Ultrasonic Liquid Level Measurement System and Device

Abstract

The present application discloses an ultrasonic liquid level measurement system and device. The ultrasonic liquid level measurement system includes a converter calibration circuit, a transducer calibration circuit, a liquid level measurement control circuit, a transducer, a first contact, and a second contact. One end of the first contact is connected to the liquid level measurement control circuit, and one end of the second contact is connected to the transducer. The converter calibration circuit excites an echo signal analog signal according to the multi-pulse drive signal of the liquid level measurement control circuit. The transducer calibration circuit performs blind zone calibration and sensitivity compensation based on the current blind zone liquid level. When calibrating the converter, the first contact and the converter calibration circuit are turned on, and the liquid level measurement control circuit is connected to the converter calibration circuit through the first contact. When calibrating the transducer, the second contact and the transducer calibration circuit are turned on, and the liquid level measurement control circuit is connected to the transducer calibration circuit through the second contact. Calibration is performed through the converter calibration circuit and the transducer calibration circuit to solve the problems of liquid level measurement deviation and failure.

Description

Technical Field

[0001] The present application relates to the field of liquid measurement technology, and in particular, to an ultrasonic liquid level measurement system and device. Background Art

[0002] With the development of electronic technology, ultrasonic measurement has been widely used in industry and metering instruments due to its high measurement accuracy and lack of pressure loss on the measured fluid. Its measurement principle is mostly based on the transit time method. Ultrasonic level measurement uses a transducer to transmit and receive ultrasonic waves, and the propagation speed of ultrasonic waves in the liquid is used to measure the liquid level.

[0003] However, in actual use, due to factors such as converter offset and transducer aging, the liquid level measurement results of the liquid level measurement module may be offset, the blind area may become larger, and the sensitivity may decrease, resulting in measurement deviation or failure. Summary of the Invention

[0004] The purpose of this application is to provide an ultrasonic liquid level measurement system and device to solve the problems of aging and deviation of liquid level measurement results in existing ultrasonic liquid level measurement.

[0005] In order to solve the above problems, this application adopts the following technical solutions:

[0006] A first aspect of the present application provides an ultrasonic liquid level measurement system, comprising: a converter calibration circuit, a transducer calibration circuit, a liquid level measurement control circuit, a transducer, a first contact, and a second contact, wherein one end of the first contact is connected to the liquid level measurement control circuit, and one end of the second contact is connected to the transducer. The converter calibration circuit is configured to excite an echo signal simulation signal according to a multi-pulse drive signal from the liquid level measurement control circuit to simulate an echo signal with a fixed transit time. The transducer calibration circuit is configured to perform blind spot calibration and sensitivity compensation based on a current blind spot liquid level. When performing liquid level measurement, one end of the first contact and one end of the second contact are conductively connected, and the liquid level measurement control circuit is connected to the transducer. When performing converter calibration, one end of the first contact and the converter calibration circuit are conductively connected, and the liquid level measurement control circuit is connected to the converter calibration circuit via the first contact. When performing transducer calibration, one end of the second contact and the transducer calibration circuit are conductively connected, and the liquid level measurement control circuit is connected to the transducer calibration circuit via the second contact.

[0007] Further, the converter calibration circuit includes an AND gate, a first flip-flop, a second flip-flop, and an ultrasonic signal source. The output end of the second flip-flop and the ultrasonic signal source are both connected to the input end of the AND gate. The input end of the first flip-flop is connected to the signal input end, and the output end of the first flip-flop is connected to the input end of the second flip-flop.

[0008] Further, the converter calibration circuit includes a first RC circuit. One end of the first RC circuit is connected to the output end of the AND gate, and one end of the first RC circuit is connected to the signal output end.

[0009] Further, the converter calibration circuit includes a first delay circuit and a second RC circuit. The first delay circuit is respectively connected to two pins of the first contact and the first flip-flop. One end of the first delay circuit is connected to electricity, and the other end of the first delay circuit is grounded. The second RC circuit is respectively connected to the signal input end and the first flip-flop.

[0010] Further, the converter calibration circuit includes a diode. Two ends of the diode are respectively connected to the second RC circuit and the signal input end.

[0011] Further, the converter calibration circuit includes a second delay circuit. The second delay circuit is respectively connected to two pins of the second flip-flop. One end of the second delay circuit is connected to electricity, and the other end of the second delay circuit is grounded.

[0012] Further, the sensitivity of the transducer satisfies the following relationship:

[0013] Ar = Ar max *G*α;

[0014] Where, Ar is the signal amplitude, Ar max is the peak-to-peak value of the output signal of the transducer, G is the signal amplification factor, and α is the signal sensitivity calibration coefficient.

[0015] This application also provides an ultrasonic liquid level measurement device, and the ultrasonic liquid level measurement device includes the ultrasonic liquid level measurement system described in any one of the above.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: By using the converter calibration circuit and the transducer calibration circuit in cooperation, the measurement deviation caused by factors such as the aging of the converter and the transducer can be effectively eliminated, the deviation of the converter and the transducer can be automatically calibrated, thereby improving the accuracy of liquid level measurement; at the same time, the blind area of the liquid level measurement module is automatically calibrated, and the sensitivity of the transducer is compensated. Description of the Drawings

[0017] Figure 1It is a system diagram of an ultrasonic liquid level measurement system;

[0018] Figure 2 It is a schematic diagram of a converter calibration circuit;

[0019] Figure 3 It is a circuit diagram of a converter calibration circuit;

[0020] Figure 4 It is a schematic diagram of the echo generated by the converter calibration circuit; and

[0021] Figure 5 It is a schematic diagram of the liquid level measurement by the ultrasonic liquid level measurement system. Specific embodiments

[0022] The following will describe the specific embodiments of the present application in detail with reference to the accompanying drawings.

[0023] It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other. The detailed description in the specific embodiments should be understood as an explanatory illustration of the purpose of the present application and should not be regarded as an improper limitation of the present application.

[0024] It should be understood that the orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings. These orientation terms are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0025] Figure 1 1 is a system diagram of an ultrasonic liquid level measurement system, 2 is a schematic diagram of a converter calibration circuit, Figure 3 3 is a circuit diagram of a converter calibration circuit, Figure 4 4 is a schematic diagram of the echo generated by the converter calibration circuit, Figure 5 5 is a schematic diagram of the liquid level measurement by the ultrasonic liquid level measurement system. As Figures 1 to 5As shown in the figure, an embodiment of the present application provides an ultrasonic liquid level measurement system, including: a converter calibration circuit 100, a transducer calibration circuit 200, a liquid level measurement control circuit 300, a transducer 400, a first contact J1 and a second contact J2. One end of the first contact J1 is connected to the liquid level measurement control circuit 300, and one end of the second contact J2 is connected to the transducer 400. The converter calibration circuit 100 is configured to excite an echo signal analog signal according to the multi-pulse drive signal of the liquid level measurement control circuit 300 to simulate an echo signal with a fixed transit time. The transducer calibration circuit 200 is configured to perform blind zone calibration and sensitivity compensation based on the current blind zone liquid level. Wherein, when performing liquid level measurement, one end of the first contact J1 and one end of the second contact J2 are conducted, and the liquid level measurement control circuit 300 is connected to the transducer 400; when performing converter calibration, one end of the first contact J1 and the converter calibration circuit 200 are conducted, and the liquid level measurement control circuit 300 is connected to the converter calibration circuit 200 through the first contact J1; when performing transducer calibration, one end of the second contact J2 and the transducer calibration circuit 200 are conducted, and the liquid level measurement control circuit 300 is connected to the transducer calibration circuit 200 through the second contact J2.

[0026] Specifically, the converter calibration circuit 100 generates a multi-pulse drive signal and generates an analog echo signal according to the multi-pulse drive signal. The transit time of the analog echo signal is set to a fixed value to simulate a real echo signal. The transducer calibration circuit 200 includes a blind zone calibration module and a sensitivity compensation module. The blind zone calibration module performs calibration according to the current blind zone liquid level to eliminate the measurement deviation caused by the blind zone. The sensitivity compensation module performs sensitivity compensation according to the aging degree of the transducer to improve the measurement accuracy. The liquid level measurement control circuit 300 is responsible for controlling the operation of the entire liquid level measurement system, processing signals from the transducer, and controlling the operation of the converter calibration circuit 100 and the transducer calibration circuit 200. The first contact J1 and the second contact J2: These two contacts are used to connect the liquid level measurement control circuit 300, the converter calibration circuit 100 and the transducer calibration circuit 200. When performing liquid level measurement, one end of the first contact J1 and one end of the second contact J2 are conducted, and the liquid level measurement control circuit 300 is connected to the transducer 400. When performing converter calibration, one end of the first contact J1 and the converter calibration circuit 100 are conducted, and the liquid level measurement control circuit 300 is connected to the converter calibration circuit 100 through the first contact J1. When performing transducer calibration, one end of the second contact J2 and the transducer calibration circuit 200 are conducted, and the liquid level measurement control circuit 300 is connected to the transducer calibration circuit 200 through the second contact J2.

[0027] It should be noted that, by the combined use of the converter calibration circuit and the transducer calibration circuit, the measurement deviation caused by factors such as the aging of the converter and the transducer can be effectively eliminated, the deviations of the converter and the transducer can be automatically calibrated, thereby improving the accuracy of liquid level measurement; at the same time, the blind area of the liquid level measurement module is automatically calibrated, and the sensitivity of the transducer is compensated.

[0028] In some embodiments, the converter calibration circuit 100 includes an AND gate 101, a first flip - flop 102, a second flip - flop 103, and an ultrasonic signal source 104. The output end of the second flip - flop J2 and the ultrasonic signal source 104 are both connected to the input end of the AND gate 101. The input end of the first flip - flop J1 is connected to the signal input end, and the output end of the first flip - flop 102 is connected to the input end of the second flip - flop 103.

[0029] Specifically, the AND gate 101 receives the output signal of the second flip - flop 103 and the signal of the ultrasonic signal source 104, and performs a logical AND operation on these two signals. For example, when both input signals are at a high level, the output signal of the AND gate is at a high level, otherwise it is at a low level. The first flip - flop 102 receives the signal at the signal input end (ultrasonic transmission signal Pul_1). The second flip - flop 103 receives the output signal of the first flip - flop 102, converts it into an analog echo signal, and the transit time of the analog echo signal is set to a fixed value to simulate a real echo signal. The ultrasonic signal source 104 generates an ultrasonic signal. The frequency and intensity of the ultrasonic signal can be adjusted as needed.

[0030] For example, the trigger signal (Pul_1) is input to the first flip - flop 102. The first flip - flop 102 outputs an echo delay timing, and the second flip - flop 103 outputs an echo pulse width timing. After the echo pulse width timing and the signal of the ultrasonic signal source 104 pass through the AND gate 101, an echo timing is output.

[0031] In some embodiments, the converter calibration circuit 100 includes a first RC circuit 105. One end of the first RC circuit 105 is connected to the output end of the AND gate 101, and one end of the first RC circuit 105 is connected to the signal output end.

[0032] Specifically, the first RC circuit 105 includes resistors R5, R6 and capacitors C4, C5. The first RC circuit 105 performs filtering and noise reduction. Among them, one end of the first RC circuit 105 is connected to the output end of the AND gate 101, and the other end is connected to the signal output end Vout. The AND gate 101 is used to receive the output signal of the second flip - flop 103 and the signal of the ultrasonic signal source 104, and perform a logical AND operation on these two signals. For example, when both input signals are at a high level, the output signal of the AND gate is at a high level, otherwise it is at a low level.

[0033] In some embodiments, the converter calibration circuit includes a first delay circuit 106 and a second RC circuit 107. The first delay circuit 106 is respectively connected to two pins of the first contact J1 and the first flip-flop 102. One end of the first delay circuit 106 is connected to power, and the other end of the first delay circuit 106 is grounded. The second RC circuit 107 is respectively connected to the signal input terminal and the first flip-flop 102.

[0034] Specifically, the first delay circuit 106 is used to generate a delay signal to control the operation of the first flip-flop 102. The first delay circuit 106 is respectively connected to two pins of the first contact J1 and the first flip-flop 102, with one end connected to power and the other end grounded. The first flip-flop 102 receives the signal (Pul_1) from the signal input terminal. The second RC circuit 107 includes a resistor R3 and a capacitor C2, and the second RC circuit 107 is respectively connected to the signal input terminal and the first flip-flop 102.

[0035] In some embodiments, the converter calibration circuit 100 includes a diode 108, and two ends of the diode 108 are respectively connected to the second RC circuit 107 and the signal input terminal.

[0036] Specifically, the diode 108 is used to protect the circuit from overvoltage impact and ensure the correct transmission of the signal. Two ends of the diode 108 are respectively connected to the second RC circuit 107 and the signal input terminal, so that the signal (Pul_1) can only be transmitted from the signal input terminal through the second RC circuit 107 to the first flip-flop 102.

[0037] In some embodiments, the converter calibration circuit includes a second delay circuit 109. The second delay circuit 109 is respectively connected to two pins of the second flip-flop 103. One end of the second delay circuit 109 is connected to power, and the other end of the second delay circuit 109 is grounded.

[0038] Specifically, the second delay circuit 109 is used to generate a delay signal to control the operation of the second flip-flop 103. The second delay circuit 109 is respectively connected to two pins of the second flip-flop 103, with one end connected to power and the other end grounded. The second flip-flop 103 is used to receive the output signal of the second delay circuit 109. The converter calibration circuit 100 generates a delay signal to control the operation of the second flip-flop 103. The delay signal can ensure that the second flip-flop 103 is triggered at the correct time point, thereby generating a stable multi-pulse drive signal. Among them, by adjusting the resistor R4 and the capacitance value C3 of the second delay circuit 109, the delay time of the delay signal can be adjusted to adapt to different calibration requirements.

[0039] For a better understanding of the converter calibration circuit 100, the following is combined with Figure 3The principle of the converter calibration circuit 100 is described.

[0040] The ultrasonic transmission signal Pul_1 is connected to the positive node of D1. The negative terminal node of D1 is connected to the upper ends of R3 and C2. The lower ends of R3 and C2 are grounded. The upper ends of R3 and C2 are connected to the input terminal of pin 2 of the trigger 1. The pin 7 of the trigger 1 (the first trigger 102) is connected to the delay resistor R1 and the delay capacitor C1. The other end of the delay resistor R1 is connected to the power supply. One end of the delay capacitor C1 is grounded. The output of pin 5 of the trigger 1 (the first trigger 102) is connected to the input terminal of pin 2 of the trigger 2. The pin 7 of the trigger 2 (the second trigger 103) is connected to the delay resistor R4 and the delay capacitor C3. The other end of the delay resistor R4 is connected to the power supply. One end of the delay capacitor C3 is grounded. The output of pin 5 of the trigger 2 (the second trigger 103) is connected to the input terminal of pin 2 of the logic AND gate (AND gate 101). The other input terminal of pin 1 of the logic AND gate (AND gate 101) is connected to the ultrasonic signal source. The output of pin 4 of the logic AND gate is connected to the upper end of the capacitor C4. The other end of the capacitor C4 is connected to R5. The other end of R5 is connected to the parallel connection of C5 and R6. The other ends of C5 and R6 are grounded. The upper end node of C5 and R6 outputs an analog ultrasonic echo signal containing the transit delay. The converter calibration circuit 100 generates a standard echo signal with a fixed echo time, width, and amplitude through the ultrasonic transmission timing, and inputs it to the input terminal of the ultrasonic amplification circuit, thereby generating a fixed transit time calibration signal without the influence of the transducer.

[0041] In the actual circuit for transducer calibration, a single-pulse drive circuit is used to complete the transducer blind zone calibration. This is because a single pulse has a lower blind zone, so as to obtain the information of the blind zone offset in advance and perform the blind zone calibration in a timely manner.

[0042] According to the principle, the phenomenon caused by the decrease in the transducer sensitivity is that the echo amplitude decreases, which may cause the measurement value to deviate or be lost. Therefore, it is necessary to compensate the transducer sensitivity to improve the module stability. In this application, the second contact J2 is used to switch to the sensitivity detection circuit and the single-pulse drive circuit to specifically calculate and implement.

[0043] In some embodiments, the sensitivity of the transducer satisfies the following relationship:

[0044] Ar = Ar max *G*α;

[0045] Where, Ar is the signal amplitude, Ar max is the peak-to-peak value of the output signal of the transducer, G is the signal amplification factor, and α is the signal sensitivity calibration coefficient.

[0046] Specifically, since the single-pulse driving circuit used is a quantitative ultrasonic transmission driving circuit, a quantitative transmission signal can be obtained. The sensitivity detection circuit can detect the amplitude of the echo and quantitatively analyze the signal intensity through the echo amplitude. By combining the two, the sensitivity of the transducer can be quantified.

[0047] For example, when the instrument leaves the factory, the amplitude of the echo signal output by the amplifier circuit is As, and the peak-to-peak value of the signal output by the transducer is As max , and the signal amplification factor is G. After the customer uses it, the amplitude of the echo signal output by the amplifier circuit is Ar, and the peak-to-peak value of the signal output by the transducer is Ar max . The signal sensitivity calibration coefficient is α. It can be seen that the factory sensitivity As = As max *G, and the sensitivity Ar after the customer uses it = Ar max *G*α. When the amplitude of Ar max decreases, we need to adjust the value of the sensitivity calibration coefficient α to make As = Ar. Suppose Ar max decreases to 0.9 times of that when it leaves the factory, then G needs to be updated to 1 / 0.9 = 1.11 times of the original to compensate for the reduced sensitivity of the transducer.

[0048] To better understand the ultrasonic liquid level measurement system of the embodiments of the present application, the following specifically describes each part of the ultrasonic liquid level measurement system.

[0049] The ultrasonic liquid level measurement system can perform self-calibrated liquid level measurement, thereby realizing the self-calibration function of ultrasonic measurement. The ultrasonic liquid level measurement system includes a converter calibration circuit 100 and a transducer calibration circuit 200, combined with a liquid level measurement control circuit 300 and a transducer 400, thereby realizing self-calibrated liquid level measurement.

[0050] Among them, the converter calibration circuit 100 stimulates an echo signal analog signal according to the multi-pulse driving signal of the liquid level measurement control circuit 300, and simulates an echo signal with a fixed transit time. The converter calibration circuit 100 consists of a trigger 1 (the first trigger 102), a trigger 2 (the second trigger 103), an ultrasonic signal source 104, and a logical AND gate (AND gate 101). The converter calibration circuit 100 generates a standard echo signal with a fixed echo time, width, and amplitude through the ultrasonic transmission timing, and inputs it to the input end of the ultrasonic amplifier circuit, thereby generating a fixed transit time calibration signal without the influence of the transducer.

[0051] The principle of the converter calibration circuit 100 is as follows. The ultrasonic transmission signal Pul_1 is connected to the positive node of D1. The negative terminal node of D1 is connected to the upper ends of R3 and C2. The lower ends of R3 and C2 are grounded. The upper ends of R3 and C2 are connected to the input terminal of pin 2 of the trigger 1 (the first trigger 102). The pin 7 of the trigger 1 (the first trigger 102) is connected to the delay resistor R1 and the delay capacitor C1. The other end of the delay resistor R1 is connected to the power supply. One end of the delay capacitor C1 is grounded. The output of pin 5 of the trigger 1 is connected to the input terminal of pin 2 of the trigger 2 (the second trigger 103). The pin 7 of the trigger 2 (the second trigger 103) is connected to the delay resistor R4 and the delay capacitor C3. The other end of the delay resistor R4 is connected to the power supply. One end of the delay capacitor C3 is grounded. The output of pin 5 of the trigger 2 is connected to the input terminal of pin 2 of the logical AND gate (AND gate 101). The other input terminal of pin 1 of the logical AND gate (AND gate 101) is connected to the ultrasonic signal source. The output of pin 4 of the logical AND gate is connected to the upper end of the capacitor C4. The other end of the capacitor C4 is connected to R5. The other end of R5 is connected to the parallel connection of C5 and R6. The other ends of C5 and R6 are grounded. The upper node of C5 and R6 outputs an analog ultrasonic echo signal containing the transit delay.

[0052] The transducer calibration circuit 200 is used for blind zone calibration and sensitivity compensation at the current blind zone liquid level. The method of blind zone calibration is to use a single pulse with a smaller blind zone to drive the transducer to verify the current blind zone offset for calibration. Sensitivity compensation is to use a single pulse to drive the transducer, detect the amplitude of the echo signal to quantitatively analyze the transducer sensitivity, and combine with the PGA gain adjustment circuit to compensate for the gain.

[0053] When the circuit is in the working mode, the liquid level measurement control circuit 300 is connected to the transducer 400 through the normally closed contacts of the first contact J1 and the second contact J2 to perform the conventional liquid level measurement function.

[0054] When the circuit is in the converter calibration mode, the first contact J1 is actuated to disconnect the normally closed contact and close the normally open contact, so that the liquid level measurement control circuit 300 is connected to the converter calibration circuit 100.

[0055] When the circuit is in the transducer blind zone calibration mode, the second contact J2 is actuated to disconnect the normally closed contact and close the normally open contact, so that the liquid level measurement control circuit 300 is connected to the transducer 400 calibration circuit, and the single pulse drive circuit of the transducer calibration circuit 200 is used to drive the transducer.

[0056] When the circuit is in the transducer sensitivity compensation mode, the second contact J2 is actuated to disconnect the normally closed contact and close the normally open contact, so that the liquid level measurement control circuit 300 is connected to the transducer calibration circuit 200, the single pulse drive circuit of the transducer calibration circuit 200 is used to drive the transducer 400, and the peak gain detection circuit is used to detect the signal amplitude.

[0057] It should be noted that in the ultrasonic liquid level measurement system of the embodiments of the present application, the transducer is matched by adjusting the driving frequency, the sensitivity is compensated by adjusting the echo amplification factor, the transducer is driven quantitatively by a single pulse, a sensitivity detection circuit is used to quantify the intensity of the ultrasonic echo signal, and the ultrasonic blind zone calculation formula hb = d 2 / 4λ is used to derive and adjust the blind zone value, so that the deviation of the converter can be automatically calibrated, the blind zone of the liquid level measurement module can be automatically calibrated, the sensitivity of the transducer can be automatically compensated, and the frequency of the transducer can be automatically matched.

[0058] The present application also provides an ultrasonic liquid level measuring device, and the ultrasonic liquid level measuring device includes the ultrasonic liquid level measurement system described in any one of the above.

[0059] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions required to be protected by the present application.

Claims

1. An ultrasonic liquid level measurement system, characterized in that: include: A converter calibration circuit, a transducer calibration circuit, a liquid level measurement control circuit, a transducer, a first contact and a second contact, wherein one end of the first contact is connected to the liquid level measurement control circuit, and one end of the second contact is connected to the transducer. The converter calibration circuit is used to excite an echo signal simulation signal according to a multi-pulse drive signal of the liquid level measurement control circuit to simulate an echo signal with a fixed transit time. The transducer calibration circuit is used to perform blind spot calibration and sensitivity compensation based on the current blind spot liquid level. When liquid level measurement is performed, one end of the first contact and one end of the second contact are conductive, and the liquid level measurement control circuit is connected to the transducer; when converter calibration is performed, one end of the first contact and the converter calibration circuit are conductive, and the liquid level measurement control circuit is connected to the converter calibration circuit through the first contact; when transducer calibration is performed, one end of the second contact and the transducer calibration circuit are conductive, and the liquid level measurement control circuit is connected to the transducer calibration circuit through the second contact.

2. The ultrasonic liquid level measurement system according to claim 1, characterized in that: The converter calibration circuit includes an AND gate, a first trigger, a second trigger and an ultrasonic signal source. The output end of the second trigger and the ultrasonic signal source are both connected to the input end of the AND gate, the input end of the first trigger is connected to the signal input end, and the output end of the first trigger is connected to the input end of the second trigger.

3. The ultrasonic liquid level measurement system according to claim 2, characterized in that: The converter calibration circuit includes a first RC circuit, one end of the first RC circuit is connected to the output end of the AND gate, and one end of the first RC circuit is connected to the signal output end.

4. The ultrasonic liquid level measurement system according to claim 2, characterized in that: The converter calibration circuit includes a first delay circuit and a second RC circuit, the first delay circuit is respectively connected to the first contact and the two pins of the first trigger, one end of the first delay circuit is connected to electricity, and the other end of the first delay circuit is grounded, and the second RC circuit is respectively connected to the signal input end and the first trigger.

5. The ultrasonic liquid level measurement system according to claim 4, characterized in that: The converter calibration circuit includes a diode, and two ends of the diode are respectively connected to the second RC circuit and the signal input end.

6. The ultrasonic liquid level measurement system according to claim 2, characterized in that: The converter calibration circuit includes a second delay circuit, which is respectively connected to two pins of the second trigger, one end of the second delay circuit is connected to power, and the other end of the second delay circuit is grounded.

7. The ultrasonic liquid level measurement system according to claim 2, characterized in that: The sensitivity of the transducer satisfies the following relationship: Ar−Ar max *G*α; Among them, Ar is the signal amplitude, Ar max is the peak-to-peak value of the transducer output signal, G is the signal amplification factor, and α is the signal sensitivity calibration coefficient.

8. An ultrasonic liquid level measuring device, characterized in that: The ultrasonic liquid level measuring device comprises the ultrasonic liquid level measuring system according to any one of claims 1 to 7.

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