SF6 density relay comprehensive calibration instrument and calibration and measurement method

Abstract

The application discloses a kind of SF6 density relay comprehensive calibration instrument and calibration and measurement method, including intermediate pipeline and be located on the air pump of intermediate pipeline, the one end of the intermediate pipeline is respectively communicated with the one end of safety valve pipeline, first pipeline one end, second pipeline one end, the other end of intermediate pipeline is respectively communicated with the one end of micro water measuring pipeline and third pipeline one end, the other end of the micro water measuring pipeline is respectively communicated with the one end of inlet pipeline and purity measuring pipeline, the other end of third pipeline is respectively communicated with the other end of first pipeline and fourth pipeline one end, the other end of the fourth pipeline is respectively communicated with the other end of purity measuring pipeline, the other end of second pipeline and muffler pipeline, intermediate pipeline side is equipped with suction pipeline;The application has adopted new pneumatic circuit design, combines density relay system calibration circuit with moisture measurement circuit and purity measurement circuit together, with the characteristics such as high measurement efficiency, convenient, its loop structure is simplified, and measurement is efficient.

Description

Technical Field

[0001] This invention relates to the field of SF6 density relay technology, specifically to an SF6 density relay comprehensive calibration instrument and calibration and measurement method. Background Technology

[0002] Currently, the calibration of SF6 density relays is mainly conducted using two media: SF6 gas and air, and both methods are widely used. The characteristics of these two media are as follows: using SF6 gas as the calibration medium has advantages such as no conversion required for measurement and consistency with on-site operating conditions. However, using SF6 gas requires carrying SF6 cylinders, which is neither safe nor environmentally friendly, and also not portable, with the overall weight typically reaching 30-40 kg. Furthermore, when using air as the calibration medium, the measured values ​​need to be converted to 20°C, requiring conversions in pressure and temperature. Additionally, after each measurement, air in the SF6 valve block and gauge may be forced into the GIS or GIL gas chamber, and repeated measurements can easily cause a gradual increase in moisture in the gas chamber. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned shortcomings and provide an SF6 density relay comprehensive calibration instrument and calibration and measurement method to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: an SF6 density relay comprehensive calibration instrument, comprising an intermediate pipeline and an air pump disposed on the intermediate pipeline. One end of the intermediate pipeline is connected to one end of a safety valve pipeline, one end of a first pipeline, and one end of a second pipeline, respectively. The other end of the intermediate pipeline is connected to one end of a micro-moisture measurement pipeline and one end of a third pipeline, respectively. The other end of the micro-moisture measurement pipeline is connected to one end of an air inlet pipeline and one end of a purity measurement pipeline, respectively. The other end of the third pipeline is connected to one end of the first pipeline and one end of a fourth pipeline, respectively. The other end of the fourth pipeline is connected to one end of the purity measurement pipeline, one end of the second pipeline, and a silencer pipeline, respectively. An air extraction pipeline is provided on the side of the intermediate pipeline.

[0005] Preferably, the first pipeline is provided with a first solenoid valve and a second check valve, the second pipeline is provided with a second solenoid valve, the air extraction pipeline is provided with a third solenoid valve, the intermediate pipeline is provided with a first check valve, an air pump, a vacuum sensor and a fourth solenoid valve, the micro-water measurement pipeline is provided with a fifth solenoid valve, the fourth pipeline is provided with a sixth solenoid valve, and the purity measurement pipeline is provided with a seventh solenoid valve.

[0006] Preferably, the extraction pipe is equipped with a first filter, and the intake pipe is equipped with a second filter and an instrument quick connector.

[0007] Preferably, a micro-water density sensor is provided on the micro-water measurement pipeline, and a purity measurement sensor is provided on the purity measurement pipeline.

[0008] Preferably, the silencer pipeline is provided with a first silencer and a third check valve, and the safety valve pipeline is provided with a safety valve and a second silencer.

[0009] This invention discloses a calibration method for the aforementioned SF6 density relay integrated calibration instrument, which includes the following steps:

[0010] S1: Pressurization steps: Power on and open the first, third, and fifth solenoid valves, and de-energize and close the remaining solenoid valves. Start the air pump. The gas enters the intermediate pipeline from the first filter of the suction pipeline. After passing through the air pump, the gas is gradually pressurized and then passes through the first pipeline, the third pipeline, the micro-water measurement pipeline, and the air inlet pipeline in sequence. Finally, it enters the density relay system through the instrument quick connector, thereby testing the density relay system.

[0011] S2: Exhaust procedure: After the density relay system pressure is maintained for 5-10 seconds, close the air pump, the first solenoid valve and the third solenoid valve, and slowly exhaust the gas. At this time, open the sixth solenoid valve. The gas in the density relay system passes through the air intake pipe, the micro water measurement pipe, the third pipe and the fourth pipe, and is finally discharged from the first silencer until the pressure is zero after all the gas is discharged.

[0012] S3: Vacuuming procedure: Open the fifth, fourth, and second solenoid valves, and close all other solenoid valves. Start the air pump. In the density relay system, the gas passes through the instrument quick connector, the micro-water measurement pipeline, and the first one-way valve. Then, it is drawn out by the air pump to the second pipeline and finally discharged from the first silencer. The density relay system gradually enters a negative pressure state. When the vacuum sensor detects that the vacuum level has reached the set value, it sends a feedback signal to control the air pump to stop running. Then, the power is cut off and all solenoid valves are closed.

[0013] Preferably, in step S1, the micro-water density sensor detects the pressure in the gas in the detection circuit. When the pressure is measured to be 1 MPa, an electrical feedback signal is sent to control the gas pump to stop running and to de-energize and close the first and third solenoid valves. At this time, the pressure of the density relay system is maintained at the set 1 MPa.

[0014] If, for some reason, the micro-water density sensor or the air pump malfunctions and the air pump continues to pressurize, when the pressure exceeds 1 MPa, the safety valve on the safety valve pipeline will open, allowing gas to be exhausted through the second silencer of the safety valve, reducing the pressure of the density relay system, thereby protecting the density relay system and preventing damage caused by overpressure.

[0015] This invention discloses a moisture measurement method for the aforementioned SF6 density relay integrated calibration instrument, which includes the following steps:

[0016] Step 1: Pressurization Step: Power on and open the first, third, and fifth solenoid valves, and de-energize and close the remaining solenoid valves. Start the air pump, and the gas enters the intermediate pipeline from the first filter of the air extraction pipeline. After passing through the air pump, the gas is gradually pressurized and then passes through the first pipeline, the third pipeline, the micro-water measurement pipeline, and the air inlet pipeline in sequence. Finally, the gas enters the density relay system through the instrument quick connector, thereby testing the density relay system.

[0017] Step 2: Exhaust procedure: After maintaining the pressure of the density relay system for 5-10 seconds, close the air pump, the first solenoid valve and the third solenoid valve, and slowly exhaust the gas. At this time, open the sixth solenoid valve. The gas in the density relay system passes through the air inlet pipe, the micro water measurement pipe, the third pipe and the fourth pipe, and is finally discharged from the first silencer until the pressure is zero after all the gas is discharged.

[0018] Step 3: Vacuuming process: Open the fifth, fourth, and second solenoid valves, and close all other solenoid valves. Start the air pump. In the density relay system, the gas passes through the instrument quick connector, the micro-water measurement pipeline, and the first one-way valve. Then, it is drawn out by the air pump to the second pipeline and finally discharged from the first silencer. The density relay system gradually enters a negative pressure state. When the vacuum sensor detects that the vacuum level has reached the set value, it sends a feedback signal to control the air pump to stop running. Then, the power is cut off and all solenoid valves are closed.

[0019] Step 4: Moisture Measurement Procedure: After the instrument completes the vacuuming process, power off and close all solenoid valves. Then connect the instrument quick connector to the GIS calibration valve assembly connector, open the valves on the GIS body, close the seventh solenoid valve, and open the fifth solenoid valve. The gas inside the GIS body enters the micro-moisture measurement pipeline due to the negative pressure. The micro-moisture density sensor starts the moisture measurement function. After measuring for 1 minute, record the current moisture value to complete the moisture measurement.

[0020] This invention discloses a method for measuring the purity of SF6 gas using the aforementioned SF6 density relay integrated calibration instrument, characterized by comprising the following steps:

[0021] Step 1: Pressurization Step: Power on and open the first, third, and fifth solenoid valves, and de-energize and close the remaining solenoid valves. Start the air pump. The gas enters the intermediate pipeline from the first filter of the suction pipeline. After passing through the air pump, the gas is gradually pressurized and then passes through the first pipeline, the third pipeline, the micro-water measurement pipeline, and the air inlet pipeline in sequence. Finally, it enters the density relay system through the instrument quick connector, thereby testing the density relay system.

[0022] Step 2: Exhaust procedure: After maintaining the pressure of the density relay system for 5-10 seconds, close the air pump, the first solenoid valve and the third solenoid valve to slowly exhaust the gas. At this time, open the sixth solenoid valve. The gas in the density relay system passes through the air inlet pipe, the micro water measurement pipe, the third pipe and the fourth pipe, and is finally discharged from the first silencer until the pressure is zero after all the gas is discharged.

[0023] Step 3: Vacuuming Step: Open the fifth, fourth, and second solenoid valves, and close all other solenoid valves. Start the air pump. In the density relay system, the gas passes through the instrument quick connector, the micro-water measurement pipeline, and the first one-way valve. Then, it is drawn out by the air pump to the second pipeline and finally discharged from the first silencer. The density relay system gradually enters a negative pressure state. When the vacuum sensor detects that the vacuum level has reached the set value, it sends a feedback signal to control the air pump to stop running. Then, the power is cut off and all solenoid valves are closed.

[0024] Step 4: SF6 Gas Purity Measurement Procedure: After the instrument completes the vacuuming process, power off and close all solenoid valves. Then, connect the instrument quick connector to the GIS calibration valve assembly connector, open the valves on the GIS body, the seventh solenoid valve opens, and the fifth solenoid valve closes. The gas inside the GIS body enters the purity measurement pipeline due to the negative pressure. The purity measurement sensor starts the purity measurement function. After measuring for 1 minute, record the purity data to complete the purity measurement.

[0025] The beneficial effects of this invention are:

[0026] 1. This invention solves the problems of inconvenience and safety associated with traditional density relay calibration, such as the need to carry SF6 gas cylinders and convert the measured values ​​to 20°C, through a new pneumatic circuit design. At the same time, it also combines moisture measurement and purity measurement functions, making it more practical.

[0027] 2. This invention adopts a new pneumatic circuit design, which combines the density relay system calibration circuit with the moisture measurement circuit and the purity measurement circuit. It has the characteristics of high measurement efficiency and convenience. Its circuit structure is simplified and the measurement is highly efficient.

[0028] 3. The present invention adopts an integrated structure of valve block and a small number of pipelines, and the gas flows in the flow channel inside the valve block, avoiding the problems of many joints and many leakage points.

[0029] 4. During measurement, the present invention utilizes the negative pressure of the calibration circuit, the moisture measurement circuit, and the purity measurement circuit to draw gas into the corresponding measurement circuit for measurement. In this way, during and after the measurement process, the air in the corresponding valve block and meter will not be forced into the GIS or GIL gas chamber. Even after multiple measurements, it is not easy for the moisture in the gas chamber to gradually increase.

[0030] 5. This invention can use a miniature solenoid valve, a small air pump, and a built-in one-way valve structure, which effectively reduces the size and makes it easy to carry. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of an SF6 density relay integrated calibration instrument. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, an SF6 density relay comprehensive calibration instrument includes an intermediate pipeline 1 and an air pump 1.2 installed on the intermediate pipeline 1. One end of the intermediate pipeline 1 is connected to one end of the safety valve pipeline 3, one end of the first pipeline 4, and one end of the second pipeline 5, respectively. The other end of the intermediate pipeline 1 is connected to one end of the micro-moisture measuring pipeline 6 and one end of the third pipeline 7, respectively. The other end of the micro-moisture measuring pipeline 6 is connected to one end of the air inlet pipeline 8 and one end of the purity measuring pipeline 9, respectively. The other end of the third pipeline 7 is connected to the other end of the first pipeline 4 and one end of the fourth pipeline 10, respectively. The other end of the fourth pipeline 10 is connected to the other end of the purity measuring pipeline 9, the other end of the second pipeline 5, and the silencer pipeline 11, respectively. An air extraction pipeline 2 is provided on the side of the intermediate pipeline 1.

[0034] Preferably, the first pipeline 4 is provided with a first solenoid valve 4.1 and a second check valve 4.2, the second pipeline 5 is provided with a second solenoid valve 5.1, the air extraction pipeline 2 is provided with a third solenoid valve 2.1, the intermediate pipeline 1 is provided with a first check valve 1.1, an air pump 1.2, a vacuum sensor 1.3 and a fourth solenoid valve 1.4, the micro-water measurement pipeline 6 is provided with a fifth solenoid valve 6.1, the fourth pipeline 10 is provided with a sixth solenoid valve 10.1, and the purity measurement pipeline 9 is provided with a seventh solenoid valve 9.1.

[0035] Preferably, the air extraction pipe 2 is provided with a first filter 2.2, and the air intake pipe 8 is provided with a second filter 8.1 and an instrument quick connector 8.2.

[0036] Preferably, a micro-water density sensor 6.2 is provided on the micro-water measurement pipeline 6, and a purity measurement sensor 9.2 is provided on the purity measurement pipeline 9.

[0037] Preferably, the silencer pipeline 11 is provided with a first silencer 11.1 and a third one-way valve 11.2, and the safety valve pipeline 3 is provided with a safety valve 3.1 and a second silencer 3.2.

[0038] In the above technical solution, the specific roles of each institution are as follows:

[0039] Air pump: The power source for pressurizing or evacuating the density relay system.

[0040] Solenoid valve: It has two states, on and off, connecting or disconnecting the corresponding circuit.

[0041] One-way valve: allows gas to flow in only one direction (see details below). Figure 1 (Indicated by the direction shown) to prevent gas backflow.

[0042] Micro-water density sensor: Detects the pressure and water content in the gas in the detection loop, outputs a corresponding electrical signal (pressure), and transmits it to the controller to control the start and stop of the air pump. The specific model is GDHT-20 sensor.

[0043] Purity measurement sensor: detects the SF6 gas content in the gas, specifically the TGBS-1000 sensor.

[0044] Vacuum sensor: detects the vacuum level in the circuit, outputs the corresponding electrical signal, and transmits it to the controller to stop the air pump.

[0045] Filter: Filters impurities in the gas entering the gas path, ensuring the normal operation of components and extending their lifespan.

[0046] Muffler: Reduces noise during exhaust. Significantly reduces the harsh noise generated when releasing high-pressure gases.

[0047] Safety valve: A pressure value is set. When the pressure in the air circuit exceeds the set value, the safety valve opens to release gas, ensuring that the pressure in the density relay system does not exceed the limit value, thus protecting the density relay system.

[0048] Example 1: This invention discloses a calibration method for the above-mentioned SF6 density relay integrated calibration instrument, which includes the following steps:

[0049] S1: Pressurization steps: Power on and open the first solenoid valve 4.1, the third solenoid valve 2.1, and the fifth solenoid valve 6.1. De-energize and close the remaining solenoid valves. Start the air pump 1.2. The gas enters the intermediate pipeline 1 from the first filter 2.2 of the suction pipeline 2. After passing through the air pump 1.2, the gas is gradually pressurized. Then, it passes through the first pipeline 4, the third pipeline 7, the micro-water measurement pipeline 6, and the air inlet pipeline 8 in sequence. Finally, it enters the density relay system through the instrument quick connector 8.2, thereby testing the density relay system.

[0050] S2: Exhaust procedure: After the density relay system pressure is maintained for 5-10 seconds, close the air pump 1.2, the first solenoid valve 4.1 and the third solenoid valve 2.1 to slowly exhaust the gas. At this time, open the sixth solenoid valve 10.1. The gas in the density relay system passes through the air inlet pipe 8, the micro water measurement pipe 6, the third pipe 7 and the fourth pipe 10, and is finally discharged from the first silencer 11.1 until the pressure is zero after all the gas is discharged.

[0051] S3: Vacuuming procedure: Open the fifth solenoid valve 6.1, the fourth solenoid valve 1.4, and the second solenoid valve 5.1, and close all other solenoid valves. Start the air pump 1.2. In the density relay system, the gas passes through the instrument quick connector 8.2, the micro-water measurement pipeline 6, and the first one-way valve 1.1, and is then drawn out by the air pump 1.2 to the second pipeline 5, and finally discharged from the first silencer 11.1. The density relay system gradually enters a negative pressure state. When the vacuum sensor 1.3 detects that the vacuum degree has reached the set value, it sends a feedback signal to control the air pump 1.2 to stop running, and then cuts off the power to close all solenoid valves.

[0052] Preferably, in step S1, the micro-water density sensor 6.2 detects the pressure in the gas in the detection circuit. When the pressure is measured to be 1 MPa, an electrical feedback signal is sent to control the gas pump 1.2 to stop running and to de-energize and close the first solenoid valve 4.1 and the third solenoid valve 2.1. At this time, the pressure of the density relay system is maintained at the set 1 MPa.

[0053] If, for some reason, the micro-water density sensor 6.2 or the air pump 1.2 malfunctions, and the air pump 1.2 continues to pressurize, when the pressure exceeds 1 MPa, the safety valve 3.1 on the safety valve pipeline 3 opens, allowing gas to be exhausted through the second silencer 3.2 of the safety valve 3.1, reducing the pressure of the density relay system, thereby protecting the density relay system and preventing damage caused by overpressure.

[0054] Example 2: This invention discloses a moisture measurement method for the above-mentioned SF6 density relay integrated calibration instrument, which includes the following steps:

[0055] Step 1: Pressurization Step: Power on and open the first solenoid valve 4.1, the third solenoid valve 2.1, and the fifth solenoid valve 6.1. De-energize and close the remaining solenoid valves. Start the air pump 1.2. The gas enters the intermediate pipeline 1 from the first filter 2.2 of the suction pipeline 2. After passing through the air pump 1.2, the gas is gradually pressurized and then passes through the first pipeline 4, the third pipeline 7, the micro-water measurement pipeline 6, and the air inlet pipeline 8 in sequence. Finally, the gas enters the density relay system through the instrument quick connector 8.2, thereby testing the density relay system.

[0056] Step 2: Exhaust procedure: After maintaining the pressure of the density relay system for 5-10 seconds, close the air pump 1.2, the first solenoid valve 4.1 and the third solenoid valve 2.1 to slowly exhaust the gas. At this time, open the sixth solenoid valve 10.1. The gas in the density relay system passes through the air inlet pipe 8, the micro water measurement pipe 6, the third pipe 7 and the fourth pipe 10, and is finally discharged from the first silencer 11.1 until the pressure is zero after all the gas is discharged.

[0057] Step 3: Vacuuming process: Open the fifth solenoid valve 6.1, the fourth solenoid valve 1.4, and the second solenoid valve 5.1, and close all other solenoid valves. Start the air pump 1.2. The gas in the density relay system passes through the instrument quick connector 8.2, the micro-water measurement pipeline 6, and the first one-way valve 1.1, and is then drawn out by the air pump 1.2 to the second pipeline 5, and finally discharged from the first silencer 11.1. The density relay system gradually enters a negative pressure state. When the vacuum sensor 1.3 detects that the vacuum degree has reached the set value, it sends a feedback signal to control the air pump 1.2 to stop running, and then cuts off the power to close all solenoid valves.

[0058] Step 4: Moisture Measurement Procedure: After the instrument calibration completes the vacuuming process, power off and close all solenoid valves. Then, connect the instrument quick connector 8.2 to the GIS calibration valve assembly connector, open the valves on the GIS body, close the seventh solenoid valve 9.1, and open the fifth solenoid valve 6.1. The gas inside the GIS body enters the micro-moisture measurement pipeline 6 due to the negative pressure. The micro-moisture density sensor 6.2 starts the moisture measurement function. After measuring for 1 minute, record the current moisture value to complete the moisture measurement.

[0059] Example 3: This invention discloses a method for measuring the purity of SF6 gas using the aforementioned SF6 density relay integrated calibration instrument, characterized by the following steps:

[0060] Step 1: Pressurization Step: Power on and open the first solenoid valve 4.1, the third solenoid valve 2.1, and the fifth solenoid valve 6.1. De-energize and close the remaining solenoid valves. Start the air pump 1.2. The gas enters the intermediate pipeline 1 from the first filter 2.2 of the suction pipeline 2. After passing through the air pump 1.2, the gas is gradually pressurized and then passes through the first pipeline 4, the third pipeline 7, the micro-water measurement pipeline 6, and the air inlet pipeline 8 in sequence. Finally, the gas enters the density relay system through the instrument quick connector 8.2, thereby testing the density relay system.

[0061] Step 2: Exhaust procedure: After maintaining the pressure of the density relay system for 5-10 seconds, close the air pump 1.2, the first solenoid valve 4.1 and the third solenoid valve 2.1 to slowly exhaust the gas. At this time, open the sixth solenoid valve 10.1. The gas in the density relay system passes through the air inlet pipe 8, the micro-water measurement pipe 6, the third pipe 7 and the fourth pipe 10, and is finally discharged from the first silencer 11.1 until the pressure is zero after all the gas is discharged.

[0062] Step 3: Vacuuming Step: Open the fifth solenoid valve 6.1, the fourth solenoid valve 1.4, and the second solenoid valve 5.1, and close all other solenoid valves. Start the air pump 1.2. The gas in the density relay system passes through the instrument quick connector 8.2, the micro-water measurement pipeline 6, and the first one-way valve 1.1, and is then drawn out by the air pump 1.2 to the second pipeline 5, and finally discharged from the first silencer 11.1. The density relay system gradually enters a negative pressure state. When the vacuum sensor 1.3 detects that the vacuum degree has reached the set value, it sends a feedback signal to control the air pump 1.2 to stop running, and then cuts off the power to close all solenoid valves.

[0063] Step 4: SF6 Gas Purity Measurement Procedure: After the instrument completes the vacuuming process, power off and close all solenoid valves. Then, connect the instrument quick connector 8.2 to the GIS calibration valve assembly connector, open the valves on the GIS body, open the seventh solenoid valve 9.1, and close the fifth solenoid valve 6.1. The gas inside the GIS body enters the purity measurement pipeline 9 due to the negative pressure. The purity measurement sensor 9.2 starts the purity measurement function. After measuring for 1 minute, record the purity data to complete the purity measurement.

[0064] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The embodiments and features described in these embodiments can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. An SF6 density relay integrated calibration instrument, comprising an intermediate pipeline (1) and an air pump (1.2) disposed on the intermediate pipeline (1), characterized in that: One end of the intermediate pipeline (1) is connected to one end of the safety valve pipeline (3), one end of the first pipeline (4), and one end of the second pipeline (5). The other end of the intermediate pipeline (1) is connected to one end of the micro-water measurement pipeline (6) and one end of the third pipeline (7). The other end of the micro-water measurement pipeline (6) is connected to one end of the air inlet pipeline (8) and one end of the purity measurement pipeline (9). The other end of the third pipeline (7) is connected to the other end of the first pipeline (4) and one end of the fourth pipeline (10). The other end of the fourth pipeline (10) is connected to the other end of the purity measurement pipeline (9), the other end of the second pipeline (5), and the silencer pipeline (11). An air extraction pipeline (2) is provided on the side of the intermediate pipeline (1).

2. The SF6 density relay comprehensive calibration instrument according to claim 1, characterized in that: The first pipeline (4) is equipped with a first solenoid valve (4.1) and a second check valve (4.2), the second pipeline (5) is equipped with a second solenoid valve (5.1), the air extraction pipeline (2) is equipped with a third solenoid valve (2.1), the intermediate pipeline (1) is equipped with a first check valve (1.1), an air pump (1.2), a vacuum sensor (1.3) and a fourth solenoid valve (1.4), the micro-water measurement pipeline (6) is equipped with a fifth solenoid valve (6.1), the fourth pipeline (10) is equipped with a sixth solenoid valve (10.1), and the purity measurement pipeline (9) is equipped with a seventh solenoid valve (9.1).

3. The SF6 density relay comprehensive calibration instrument according to claim 2, characterized in that: The extraction pipe (2) is equipped with a first filter (2.2), and the intake pipe (8) is equipped with a second filter (2.2). 8.1) and instrument quick connectors (8.2).

4. The SF6 density relay comprehensive calibration instrument according to claim 3, characterized in that: The micro water density sensor (6.2) is installed on the micro water measurement pipeline (6), and the purity measurement sensor (9.2) is installed on the purity measurement pipeline (9).

5. The SF6 density relay comprehensive calibration instrument according to claim 4, characterized in that: The silencer pipeline (11) is equipped with a first silencer (11.1) and a third check valve (11.2), and the safety valve pipeline (3) is equipped with a safety valve (3.1) and a second silencer (3.2).

6. A calibration method for the SF6 density relay integrated calibration instrument as described in claim 5, characterized in that: It includes the following steps: S1: Pressurization steps: Power on and open the first solenoid valve (4.1), the third solenoid valve (2.1) and the fifth solenoid valve (6.1), and de-energize and close the remaining solenoid valves. Start the air pump (1.2). The gas enters the intermediate pipeline (1) from the first filter (2.2) of the air extraction pipeline (2). After passing through the air pump (1.2), the gas is gradually pressurized and then passes through the first pipeline (4), the third pipeline (7), the micro-water measurement pipeline (6) and the air inlet pipeline (8) in sequence. Finally, it enters the density relay system through the instrument quick connector (8.2) to test the density relay system. S2: Exhaust procedure: After the density relay system pressure is maintained for 5-10 seconds, the air pump (1.2), the first solenoid valve (4.1) and the third solenoid valve (2.1) are closed to slowly exhaust the gas. At this time, the sixth solenoid valve (10.1) is opened. The gas in the density relay system passes through the air inlet pipe (8), the micro water measurement pipe (6), the third pipe (7) and the fourth pipe (10), and is finally discharged from the first silencer (11.1) until the pressure is zero after all the gas is discharged. S3: Vacuuming steps: Open the fifth solenoid valve (6.1), the fourth solenoid valve (1.4), and the second solenoid valve (5.1), and close all other solenoid valves. Start the air pump (1.2). The gas in the density relay system passes through the instrument quick connector (8.2), the micro-water measurement pipeline (6), and the first one-way valve (1.1), and is then drawn out by the air pump (1.2) to the second pipeline (5), and finally discharged from the first silencer (11.1). The density relay system gradually enters a negative pressure state. When the vacuum sensor (1.3) detects that the vacuum degree has reached the set value, it sends a feedback signal to control the air pump (1.2) to stop running, and then cuts off the power to close all solenoid valves.

7. The calibration method of the SF6 density relay comprehensive calibration instrument according to claim 6, characterized in that: In step S1, the micro water density sensor (6.2) detects the pressure in the gas in the detection circuit. When the pressure is measured to be 1 MPa, an electrical feedback signal is sent to control the gas pump (1.2) to stop running and to de-energize and close the first solenoid valve (4.1) and the third solenoid valve (2.1). At this time, the pressure of the density relay system is maintained at the set 1 MPa. If, for some reason, the micro-water density sensor (6.2) or the air pump (1.2) malfunctions, and the air pump (1.2) continues to pressurize, when the pressure exceeds 1 MPa, the safety valve (3.1) on the safety valve pipeline (3) opens, thereby allowing the gas to be exhausted through the second silencer (3.2) of the safety valve (3.1), reducing the pressure of the density relay system, thereby protecting the density relay system and preventing damage caused by overpressure.

8. A method for measuring moisture content in an SF6 density relay integrated calibration instrument as described in claim 5, characterized in that: It includes the following steps: Step 1: Pressurization step: Power on and open the first solenoid valve (4.1), the third solenoid valve (2.1) and the fifth solenoid valve (6.1), and de-energize and close the remaining solenoid valves. Start the air pump (1.2). The gas enters the intermediate pipeline (1) from the first filter (2.2) of the air extraction pipeline (2). After passing through the air pump (1.2), the gas is gradually pressurized and then passes through the first pipeline (4), the third pipeline (7), the micro water measurement pipeline (6) and the air inlet pipeline (8) in sequence. Finally, it enters the density relay system through the instrument quick connector (8.2) to test the density relay system. Step 2: Exhaust procedure: After the density relay system pressure is maintained for 5-10 seconds, close the air pump (1.2), the first solenoid valve (4.1) and the third solenoid valve (2.1) to slowly exhaust the gas. At this time, open the sixth solenoid valve (10.1). The gas in the density relay system passes through the air inlet pipe (8), the micro water measurement pipe (6), the third pipe (7) and the fourth pipe (10), and is finally discharged from the first silencer (11.1) until the pressure is zero after all the gas is discharged. Step 3: Vacuuming Step: Open the fifth solenoid valve (6.1), the fourth solenoid valve (1.4), and the second solenoid valve (5.1), and close all other solenoid valves. Start the air pump (1.2). The gas in the density relay system passes through the instrument quick connector (8.2), the micro-water measurement pipeline (6), and the first one-way valve (1.1), and is then drawn out by the air pump (1.2) to the second pipeline (5), and finally discharged from the first silencer (11.1). The density relay system gradually enters a negative pressure state. When the vacuum sensor (1.3) detects that the vacuum degree has reached the set value, it sends a feedback signal to control the air pump (1.2) to stop running, and then cuts off the power to close all solenoid valves. Step 4: Moisture Measurement Steps: After the instrument completes the vacuuming step, power off and close all solenoid valves. Then connect the instrument quick connector (8.2) to the GIS calibration valve assembly connector, open the valve on the GIS body, close the seventh solenoid valve (9.1), and open the fifth solenoid valve (6.1). The gas inside the GIS body enters the micro-moisture measurement pipeline (6) due to the negative pressure. The micro-moisture density sensor (6.2) starts the moisture measurement function. After measuring for 1 minute, record the current moisture value to complete the moisture measurement.

9. A method for measuring the purity of SF6 gas using the SF6 density relay integrated calibration instrument as described in claim 5, characterized in that: It includes the following steps: Step 1: Pressurization Step: Power on and open the first solenoid valve (4.1), the third solenoid valve (2.1), and the fifth solenoid valve (6.1). Power off and close the remaining solenoid valves. Start the air pump (1.2). The gas enters the intermediate pipeline (1) from the first filter (2.2) of the suction pipeline (2). After passing through the air pump (1.2), the gas is gradually pressurized. Then, it passes through the first pipeline (4), the third pipeline (7), the micro-water measurement pipeline (6), and the air inlet pipeline (8) in sequence. Finally, it enters the density relay system through the instrument quick connector (8.2) to test the density relay system. Step 2: Exhaust procedure: After maintaining the pressure of the density relay system for 5-10 seconds, close the air pump (1.2), the first solenoid valve (4.1) and the third solenoid valve (2.1) to slowly exhaust the gas. At this time, open the sixth solenoid valve (10.1). The gas in the density relay system passes through the air inlet pipe (8), the micro water measurement pipe (6), the third pipe (7) and the fourth pipe (10), and is finally discharged from the first silencer (11.1) until the pressure is zero after all the gas is discharged. Step 3: Vacuuming Step: Open the fifth solenoid valve (6.1), the fourth solenoid valve (1.4), and the second solenoid valve (5.1), and close all other solenoid valves. Start the air pump (1.2). The gas in the density relay system passes through the instrument quick connector (8.2), the micro-water measurement pipeline (6), and the first one-way valve (1.1), and is then drawn out by the air pump (1.2) to the second pipeline (5), and finally discharged from the first silencer (11.1). The density relay system gradually enters a negative pressure state. When the vacuum sensor (1.3) detects that the vacuum degree has reached the set value, it sends a feedback signal to control the air pump (1.2) to stop running, and then cuts off the power to close all solenoid valves. Step 4: SF6 gas purity measurement steps: After the instrument completes the vacuuming step, power off and close all solenoid valves. Then connect the instrument quick connector (8.2) to the GIS calibration valve group connector, open the valve on the GIS body, the seventh solenoid valve (9.1) opens, and the fifth solenoid valve (6.1) closes. The gas in the GIS body enters the purity measurement pipeline (9) due to the negative pressure. The purity measurement sensor (9.2) starts the purity measurement function. After measuring for 1 minute, record the purity data to complete the purity measurement.

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