , Figure 4 is a specific circuit diagram of the amplifying unit 31 in the compensation module 30. The amplifying unit of the compensation module 30 includes a first amplifying unit 311 and a second amplifying unit 313. The input end of the first amplifying unit 311 is connected to the first output end of the measuring module 20; the input end of the second amplifying unit 313 is connected to the first output end of the measuring module 20. It can be understood that the total resistance voltage measured by the measuring module 20 when the reed switch is turned on is input to the amplifying unit 31, and the total resistance voltage is input to the amplifying unit 31. Figure 2 , when the magnet is at the actual position, such as at the third reed switch S3, due to the magnetic strength of the magnet and the sensitivity of the reed switch, the reed switch adjacent to the third reed switch S3 will also be turned on, such as the two reed switches adjacent to the actual position are all turned on, and the reed switches S1-S5 are all turned on at this time. The instrument measures the voltage between T2 and T3, and actually measures the liquid level at the position of S5. At this time, the total resistance voltage when the reed switch is turned on is the voltage of the series circuit composed of R1 to R5; the first voltage V1 output by the amplification unit 31 is equal to the second voltage V2, the first voltage V1 is the uncompensated voltage, and the second voltage V2 is used for the subsequent calculation of the compensation voltage. The obtained compensation voltage and the first voltage V1 are processed by the adder unit 37 to obtain the compensated voltage. Therefore, in some embodiments, the total resistance voltage when the reed switch is turned on can be processed by only one amplification unit 31 to obtain the first voltage V1 and the second voltage V2.

[0053] See also Figure 5 , Figure 5 It is a specific circuit diagram of the subtractor unit 33 in the compensation module 30. In some embodiments, the subtractor unit 33 includes a subtraction circuit 331 and a voltage setting circuit 333. The input end of the voltage setting circuit 333 is connected to the second output end of the measurement module 20, and the output end of the voltage setting circuit 333 is connected to the output end of the subtraction circuit 331.

[0054] In some embodiments, the voltage setting circuit 333 includes an operational amplifier U3A, a resistor R181, a resistor R182, and a sliding rheostat RA4. Assuming that the total resistance when the reed switch is not turned on, that is, the total resistance of the reed chain is 1k, the constant current source driving current is 100uA, and the instrument gain is 10 times, then RA4 should be adjusted so that the output voltage of UA3 is 1000*0.1*10=1000mV. It can be understood that the total resistance voltage when the voltage setting circuit 333 outputs the reed switch is not turned on can be achieved by adjusting the sliding rheostat RA4.

[0055] In some embodiments, the second voltage V2 output by the amplification unit 31 and the voltage output by the voltage setting circuit 333 are input into a subtraction circuit 331. The subtraction circuit 331 includes an operational amplifier U3B, a resistor R174, a resistor R175, a resistor R178, and a resistor R179. The voltage output by the subtractor, i.e., the third voltage V3, is proportional to the number of reed switches that are turned on.

[0056] See also Figure 6 , Figure 6 It is a specific circuit diagram of the ratio setting unit 35 in the compensation module 30, and the ratio setting unit 35 includes: a first resistor R176, a second resistor R177, a sliding rheostat RA5, a first capacitor C150 and an operational amplifier U4A; the output end of the subtractor unit 33 is connected to one end of the first resistor R176, and the other end of the first resistor R176 is connected to the second resistor R177; the other end of the second resistor R177 is connected to the sliding rheostat RA5; the other end of the sliding rheostat RA5 is connected to one end of the first capacitor C150 and grounded; the other end of the first capacitor C150 is connected to the node of the first resistor R176 and the second resistor R177 and to the first input end of the operational amplifier U4A; the second input end of the operational amplifier U4A is connected to the output end of the operational amplifier U4A; the sliding rheostat RA5 is used to set the compensation amount ratio parameter of the compensation module 30. In some embodiments, the ratio setting unit 35 further includes a second capacitor C158. It can be understood that the compensation amount ratio parameter can be adjusted by adjusting the sliding rheostat RA5.

[0057] In certain embodiments, see Figure 6 Combined with Figure 2 , when the magnet is at the actual position, such as at the third reed switch S3, due to the magnetic strength of the magnet and the sensitivity of the reed switch, the reed switch adjacent to the third reed switch S3 will also be turned on, such as the two reed switches adjacent to the actual position are both turned on, and the reed switches S1-S5 are all turned on. At this time, the two reed switches adjacent to the actual position are both turned on, and the compensation amount proportional parameter value can be 0.5. The third voltage V3 output by the subtractor unit 33 is input to the proportional setting unit 35, and the fourth voltage V4, i.e., the compensation value, is output through the proportional adjustment of the proportional setting unit 35. In this way, by using the liquid level meter measurement system of the present invention, the user can adjust the sliding rheostat RA5 of the proportional setting unit 35 according to actual needs to realize the compensation amount proportional parameter, and can better calibrate the compensation value, i.e., the compensation voltage, to obtain a more accurate measurement value.

[0058] In certain embodiments, in the resistive magnetic float level gauge measurement system, the fourth voltage satisfies the following formula:

[0059] V4=(Vt1-Vt2) / 2

[0060] Among them, V4 is the fourth voltage; Vt1 is the total resistance voltage when the reed switch is not turned on; Vt2 is the total resistance voltage when the reed switch is turned on.

[0061] Optionally, the compensation proportional parameter is 0.5. In some embodiments, the compensation proportional parameter can be adjusted according to the relationship between the magnetic steel position and the liquid level position. The ratio is adjustable between 0.25 and 0.75. When the reed switch is symmetrically conductive up and down at the magnetic steel position, the compensation proportional parameter is 0.5.

[0062] In some embodiments, the fourth voltage is the difference between the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on, multiplied by the compensation amount ratio parameter.

[0063] It can be understood that, assuming that the current driving the reed chain is 100uA and the total resistance of the reed chain is 1kΩ, then the voltage on the total resistance when the reed switch is not turned on is Vt1=100uA*1000=100mV; assuming that there are five reed switches turned on, there are 4 resistors short-circuited by the reed switches, and the resistance of each resistor is 10Ω. At this time, the voltage flowing through the total resistance is Vt2=100uA*(1000-10*4)=96mV. At this time, the fourth voltage, i.e. the compensation voltage V4=(Vt1-Vt2) / 2=(100-96) / 2=2mV.

[0064] See also Figure 7 , Figure 7 It is a specific circuit diagram of the adder unit 37 in the compensation module 30. The adder unit 37 includes a resistor R184, a resistor R185, a resistor R186, a resistor R187, an operational amplifier U5A and a capacitor C156. The fourth voltage V4, i.e., the compensation voltage, and the first voltage V1 are input into the adder unit 37. Through the processing of the adder unit 37, the first voltage V1 is compensated to obtain the compensated voltage.

[0065] In some embodiments, the compensated voltage output by the adder unit 37 is input into the circuit conversion module 40. Optionally, the circuit conversion module 40 can be a voltage-to-current converter, which outputs a calibration detection value, i.e., a compensated liquid level height measurement value. The voltage-to-current converter is connected to a display module, such as a liquid crystal display screen. In this way, the user can directly read the calibration detection value, i.e., the compensated liquid level height value, through the liquid crystal display screen.

[0066] See also Figure 8The present invention also provides a resistance type magnetic float liquid level gauge measurement method, the resistance type magnetic float liquid level gauge measurement system comprises a sensor module 10, a measurement module 20 connected to the sensor module 10, a compensation module 30 connected to the measurement module 20, a circuit conversion module 40 connected to the compensation module 30, and the display module connected to the circuit conversion module 40, wherein the sensor module 10 comprises a plurality of resistors, a plurality of reed switches and a magnetic steel, and the resistance type magnetic float liquid level gauge measurement method comprises:

[0067] S10: measuring, by the measuring module 20, the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on;

[0068] S20: inputting the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on into the compensation module 30 to obtain a compensated voltage;

[0069] S30: inputting the compensated voltage into the circuit conversion module 40 to obtain a calibration detection value;

[0070] S40: Displaying the calibration detection value via the display module.

[0071] In this way, by measuring the total resistance voltage when the reed switch is not turned on, and then subtracting it from the total resistance voltage when the reed switch is turned on, a difference, i.e., the third voltage V3, is obtained, and then the difference is proportionally calculated to obtain a compensation voltage, i.e., the fourth voltage V4, and then the compensation voltage is added to the measured voltage, i.e., the total resistance voltage when the reed switch is turned on, to obtain the compensated voltage, thereby realizing the error compensation function and eliminating the influence of the magnetic steel position on the liquid level measurement accuracy.

[0072] Optionally, the compensation module 30 includes an amplification unit 31, a subtractor unit 33, a ratio setting unit 35 and an adder unit 37, and the resistive magnetic float level gauge measurement method includes: inputting the total resistance voltage when the reed switch is not turned on into the amplification unit 31 to obtain the first voltage V1 and the second voltage V2; inputting the second voltage V2 and the total resistance voltage when the reed switch is turned on into the subtractor unit 33 to obtain the third voltage V3; inputting the third voltage V3 into the ratio setting unit 35 to obtain a fourth voltage V4; inputting the first voltage V1 and the fourth voltage V4 into the adder unit 37 to obtain the compensated voltage.

[0073] Optionally, the resistive magnetic float level gauge measurement method further includes setting a compensation amount ratio parameter through the compensation module 30 .

[0074] As described above, the present invention provides a resistive magnetic float liquid level gauge measurement system and method, which combines the sensor module 10, the measurement module 20 and the compensation module 30, and measures the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on through the measurement module 20; the compensation module 30 is controlled to subtract the total resistance voltage when the reed switch is not turned on from the total resistance voltage when the reed switch is turned on to obtain a difference, that is, the third voltage V3, and then the obtained difference is proportionally calculated to obtain a compensation voltage, that is, the fourth voltage V4, and then the compensation voltage is added to the measurement voltage, that is, the total resistance voltage when the reed switch is turned on to obtain the compensated voltage, thereby realizing the function of error compensation and eliminating the influence of the magnetic steel position on the liquid level measurement accuracy.

[0075] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0076] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A resistance type magnetic float level gauge measurement system, It is characterized in that include: A sensor module, wherein the sensor module includes a plurality of resistors, a plurality of reed switches and a magnet; A measuring module, connected to the sensor module, for measuring the total resistance voltage when the reed switch is not turned on, and the total resistance voltage when the reed switch is turned on; A compensation module, the compensation module is used to compensate the total resistance voltage when the reed switch is turned on according to the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on, so as to obtain a compensated voltage; A circuit conversion module, the input end of which is connected to the compensation module to receive the compensated voltage, and the circuit conversion module is used to obtain a calibration detection value; The compensation module includes an amplifying unit, a subtracting unit, a ratio setting unit and an adding unit; the input end of the amplifying unit is connected to the first output end of the measuring module, and is used to receive the total resistance voltage when the reed switch is turned on, so as to obtain a first voltage and a second voltage; the input end of the subtracting unit is connected to the output end of the amplifying unit and the second output end of the measuring module, and is used to receive the second voltage and the total resistance voltage when the reed switch is not turned on, so as to obtain a third voltage; the input end of the ratio setting unit is connected to the output end of the subtracting unit, and is used to receive the third voltage, so as to obtain a fourth voltage; the input end of the adding unit is connected to the output end of the amplifying unit and the output end of the ratio setting unit, and is used to receive the first voltage and the fourth voltage, so as to obtain the compensated voltage; The amplifier of the compensation module includes a first amplifier unit and a second amplifier unit, wherein the input end of the first amplifier unit is connected to the first output end of the measurement module, and is used to receive the total resistance voltage when the reed switch is turned on, so as to obtain a first voltage; The input end of the second amplifying unit is connected to the first output end of the measuring module, and is used to receive the total resistance voltage when the reed switch is turned on, so as to obtain the second voltage; the input end of the subtractor unit is connected to the output end of the second amplifying unit and the second output end of the measuring module, and is used to receive the second voltage and the total resistance voltage when the reed switch is not turned on, so as to obtain the third voltage; the input end of the ratio setting unit is connected to the output end of the subtractor unit, and is used to receive the third voltage, so as to obtain the fourth voltage; the input end of the adder unit is connected to the output end of the first amplifying unit and the output end of the ratio setting unit, and is used to receive the first voltage and the fourth voltage, so as to obtain the compensated voltage; It also includes a display module connected to the output end of the circuit conversion module, and is used to display the liquid level value; The ratio setting unit of the compensation module includes: a first resistor, a second resistor, a sliding rheostat, a first capacitor and an operational amplifier; The output end of the subtractor unit is connected to one end of the first resistor, and the other end of the first resistor is connected to the second resistor; the other end of the second resistor is connected to the sliding rheostat; the other end of the sliding rheostat is connected to one end of the first capacitor and grounded; the other end of the first capacitor is connected to the node of the first resistor and the second resistor and to the first input end of the operational amplifier; the second input end of the operational amplifier is connected to the output end of the operational amplifier; the sliding rheostat is used to set the compensation amount proportional parameter of the compensation module.

2. The resistive magnetic float level gauge measuring system according to claim 1, It is characterized in that The subtractor includes a subtraction circuit and a voltage setting circuit, the input end of the voltage setting circuit is connected to the second output end of the measurement module, and the output end of the voltage setting circuit is connected to the output end of the subtraction circuit.

3. A resistance type magnetic float liquid level gauge measurement method, using the resistance type magnetic float liquid level gauge measurement system as claimed in any one of claims 1 to 2, It is characterized in that The resistive magnetic float level gauge measurement system comprises a sensor module, a measurement module connected to the sensor module, a compensation module connected to the measurement module, a circuit conversion module connected to the compensation module, and a display module connected to the circuit conversion module. The resistive magnetic float level gauge measurement method comprises: The total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on are measured by the measurement module; Inputting the total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on into the compensation module to obtain a compensated voltage; Inputting the compensated voltage into the circuit conversion module to obtain a calibration detection value; The calibration detection value is displayed by the display module.

4. The resistive magnetic float level gauge measurement method as claimed in claim 3, It is characterized in that The compensation module includes an amplification unit, a subtractor unit, a ratio setting unit and an adder unit. The total resistance voltage when the reed switch is not turned on and the total resistance voltage when the reed switch is turned on are input into the compensation module, and obtaining the compensated voltage specifically includes: Inputting the total resistance voltage when the reed switch is not turned on into the amplifying unit to obtain a first voltage and a second voltage; Inputting the second voltage and the total resistance voltage when the reed switch is turned on into the subtractor unit to obtain a third voltage; Inputting the third voltage into the ratio setting unit to obtain a fourth voltage; The first voltage and the fourth voltage are input into the adder unit to obtain the compensated voltage.

5. The resistive magnetic float level gauge measurement method as claimed in claim 4, It is characterized in that Including setting the compensation amount ratio parameter through the compensation module.

6. The resistive magnetic float level gauge measurement method according to claim 4, It is characterized in that The fourth voltage satisfies the following formula: V4=(Vt1-Vt2) / 2 Among them, V4 is the fourth voltage; Vt1 is the total resistance voltage when the reed switch is not turned on; Vt2 is the total resistance voltage when the reed switch is turned on.

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