Metering pump flow calibration device in radiation environment and control method thereof

Abstract

The invention discloses a flow calibration device of a pump body, and aims to provide a metering pump flow calibration device in a radioactive environment, which is high in detection precision, strong in universality, high in automation degree and capable of accurately measuring the liquid level height in the radioactive environment, and a control method of the metering pump flow calibration device. According to the technical scheme, air can be evenly blown into a first air blowing pipe and a second air blowing pipe through a constant flow device, the air pressure in the air blowing pipes is larger than the static pressure of a liquid column at the lower ends of the air blowing pipes, and the constant flow device in the air blowing pipes limits the supplemented air amount in the pipes, so that the air blowing pipe pressure displayed on a differential pressure transmitter is the static pressure of the liquid column. The static pressure value is used for calculating the pressure difference through the static pressure and the liquid level height according to a pressure difference method, the accuracy of the detection result is high, the measuring structure and the radioactive substance are buried underground synchronously, harm of the radioactive substance to workers is avoided, safety is high, and the pump flow calibration device is suitable for the technical field of pump flow calibration.

Description

Technical Field

[0001] The present invention relates to a flow calibration device for a pump body, and more particularly to a flow calibration device for a metering pump in a radiation environment. Background Art

[0002] The flow calibration device for a metering pump is a device used to accurately measure the flow rate of liquid delivered by a metering pump per unit time. It generally has a container of sufficient capacity and a liquid level meter installed in the container. It can measure the liquid level based on the relationship between the liquid pressure and the liquid level height. It has a simple structure and high reliability. Pipes and valves are installed at the metering pump, and the flow rate in the pipeline is detected by a flow meter for easy calculation. The above-mentioned flow calibration device is widely used in chemical production, pharmaceutical and water treatment industries to ensure the accuracy of the proportion of additives in the detected liquid.

[0003] In some radioactive environments, flow calculation is required. However, in radioactive environments, conventional metering pump flow calibration devices will be affected by radiation, resulting in degradation of component performance, inaccurate measurements, or even damage. At the same time, for production safety, radioactive objects are usually buried deep underground, making it impossible for workers to observe flow at close range, resulting in measurement errors. Therefore, special design of the device is required to ensure safe and accurate flow calibration in radioactive environments. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a flow calibration device and a control method for a metering pump in a radioactive environment, which has high detection accuracy, strong versatility, high degree of automation, and can accurately measure the liquid level height in a radioactive environment.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a flow calibration device for a metering pump in a radiation environment, characterized in that it includes a calibration tank body, a blowing device is provided on the top of the calibration tank body, the blowing device includes a first blowing pipe, a second blowing pipe, a differential pressure transmitter and an air pump, the first blowing pipe, the second blowing pipe, the differential pressure transmitter and the air pump are connected by a rubber pipe, the first blowing pipe extends to the bottom of the calibration tank body and leaves a gap with at least the bottom of the calibration tank body for passing liquid, a metering pump inlet and a metering pump overflow outlet are provided on the side wall of the calibration tank body, and an emptying port is also provided at the bottom of the calibration tank body, and the differential pressure transmitter is used to calibrate the flow of the metering pump.

[0006] The present invention is further configured as follows: the height of the metering pump inlet on the side wall of the calibration tank is less than the height of the metering pump outlet on the side wall of the calibration tank, and the height of the bottom of the second air blowing pipe inside the calibration tank is greater than the height of the metering pump outlet on the side wall of the calibration tank.

[0007] The present invention is further configured as follows: the metering pump inlet, the metering pump overflow outlet and the emptying port circulate in the device through a pipeline, and a pump body is further provided at the lower end of the emptying port.

[0008] The present invention is further configured as follows: a constant flow device is also provided on the rubber connecting pipe between the air pump and the first and second air blowing pipes, and the constant flow device is configured to allow the first air blowing pipe and the second air blowing pipe to exhaust air evenly.

[0009] Preferably, the calibration tank, the first air blowing pipe, the second air blowing pipe, the constant flow device, the air pump and the differential pressure transmitter are buried deep underground.

[0010] The present invention also provides a control method for a flow calibration device of a metering pump in a radiation environment, wherein a liquid level sensor is provided in each of the first air blowing pipe and the second air blowing pipe, and a control center is provided on the differential pressure transmitter, wherein the liquid level sensor is used to detect the liquid level state in the first air blowing pipe and the second air blowing pipe, and the control center is used to calculate the pressure difference data and display the calculation result on the pressure difference transmitter, and the control method comprises the following steps: S1, sealing the emptying port of the device to prevent the metering pump medium from leaking from the emptying port;

[0011] S2, the metering pump inlet is opened and the metering pump medium is introduced, and at the same time the air pump ventilates the first and second air blowing pipes, and the air stabilizing valve is used to ensure the smooth air output, and the ventilation time is T1;

[0012] S3. After the T1 period, the differential pressure transmitter detects the liquid levels of the first air blowing pipe and the second air blowing pipe, and the detection results are H1 and H2 respectively;

[0013] S4, calculating the pressure difference between the first air blowing pipe and the second air blowing pipe through H1 and H2, and recording the current pressure difference;

[0014] S5, continue to introduce the metering pump medium, and ventilate the first air blowing pipe and the second air blowing pipe again, and the ventilation time is T2;

[0015] S6. After the T2 period, the liquid levels of the first air blowing pipe and the second air blowing pipe are detected again, and the detection results are H3 and H4 respectively;

[0016] S7, calculate the pressure difference between the first air blowing pipe and the second air blowing pipe again through H3 and H4, and record the pressure difference;

[0017] S8. Perform flow calibration calculation based on the twice measured pressure difference, and upload the calculation result to the control center, and perform flow calibration calculation through the control center.

[0018] Preferably, in steps S4 and S7, the pressure difference is calculated as:

[0019] (1)

[0020] in, is the pressure difference between the first blowing pipe and the second blowing pipe, is the density of the metering pump medium liquid, is the acceleration due to gravity, It is the measured liquid level in the current calibration tank.

[0021] Preferably, the step S5 also includes an overflow detection of the calibration tank, including the following steps: S51, the overflow outlet of the metering pump detects whether there is liquid passing through it. If so, it is determined that too much medium is currently passed into the metering pump, and the liquid level reaches the overflow outlet of the metering pump and overflows. The device stops ventilation and opens the emptying port to allow the metering pump medium to be discharged from the emptying port. Otherwise, it is determined that the liquid level in the calibration tank is normal and the device continues to operate.

[0022] Preferably, the control method further includes an emptying control of the calibration tank, comprising the following steps: S9, before the metering pump medium is introduced, opening the device emptying port, and simultaneously closing the metering pump medium inlet and the metering pump medium outlet;

[0023] S10, continue to ventilate the first air blowing tube and the second air blowing tube, and the ventilation time is T3;

[0024] S11, after the T3 time period, the ventilation is stopped, and the device detects whether there is liquid in the air blowing pipe. If so, it is determined that there is liquid in the calibration tank, and the device jumps back to S10 for re-detection. Otherwise, it is determined that there is no liquid in the current calibration tank, and jumps to S12 for further detection;

[0025] S12, the device opens the medium inlet and the medium outlet of the metering pump, and closes the device drain port for subsequent testing.

[0026] By adopting the above technical scheme, the beneficial effects are as follows: 1. By providing an air blowing device on the top of the calibration tank body, the air blowing device includes a first air blowing pipe, a second air blowing pipe, a differential pressure transmitter and an air pump, and a constant flow device is provided between the air pump and the first and second air blowing pipes. By adopting the above setting scheme, air can be evenly blown into the first and second air blowing pipes through the constant flow device. At the same time, since a metering pump medium for measurement is provided inside the calibration tank body, the metering pump medium exists in the portion of the air blowing pipe located at the bottom of the liquid surface. At the same time, when blowing, the air pressure in the air blowing pipe is greater than the liquid pressure at the lower end of the air blowing pipe. Column static pressure, gas bubbles out from the lower end of the air blowing pipe, and because the constant flow device in the air blowing pipe limits the amount of supplementary gas in the pipe, the air blowing pipe pressure displayed on the differential pressure transmitter is the static pressure of the liquid column. The static pressure value is used to calculate the pressure difference according to the pressure difference method through static pressure and liquid level height, and the result is uploaded to the control center. The measurement workpiece structure of the pressure difference and flow is compact, the span between each structure is small, the detection result is highly accurate, and the measurement structure is buried underground synchronously with the radioactive items, avoiding the harm of radioactive substances to the staff, and the safety is high.

[0027] 2. Furthermore, in the process of adding metering pump medium into the calibration tank body and in the process of ventilation detection on the air blowing pipe, in order to avoid overflow of the metering pump medium in the calibration tank body, the height of the metering pump inlet on the side wall of the calibration tank body is less than the height of the metering pump outlet on the side wall of the calibration tank body. When the metering pump medium is added into the calibration tank body through the metering pump inlet, it is effectively prevented that the metering pump medium is added too much, thereby causing the metering pump to overflow out of the top of the calibration tank body. At the same time, the height of the bottom of the second air blowing pipe inside the calibration tank body is greater than the height of the metering pump outlet on the calibration tank body, which effectively prevents the metering pump medium from entering the second air blowing pipe, preventing the liquid from affecting the second air blowing pipe and reducing the detection accuracy. In addition, the present application can also simultaneously perform overflow detection on the calibration tank body during the process of flow detection. Specifically, when liquid passes through the overflow outlet of the calibration tank body, it means that there is too much metering pump medium in the calibration tank body. If the detection is continued, the accuracy of the result will be poor, and the metering pump medium in the calibration tank body needs to be discharged.

[0028] 3. At the same time, in order to improve the accuracy of the detection, it is necessary to ensure the stability and uniformity of the ventilation process when the air blowing pipe is ventilated. A constant flow device is provided between the pump body and the air blowing pipe. The constant flow device is used to limit the air flow passing through so as to ensure uniform ventilation of the first and second air blowing pipes, and prevent the pressure value from changing and causing measurement errors. In the detection process, the pressure difference method is used to measure the flow rate. Specifically, the measurement formula of the pressure difference method is: ,in, is the pressure difference between the first air blowing pipe and the second air blowing pipe to be measured, To calibrate the density of the metering pump medium in the tank, is the current gravitational acceleration, For the measured liquid level, the liquid level of the blowing pipe can be conveniently obtained during the ventilation of the blowing pipe, so that the pressure difference can be calculated, and the detection is convenient. At the same time, by repeatedly introducing the metering pump medium and blowing the first and second blowing pipes, the pressure difference can be detected, the accuracy of the detection result is improved, and the detection effect is good.

[0029] 4. In addition, before the flow test, the calibration tank needs to be emptied to prevent the presence of liquid in the calibration tank, thereby reducing the accuracy of the test. The inside of the calibration tank needs to be emptied and tested before the test starts and after the test is completed. Specifically, if there is liquid residue in the calibration tank, the actual volume of liquid involved in the calibration will be less than the theoretical calculation during the test. Therefore, it is necessary to keep the inside of the calibration tank dry. After the calibration tank is emptied, gas is continuously introduced into the calibration tank to ensure that the inside of the calibration tank is dry, thereby improving the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the specific structure of an embodiment of a flow calibration device for a metering pump in a radiation environment and a control method thereof according to the present invention;

[0031] Figure 2 It is a flow chart of a control method of an embodiment of a flow calibration device for a metering pump in a radiation environment and a control method thereof of the present invention;

[0032] Figure 3 It is a flow chart of an overflow detection method for a calibration tank according to an embodiment of a flow calibration device and a control method thereof for a metering pump in a radiation environment of the present invention;

[0033] Figure 4 It is a flow chart of emptying control of a calibration tank according to an embodiment of a flow calibration device and a control method thereof for a metering pump in a radiation environment of the present invention;

[0034] Reference numerals in the figure: 1. calibration tank; 21. first air blowing pipe; 22. second air blowing pipe; 23. differential pressure transmitter; 24. air pump; 25. rubber connecting pipe; 3. metering pump inlet; 4. metering pump overflow outlet; 5. drain port; 6. pump body; 7. constant flow device. DETAILED DESCRIPTION

[0035] Reference Figures 1 to 4 The present invention further describes an embodiment of a flow calibration device for a metering pump in a radiation environment and a control method thereof.

[0036] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to illustrate the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "on" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0037] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0038] A flow calibration device for a metering pump in a radiation environment, characterized in that it includes a calibration tank body 1, a blowing device is provided on the top of the calibration tank body 1, the blowing device includes a first blowing pipe 21, a second blowing pipe 22, a differential pressure transmitter 23 and an air pump 24, the first blowing pipe 21, the second blowing pipe 22, the differential pressure transmitter 23 and the air pump 24 are connected by a rubber pipe 25, the first blowing pipe 21 extends to the bottom of the calibration tank body 1 and leaves a gap with at least the bottom of the calibration tank body 1 for passing liquid, a metering pump inlet 3 and a metering pump overflow outlet 4 are provided on the side wall of the calibration tank body 1, and an emptying port 5 is also provided at the bottom of the calibration tank body 1, and the differential pressure transmitter 23 is used to calibrate the flow of the metering pump.

[0039] The height of the metering pump inlet 3 on the side wall of the calibration tank body 1 is less than the height of the metering pump outlet on the side wall of the calibration tank body 1, and the height of the bottom of the second air blowing pipe 22 inside the calibration tank body 1 is greater than the height of the metering pump outlet on the side wall of the calibration tank body 1.

[0040] The metering pump inlet 3, the metering pump overflow outlet 4 and the drain port 5 circulate in the device through pipelines, and a pump body 6 is further provided at the lower end of the drain port 5.

[0041] A constant flow device 7 is also provided on the rubber pipe 25 between the air pump 24 and the first and second air blowing pipes 22 . The constant flow device 7 is configured to allow the first air blowing pipe 21 and the second air blowing pipe 22 to discharge air evenly.

[0042] Preferably, the calibration tank 1, the first air blowing pipe 21, the second air blowing pipe 22, the constant flow device 7, the air pump 24 and the differential pressure transmitter 23 are buried deep underground.

[0043] The present invention also provides a control method for a flow calibration device of a metering pump in a radiation environment, wherein a liquid level sensor is provided in each of the first air blowing pipe and the second air blowing pipe, and a control center is provided on the differential pressure transmitter, wherein the liquid level sensor is used to detect the liquid level state in the first air blowing pipe and the second air blowing pipe, and the control center is used to calculate the pressure difference data and display the calculation result on the pressure difference transmitter, and the control method comprises the following steps: S1, sealing the emptying port of the device to prevent the metering pump medium from leaking from the emptying port;

[0044] S2, the metering pump inlet is opened and the metering pump medium is introduced, and at the same time the air pump ventilates the first and second air blowing pipes, and the air stabilizing valve is used to ensure the smooth air output, and the ventilation time is T1;

[0045] S3. After the T1 period, the differential pressure transmitter detects the liquid levels of the first air blowing pipe and the second air blowing pipe, and the detection results are H1 and H2 respectively;

[0046] S4, calculating the pressure difference between the first air blowing pipe and the second air blowing pipe through H1 and H2, and recording the current pressure difference;

[0047] S5, continue to introduce the metering pump medium, and ventilate the first air blowing pipe and the second air blowing pipe again, and the ventilation time is T2;

[0048] S6. After the T2 period, the liquid levels of the first air blowing pipe and the second air blowing pipe are detected again, and the detection results are H3 and H4 respectively;

[0049] S7, calculate the pressure difference between the first air blowing pipe and the second air blowing pipe again through H3 and H4, and record the pressure difference;

[0050] S8. Perform flow calibration calculation based on the twice measured pressure difference, and upload the calculation result to the control center, and perform flow calibration calculation through the control center.

[0051] Preferably, in steps S4 and S7, the pressure difference is calculated as:

[0052] (1)

[0053] in, is the pressure difference between the first blowing pipe and the second blowing pipe, is the density of the metering pump medium liquid, is the acceleration due to gravity, It is the measured liquid level in the current calibration tank.

[0054] Preferably, the step S5 also includes an overflow detection of the calibration tank, including the following steps: S51, the overflow outlet of the metering pump detects whether there is liquid passing through it. If so, it is determined that too much medium is currently passed into the metering pump, and the liquid level reaches the overflow outlet of the metering pump and overflows. The device stops ventilation and opens the emptying port to allow the metering pump medium to be discharged from the emptying port. Otherwise, it is determined that the liquid level in the calibration tank is normal and the device continues to operate.

[0055] Preferably, the control method further includes an emptying control of the calibration tank, comprising the following steps: S9, before the metering pump medium is introduced, opening the device emptying port, and simultaneously closing the metering pump medium inlet and the metering pump medium outlet;

[0056] S10, continue to ventilate the first air blowing tube and the second air blowing tube, and the ventilation time is T3;

[0057] S11, after the T3 time period, the ventilation is stopped, and the device detects whether there is liquid in the air blowing pipe. If so, it is determined that there is liquid in the calibration tank, and the device jumps back to S10 for re-detection. Otherwise, it is determined that there is no liquid in the current calibration tank, and jumps to S12 for further detection;

[0058] S12, the device opens the medium inlet and the medium outlet of the metering pump, and closes the device drain port for subsequent testing.

[0059] By providing an air blowing device on the top of the calibration tank body 1, the air blowing device includes a first air blowing pipe 21, a second air blowing pipe 22, a differential pressure transmitter 23 and an air pump 24, and a constant flow device 7 is provided between the air pump 24 and the first and second air blowing pipes 22. By adopting the above-mentioned setting scheme, air can be evenly blown into the first and second air blowing pipes 22 through the constant flow device 7. At the same time, since a metering pump medium for measurement is provided inside the calibration tank body 1, the metering pump medium exists in the portion of the air blowing pipe located at the bottom of the liquid surface. At the same time, when blowing, the air pressure in the air blowing pipe is greater than the static pressure of the liquid column at the lower end of the air blowing pipe. Pressure, gas bubbles out from the lower end of the air blowing pipe, and because the constant flow device 7 in the air blowing pipe limits the amount of supplementary gas in the pipe, the air blowing pipe pressure displayed on the differential pressure transmitter 23 is the static pressure of the liquid column. The static pressure value is used to calculate the pressure difference according to the pressure difference method through the static pressure and the liquid level height, and the result is uploaded to the control center. The measurement workpiece structure of the pressure difference and flow is compact, the span between each structure is small, the detection result is highly accurate, and the measurement structure is buried underground synchronously with the radioactive items, avoiding the harm of radioactive substances to the staff, and the safety is high.

[0060] Furthermore, in the process of adding the metering pump medium into the calibration tank body 1 and in the process of performing ventilation detection on the air blowing pipe, in order to avoid the overflow of the metering pump medium in the calibration tank body 1, the height of the metering pump inlet 3 on the side wall of the calibration tank body 1 is less than the height of the metering pump outlet on the side wall of the calibration tank body 1. When the metering pump medium is added into the calibration tank body 1 through the metering pump inlet 3, it is effectively prevented that the metering pump medium is added too much, thereby causing the metering pump to overflow from the top of the calibration tank body 1. At the same time, the bottom of the second air blowing pipe 22 is at the calibration tank body 1. The internal height is greater than the height of the metering pump outlet on the calibration tank body 1, which effectively prevents the metering pump medium from entering the second air blowing pipe 22, prevents the liquid from affecting the second air blowing pipe 22 and thus reducing the detection accuracy, and the present application can also simultaneously perform overflow detection on the calibration tank body 1 during the flow detection process. Specifically, when liquid passes through the overflow outlet of the calibration tank body 1, it means that there is too much metering pump medium in the calibration tank body 1. If the detection continues, it will lead to poor accuracy of the result, and the metering pump medium in the calibration tank body 1 needs to be discharged.

[0061] At the same time, during the detection process, in order to improve the accuracy of the detection, it is necessary to ensure the stability and uniformity of the ventilation process when the air blowing pipe is ventilated. A constant flow device 7 is provided between the pump body 6 and the air blowing pipe. The constant flow device 7 is used to limit the air flow passing therethrough to ensure uniform ventilation of the first and second air blowing pipes 22, and prevent the pressure value from changing, thereby causing a metering error. In the detection process, the pressure difference method is used to measure the flow rate. Specifically, the metering formula of the pressure difference method is: ∆P=γ×g×h, wherein ∆P is the pressure difference between the first air blowing pipe 21 and the second air blowing pipe 22 to be measured, γ is the density of the metering pump medium in the calibration tank body 1, g is the current gravitational acceleration, and h is the measured liquid level. In the process of ventilating the air blowing pipe, the liquid level of the air blowing pipe can be conveniently obtained, thereby calculating the pressure difference, and the detection is convenient. At the same time, by repeatedly introducing the metering pump medium and blowing the first and second air blowing pipes 22, the pressure difference is detected, the accuracy of the detection result is improved, and the detection effect is good.

[0062] In addition, before the flow detection, the calibration tank 1 needs to be emptied to prevent the presence of liquid in the calibration tank 1, thereby reducing the accuracy of the detection. The interior of the calibration tank 1 needs to be emptied and tested before the detection begins and after the detection is completed. Specifically, if there is residual liquid in the calibration tank 1, the actual volume of liquid involved in the calibration will be less than the theoretical calculation during the detection process. Therefore, it is necessary to keep the interior of the calibration tank 1 dry. After the calibration tank 1 is emptied, gas is continuously introduced into the calibration tank 1 to ensure that the interior of the calibration tank 1 is dry, thereby improving the accuracy of the detection.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A flow calibration device for a metering pump in a radiation environment, characterized in that: The invention comprises a calibration tank (1), wherein a blowing device is provided on the top of the calibration tank (1), wherein the blowing device comprises a first blowing pipe (21), a second blowing pipe (22), a differential pressure transmitter (23) and an air pump (24), wherein the first blowing pipe (21), the second blowing pipe (22), the differential pressure transmitter (23) and the air pump (24) are connected via a rubber pipe (25), wherein the first blowing pipe (21) extends to the bottom of the calibration tank (1) and leaves at least a gap with the bottom of the calibration tank (1) for liquid to pass through, wherein a metering pump inlet (3) and a metering pump overflow outlet (4) are provided on the side wall of the calibration tank (1), and an emptying port (5) is also provided at the bottom of the calibration tank (1), and the differential pressure transmitter (23) is used to calibrate the flow rate of the metering pump.

2. The flow calibration device for a metering pump in a radiation environment according to claim 1, characterized in that: The height of the metering pump inlet (3) on the side wall of the calibration tank (1) is less than the height of the metering pump outlet on the side wall of the calibration tank (1), and the height of the bottom of the second air blowing pipe (22) inside the calibration tank (1) is greater than the height of the metering pump outlet on the side wall of the calibration tank (1).

3. The flow calibration device for a metering pump in a radiation environment according to claim 1, characterized in that: The metering pump inlet (3), the metering pump overflow outlet (4) and the drain port (5) circulate in the device through a pipeline, and a pump body (6) is also provided at the lower end of the drain port (5).

4. The flow calibration device for a metering pump in a radiation environment according to claim 1, characterized in that: A constant flow device (7) is also provided on the rubber pipe (25) between the air pump (24) and the first and second air blowing pipes (22). The constant flow device (7) is configured to allow the first air blowing pipe (21) and the second air blowing pipe (22) to discharge air evenly.

5. The flow calibration device for a metering pump in a radiation environment according to claim 4, characterized in that: The calibration tank (1), the first air blowing pipe (21), the second air blowing pipe (22), the constant flow device (7), the air pump (24) and the differential pressure transmitter (23) are deeply buried underground.

6. A control method for a flow calibration device for a metering pump in a radiation environment applicable to any one of claims 1 to 5, characterized in that: The first air blowing pipe and the second air blowing pipe are both provided with a liquid level sensor, and the differential pressure transmitter is also provided with a control center, the liquid level sensor is used to detect the liquid level status in the first air blowing pipe and the second air blowing pipe, and the control center is used to calculate the pressure difference data and display the calculation result on the pressure difference transmitter, and the control method comprises the following steps: S1, sealing the emptying port of the device to prevent the medium of the metering pump from leaking from the emptying port; S2, the metering pump inlet is opened and the metering pump medium is introduced, and at the same time the air pump ventilates the first and second air blowing pipes, and the air stabilizing valve is used to ensure the smooth air output, and the ventilation time is T1; S3. After the T1 period, the differential pressure transmitter detects the liquid levels of the first air blowing pipe and the second air blowing pipe, and the detection results are H1 and H2 respectively; S4, calculating the pressure difference between the first air blowing pipe and the second air blowing pipe through H1 and H2, and recording the current pressure difference; S5, continue to introduce the metering pump medium, and ventilate the first air blowing pipe and the second air blowing pipe again, and the ventilation time is T2; S6. After the T2 period, the liquid levels of the first air blowing pipe and the second air blowing pipe are detected again, and the detection results are H3 and H4 respectively; S7, calculate the pressure difference between the first air blowing pipe and the second air blowing pipe again through H3 and H4, and record the pressure difference; S8. Perform flow calibration calculation based on the twice measured pressure difference, and upload the calculation result to the control center, and perform flow calibration calculation through the control center.

7. The control method of the flow calibration device of a metering pump in a radiation environment according to claim 6, characterized in that: In the steps S4 and S7, the pressure difference is calculated as: （1） in, is the pressure difference between the first blowing pipe and the second blowing pipe, is the density of the metering pump medium liquid, is the acceleration due to gravity, It is the measured liquid level in the current calibration tank.

8. The control method of the flow calibration device of a metering pump in a radiation environment according to claim 6, characterized in that: The step S5 also includes an overflow detection of the calibration tank, including the following steps: S51, the overflow outlet of the metering pump detects whether there is liquid passing through it. If so, it is determined that too much medium is currently passed into the metering pump, and the liquid level reaches the overflow outlet of the metering pump and overflows. The device stops ventilation and opens the drain port to allow the metering pump medium to be discharged from the drain port. Otherwise, it is determined that the liquid level in the calibration tank is normal and the device continues to operate.

9. The control method of the flow calibration device of a metering pump in a radiation environment according to claim 6, characterized in that: It also includes the emptying control of the calibration tank, including the following steps: S9, before the metering pump medium is introduced, the device emptying port is opened, and the metering pump medium inlet and the metering pump medium outlet are closed at the same time; S10, continue to ventilate the first air blowing tube and the second air blowing tube, and the ventilation time is T3; S11, after the T3 time period, the ventilation is stopped, and the device detects whether there is liquid in the air blowing pipe. If so, it is determined that there is liquid in the calibration tank, and the device jumps back to S10 for re-detection. Otherwise, it is determined that there is no liquid in the current calibration tank, and jumps to S12 for further detection; S12, the device opens the medium inlet and the medium outlet of the metering pump, and closes the device drain port for subsequent testing.

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