A device and method for checking the error of tungsten-rhenium thermocouple indication during the test

Abstract

The present invention discloses a device and method for checking the indication error of a tungsten-rhenium thermocouple. The device includes a heating mechanism, a tungsten-rhenium thermocouple checking mechanism arranged in the heating mechanism, and a thermocouple fixing frame arranged on one side of the heating mechanism and cooperating with the tungsten-rhenium thermocouple checking mechanism. The method includes: 1. constructing an argon environment; 2. placing a solid standard sample and installing a thermocouple; 3. making a standard temperature source; 4. checking the indication error of the tungsten-rhenium thermocouple to be checked. The present invention uses an air inlet pipe and an air outlet pipe to construct an argon environment inside the tungsten-rhenium thermocouple checking mechanism to avoid oxidation during the checking process of the tungsten-rhenium thermocouple to be checked, and then puts the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be checked into a crucible at the same time, and uses a standard metal sample to check the indication error of the tungsten-rhenium thermocouple to be checked. It is not limited by the traditional thermocouple checking region and laboratory, and does not require regular traceability.

Description

Technical Field

[0001] This invention belongs to the field of tungsten-rhenium thermocouple periodic verification technology, and in particular relates to a device and method for periodic verification of tungsten-rhenium thermocouple indication error. Background Technology

[0002] Currently, the verification of the indication error of tungsten-rhenium thermocouples can be carried out according to the JJF1176-2007 (0~1500)℃ tungsten-rhenium thermocouple calibration specification. This requires heating the thermocouple calibration furnace to the calibration temperature point and then verifying the indication error after the temperature stabilizes. Thermocouple verification takes 6-8 hours, which is inefficient. Moreover, traditional thermocouple calibration is limited by region and laboratory, and cannot meet the needs of online and on-site verification of thermocouple indication errors. Furthermore, the existing verification methods are limited to tungsten-rhenium thermocouple calibration at (0~1500)℃, and there is no method for verifying tungsten-rhenium thermocouples above 1500℃. Summary of the Invention

[0003] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a device for verifying the indication error of tungsten-rhenium thermocouples. This device utilizes an inlet and outlet pipe to create an argon atmosphere inside the tungsten-rhenium thermocouple verification mechanism, preventing oxidation during the verification process. The temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be verified are simultaneously placed in a crucible. A heating furnace provides a heat source to the crucible, melting the solid metal inside and using it as the temperature source for both the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be verified. A standard metal sample is used to verify the indication error of the tungsten-rhenium thermocouple to be verified. This method is not limited by the geographical location or laboratory of traditional thermocouple verification and does not require periodic traceability.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a tungsten-rhenium thermocouple indication error verification device, characterized in that: it includes a heating mechanism, a tungsten-rhenium thermocouple verification mechanism disposed in the heating mechanism, and a thermocouple fixing frame disposed on one side of the heating mechanism and cooperating with the tungsten-rhenium thermocouple verification mechanism;

[0005] The heating mechanism includes a heating furnace and a crucible vertically arranged on the heating furnace, and the top of the heating furnace is provided with a sealing cover;

[0006] The bottom of the tungsten-rhenium thermocouple verification mechanism is in close contact with the bottom of the crucible, and the top of the tungsten-rhenium thermocouple verification mechanism extends through the sealing cover to above the sealing cover. Multiple thermocouple sheaths to be verified and one temperature-controlled thermocouple sheath are vertically arranged inside the tungsten-rhenium thermocouple verification mechanism. The bottoms of both the thermocouple sheaths to be verified and the temperature-controlled thermocouple sheath are flush with the bottom of the sealing cover, and the tops of both extend through the top of the tungsten-rhenium thermocouple verification mechanism to above the tungsten-rhenium thermocouple verification mechanism. The bottoms of both the thermocouple sheaths to be verified and the temperature-controlled thermocouple sheath are connected to the interior of the tungsten-rhenium thermocouple verification mechanism.

[0007] The upper part of the tungsten-rhenium thermocouple verification mechanism is symmetrically provided with an inlet pipe and an outlet pipe. An argon cylinder is connected to the inlet pipe, and a gas sensor is installed at the outlet pipe opening. Both the inlet pipe and the outlet pipe are connected to the interior of the tungsten-rhenium thermocouple verification mechanism.

[0008] The thermocouple holder includes a holder body disposed on one side of the crucible, an adjustable mounting base disposed on the holder body and movable along the height direction of the holder body, and a clamp disposed on the adjustable mounting base.

[0009] The above-mentioned tungsten-rhenium thermocouple indication error verification device is characterized in that: a funnel inlet is provided on one side of the sealing cover, and a sealing plug is provided on the funnel inlet; the depth of the funnel inlet is equal to the height of the sealing cover, and the funnel inlet communicates with the interior of the crucible.

[0010] The above-mentioned tungsten-rhenium thermocouple indication error verification device is characterized in that: the tungsten-rhenium thermocouple verification mechanism includes a high-temperature ceramic sleeve vertically arranged in a crucible and a verification fixing platform arranged on the top of the high-temperature ceramic sleeve and arranged in the sealing cover; the high-temperature ceramic sleeve and the verification fixing platform are integrally formed; the bottom of the thermocouple sleeve to be verified and the temperature control sleeve are flush with the bottom of the verification fixing platform, and the top of the thermocouple sleeve to be verified and the temperature control sleeve extend through the top of the verification fixing platform to the top of the verification fixing platform; the bottom of the thermocouple sleeve to be verified and the temperature control sleeve are in communication with the interior of the high-temperature ceramic sleeve.

[0011] The above-mentioned tungsten-rhenium thermocouple indication error verification device is characterized in that: the inlet pipe and the outlet pipe are both arranged on the verification fixing platform, and the interior of the verification fixing platform is respectively provided with an inlet channel and an outlet channel; the inlet pipe is connected to the interior of the high-temperature ceramic sleeve through the inlet channel inside the verification fixing platform; the outlet pipe is connected to the interior of the high-temperature ceramic sleeve through the outlet channel inside the verification fixing platform.

[0012] The above-mentioned tungsten-rhenium thermocouple indication error verification device is characterized in that: the thermocouple sheath to be verified and the temperature control thermocouple sheath are both connected to the verification fixing platform by fastening bolts, and the fastening bolts are fixed to the top of the verification fixing platform.

[0013] The above-mentioned tungsten-rhenium thermocouple indication error verification device is characterized in that: the inner diameter of the thermocouple sheath to be verified is larger than the diameter of the thermocouple to be verified; the inner diameter of the temperature control thermocouple sheath is larger than the diameter of the temperature control thermocouple.

[0014] The above-mentioned tungsten-rhenium thermocouple indication error verification device is characterized in that: the fixed frame includes a fixed base and a fixed bracket vertically arranged on the fixed base, and the fixed base and the fixed bracket are detachably connected.

[0015] The above-mentioned tungsten-rhenium thermocouple indication error verification device is characterized in that: the adjustable fixing base includes an adjustable fixing plate disposed on a fixed bracket, a positioning screw disposed on one side of the adjustable fixing plate for fixing the position of the adjustable fixing plate, and a connecting frame disposed on the other side of the adjustable fixing plate for fixing the thermocouple; the connecting frame and the fixing clamp are connected by a fastening screw; the fixing clamp is connected to the fastening screw by a horizontal fixing rod.

[0016] The above-mentioned tungsten-rhenium thermocouple indication error verification device is characterized in that: the temperature-controlling thermocouple in the temperature-controlling thermocouple sheath is connected to the temperature-controlling instrument; and the tungsten-rhenium thermocouple to be verified in the thermocouple sheath is connected to the high-precision data acquisition device.

[0017] The present invention also provides a method for periodically verifying the indication error of tungsten-rhenium thermocouples using a tungsten-rhenium thermocouple indication error verification device, characterized in that the method includes the following steps:

[0018] Step 1: Constructing an argon environment: Open the argon cylinder and supply argon gas into the interior of the high-temperature ceramic sleeve. Activate the gas sensor to detect the gas at the outlet of the gas pipe. When the gas sensor continuously detects oxygen, continue supplying argon gas into the interior of the high-temperature ceramic sleeve until the gas sensor can no longer detect oxygen, thus forming an argon environment inside the high-temperature ceramic sleeve.

[0019] Step 2: Place the solid standard sample and install the thermocouple: Place a solid standard sample with a mass of m grams into the crucible. Place a temperature-controlled thermocouple inside the temperature-controlled thermocouple sleeve and secure it with a thermocouple holder. Simultaneously, place a tungsten-rhenium thermocouple to be verified inside the thermocouple sleeve and secure it with a thermocouple holder. The depth to which both the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be verified extend into the crucible is h. The formula for calculating h is h = H - h1 / 2, where H is the depth of the crucible, and h1 is the depth to which the solid standard sample becomes a liquid standard sample after heating.

[0020] Step 3: Prepare a standard temperature source: Seal the openings of the thermocouple sheath and the temperature control thermocouple sheath with asbestos, then start the heating furnace to heat the crucible; observe the temperature reading on the temperature control instrument connected to the temperature control thermocouple. When the temperature reading remains constant, it is determined that the solid standard sample added to the crucible has completely melted; open the sealing plug, insert the funnel and add the solid standard sample back into the crucible, so that the standard sample in the crucible maintains a solid-liquid coexistence state. At this time, the temperature of the standard sample is constant at the melting point temperature. Use the solid-liquid coexistence standard sample in the crucible as the standard temperature source;

[0021] Step 4: Check the indication error of the tungsten-rhenium thermocouple to be checked. The process is as follows:

[0022] Step 401: Use a high-precision data acquisition device to collect data from the tungsten-rhenium thermocouple to be verified. Collect data every 2 minutes, collecting three sets of data. The average of the three sets of data is taken as the measurement result t of the tungsten-rhenium thermocouple to be verified. The indication error of the tungsten-rhenium thermocouple to be verified is Δt = tt. b ; where t b This refers to the melting point temperature of the standard sample.

[0023] Step 402: Continue to collect data from the tungsten-rhenium thermocouple to be checked using a high-precision data acquisition device. Collect data every 2 minutes for n minutes, collecting multiple sets of data. The maximum value among the multiple sets of data is t. max The minimum value among multiple sets of data is t. min The stability of the tungsten-rhenium thermocouple to be verified is the difference between the maximum and minimum values ​​in multiple sets of data, i.e., t. max -t min Where n is a positive integer greater than 10.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. This invention places a temperature-controlled thermocouple and a tungsten-rhenium thermocouple to be verified simultaneously into a crucible. A heating furnace provides a heat source to the crucible, melting the solid metal inside. This melts the metal and serves as the temperature source for both the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be verified. A standard metal sample is used to verify the indication error of the tungsten-rhenium thermocouple to be verified. This invention is not limited by the geographical location or laboratory of traditional thermocouple verification, does not require periodic traceability, has a simple structure, and is easy to use.

[0026] 2. The present invention utilizes an inlet pipe and an outlet pipe to create an argon gas environment inside the tungsten-rhenium thermocouple verification mechanism, thereby preventing oxidation of the tungsten-rhenium thermocouple to be verified during the verification process, which would affect its use.

[0027] 3. This invention uses the melting point of a standard metal sample as a temperature standard value to provide a stable standard temperature source for the indication error of the tungsten-rhenium thermocouple to be verified. Compared with traditional tube furnaces, liquid metal as a standard temperature source is more stable and safer. At the same time, it is not limited by the region and laboratory of traditional thermocouple verification, and does not require periodic traceability or interim verification. It can realize online and on-site traceability, meeting the needs of industrial metrology and testing.

[0028] 4. This invention does not require a thermostat to maintain the temperature during the traditional indication error verification process. It only requires installing the thermocouple to be verified in a high-temperature ceramic furnace. Once the temperature of the thermocouple remains constant, data collection can begin, making the operation simple.

[0029] In summary, this invention places both the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be verified into a crucible simultaneously. A heating furnace provides a heat source to the crucible, melting the solid metal inside. This melts the metal and serves as the temperature source for both the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be verified. A standard metal sample is used to verify the indication error of the tungsten-rhenium thermocouple to be verified. This method is not limited by the geographical location or laboratory of traditional thermocouple verification and does not require periodic traceability. The melting point of the standard metal sample is used as the temperature standard value, providing a stable standard temperature source for the indication error of the tungsten-rhenium thermocouple to be verified. Compared with traditional tube furnaces, liquid metal as a standard temperature source is more stable and safer.

[0030] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0031] Figure 1 This is a schematic diagram showing the positional relationship between the heating mechanism and the tungsten-rhenium thermocouple verification mechanism of the present invention.

[0032] Figure 2 This is a schematic diagram of the thermocouple mounting bracket of the present invention.

[0033] Figure 3 This is a schematic diagram showing the connection relationship between the fixing clamp and the horizontal fixing rod of the present invention.

[0034] Figure 4 This is a flowchart of the method of the present invention.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1—Heating furnace; 2—Crucible; 3—Sealing lid;

[0037] 4—Thermocouple sheath; 5—Thermocouple sheath to be verified; 6—Fastening bolts;

[0038] 7—Verification mounting plate; 8—Sealing plug; 9—Adjustable mounting plate;

[0039] 10—Fixing clamp; 11—High-temperature ceramic sleeve; 12—Exhaust pipe;

[0040] 13—Intake pipe; 16—Fixed bracket; 17—Positioning screw;

[0041] 18—Connecting bracket; 19—Fastening screw; 20—Fixed base;

[0042] 21—Horizontal fixed rod. Detailed Implementation

[0043] like Figure 1 , Figure 2 and Figure 3 The device shown is a tungsten-rhenium thermocouple indication error verification device, including a heating mechanism, a tungsten-rhenium thermocouple verification mechanism disposed in the heating mechanism, and a thermocouple fixing frame disposed on one side of the heating mechanism and cooperating with the tungsten-rhenium thermocouple verification mechanism;

[0044] The heating mechanism includes a heating furnace 1 and a crucible 2 vertically arranged on the heating furnace 1, and a sealing cover 3 is provided on the top of the heating furnace 1;

[0045] The bottom of the tungsten-rhenium thermocouple verification mechanism is in close contact with the bottom of the crucible 2. The top of the tungsten-rhenium thermocouple verification mechanism extends through the sealing cover 3 to the top of the sealing cover 3. Multiple thermocouple sleeves 5 to be verified and one temperature-controlled thermocouple sleeve 4 are vertically arranged inside the tungsten-rhenium thermocouple verification mechanism. The bottoms of both the thermocouple sleeves 5 and the temperature-controlled thermocouple sleeve 4 are flush with the bottom of the sealing cover 3. The tops of both the thermocouple sleeves 5 and the temperature-controlled thermocouple sleeve 4 extend through the top of the tungsten-rhenium thermocouple verification mechanism to the top of the tungsten-rhenium thermocouple verification mechanism. The bottoms of both the thermocouple sleeves 5 and the temperature-controlled thermocouple sleeve 4 are connected to the interior of the tungsten-rhenium thermocouple verification mechanism.

[0046] The upper part of the tungsten-rhenium thermocouple verification mechanism is symmetrically provided with an inlet pipe 13 and an outlet pipe 12. An argon cylinder is connected to the inlet pipe 13, and a gas sensor is provided at the opening of the outlet pipe 12. Both the inlet pipe 13 and the outlet pipe 12 are connected to the interior of the tungsten-rhenium thermocouple verification mechanism.

[0047] The thermocouple holder includes a holder body disposed on one side of the crucible 2, an adjustable mounting base disposed on the holder body and movable along the height direction of the holder body, and a mounting clip 10 disposed on the adjustable mounting base.

[0048] This invention places a temperature-controlled thermocouple and a tungsten-rhenium thermocouple to be verified simultaneously into a crucible 2. A heating furnace 1 provides a heat source to the crucible 2, melting the solid metal inside the crucible 2. This melts the metal and serves as the temperature source for both the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be verified. A standard metal sample is used to verify the indication error of the tungsten-rhenium thermocouple to be verified. This invention is not limited by the geographical location or laboratory of traditional thermocouple verification, does not require periodic traceability, has a simple structure, and is easy to use.

[0049] The present invention utilizes the inlet pipe 13 and the outlet pipe 12 to construct an argon gas environment inside the tungsten-rhenium thermocouple verification mechanism, thereby avoiding oxidation during the verification process of the tungsten-rhenium thermocouple to be verified, which would affect its use.

[0050] It should be noted that the heating furnace 1 is used to provide a heat source; the crucible 2 is used to hold metal particles and molten metal; the sealing cover 3 is a special sealing cover that is easy to disassemble; the temperature control thermocouple sleeve 4 is used to insert a temperature control thermocouple, and the temperature control thermocouple and the temperature control instrument are connected to form a temperature control device, which is used to monitor the temperature of the molten metal; the thermocouple sleeve 5 to be verified is used to insert a tungsten-rhenium thermocouple to be verified.

[0051] like Figure 1 As shown, in this embodiment, a funnel inlet is also provided on one side of the sealing cover 3, and a sealing plug 8 is provided on the funnel inlet; the depth of the funnel inlet is equal to the height of the sealing cover 3, and the funnel inlet is in communication with the interior of the crucible 2.

[0052] In actual use, the funnel inlet is used to insert the funnel. When no solid metal is needed, the sealing plug 8 is closed. When metal particles need to be added, the sealing plug 8 is opened, the funnel is inserted, and the metal particles are added into the molten metal along the funnel. The funnel is a high-temperature resistant ceramic funnel used to add metal particles.

[0053] like Figure 1As shown, in this embodiment, the tungsten-rhenium thermocouple verification mechanism includes a high-temperature ceramic sleeve 11 vertically disposed within the crucible 2 and a verification fixing platform 7 disposed on the top of the high-temperature ceramic sleeve 11 and arranged within the sealing cover 3. The high-temperature ceramic sleeve 11 and the verification fixing platform 7 are integrally formed. The bottoms of the thermocouple sheath 5 to be verified and the temperature control sheath 4 are flush with the bottom of the verification fixing platform 7. The tops of the thermocouple sheath 5 to be verified and the temperature control sheath 4 extend through the top of the verification fixing platform 7 to the top of the verification fixing platform 7. The bottoms of the thermocouple sheath 5 to be verified and the temperature control sheath 4 are connected to the interior of the high-temperature ceramic sleeve 11.

[0054] In actual use, the verification fixing platform 7 is a sleeve structure made of metal, which is connected to the high-temperature ceramic sleeve 11 with high-temperature sealant; the high-temperature ceramic sleeve 11 is used to isolate the molten metal and the tungsten-rhenium thermocouple to be verified.

[0055] like Figure 1 As shown, in this embodiment, the air inlet pipe 13 and the air outlet pipe 12 are both arranged on the verification station 7. The verification station 7 has an air inlet channel and an air outlet channel respectively. The air inlet pipe 13 is connected to the interior of the high-temperature ceramic sleeve 11 through the air inlet channel inside the verification station 7. The air outlet pipe 12 is connected to the interior of the high-temperature ceramic sleeve 11 through the air outlet channel inside the verification station 7.

[0056] like Figure 1 As shown, in this embodiment, both the thermocouple sheath 5 to be checked and the temperature control thermocouple sheath 4 are connected to the checking platform 7 by fastening bolts 6, and the fastening bolts 6 are fixed to the top of the checking platform 7.

[0057] In this embodiment, the inner diameter of the thermocouple sheath 5 to be checked is larger than the diameter of the thermocouple to be checked; the inner diameter of the temperature control thermocouple sheath 4 is larger than the diameter of the temperature control thermocouple.

[0058] like Figure 2 As shown in this embodiment, the fixed frame includes a fixed base 20 and a fixed bracket 16 vertically arranged on the fixed base 20, and the fixed base 20 and the fixed bracket 16 are detachably connected.

[0059] like Figure 2 As shown, in this embodiment, the adjustable fixing base includes an adjustable fixing plate 9 disposed on the fixed bracket 16, a positioning screw 17 disposed on one side of the adjustable fixing plate 9 and used to fix the position of the adjustable fixing plate 9, and a connecting frame 18 disposed on the other side of the adjustable fixing plate 9 and used to fix the thermocouple. The connecting frame 18 and the fixing clamp 10 are connected by a fastening screw 19. The fixing clamp 10 is connected to the fastening screw 19 by a horizontal fixing rod 21.

[0060] In actual use, the fixing frame is used to support and position the thermocouple; the fixing clamp 10 is used to hold the thermocouple; the fixing clamp 10 is provided with a locking buckle to lock the fixing clamp 10 and fix the position of the thermocouple. Figure 2 As shown, the connecting frame 18 has a tapered structure on the side near the adjustable fixing plate 9, which, together with the fastening screw 19, positions the horizontal fixing rod 21 horizontally. The adjustable fixing plate 9 has a U-shaped structure, and the positioning screw 17 passes through one vertical section of the adjustable fixing plate 9 and the fixing bracket 16 in sequence, and then emerges from the other vertical section. The positioning screw 17 and the adjustable fixing plate 9 are connected by a thread. The fixing bracket 16 has a moving groove for the positioning screw 17 to move, and the moving groove is arranged along the height direction of the fixing bracket 16. The positioning screw 17 moves up and down in the moving groove to realize the up and down movement of the entire adjustable fixing seat. After the height is determined, the height is fixed by the threaded connection between the positioning screw 17 and the adjustable fixing plate 9.

[0061] In this embodiment, the temperature-controlling thermocouple in the temperature-controlling thermocouple sleeve 4 is connected to the temperature control instrument; the tungsten-rhenium thermocouple to be verified in the thermocouple sleeve 5 is connected to the high-precision data acquisition device.

[0062] like Figures 1 to 4 The method shown is a tungsten-rhenium thermocouple indication error period verification device for period verification of tungsten-rhenium thermocouple indication error, the method comprising the following steps:

[0063] Step 1: Constructing an argon environment: Open the argon cylinder and supply argon gas into the interior of the high-temperature ceramic sleeve 11. Activate the gas sensor to detect the gas at the outlet of the gas pipe 12. When the gas sensor continuously detects oxygen, continue supplying argon gas into the interior of the high-temperature ceramic sleeve 11 until the gas sensor can no longer detect oxygen, thus forming an argon environment inside the high-temperature ceramic sleeve 11.

[0064] Step 2: Place the solid standard sample and install the thermocouple: Place the solid standard sample with a mass of m grams into crucible 2. Place a temperature-controlled thermocouple into the temperature-controlled thermocouple sleeve 4 and fix it with a thermocouple holder. At the same time, place the tungsten-rhenium thermocouple to be verified into the thermocouple sleeve 5 and fix it with a thermocouple holder. The depth to which the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be verified extend into crucible 2 is h. The formula for calculating h is h = H - h1 / 2, where H is the depth of crucible 2; h1 is the depth of the solid standard sample after heating into a liquid standard sample.

[0065] Step 3: Prepare a standard temperature source: Seal the openings of the thermocouple sheath 5 and the temperature control thermocouple sheath 4 with asbestos, and then start the heating furnace 1 to heat the crucible 2; observe the temperature reading on the temperature control instrument connected to the temperature control thermocouple. When the temperature reading remains constant, it is determined that the solid standard sample added to the crucible 2 has completely melted; open the sealing plug 8, insert the funnel and add the solid standard sample back into the crucible 2, so that the standard sample in the crucible 2 maintains a solid-liquid coexistence state. At this time, the temperature of the standard sample is constant at the melting point temperature. Use the solid-liquid coexistence standard sample in the crucible 2 as the standard temperature source;

[0066] Step 4: Check the indication error of the tungsten-rhenium thermocouple to be checked. The process is as follows:

[0067] Step 401: Use a high-precision data acquisition device to collect data from the tungsten-rhenium thermocouple to be verified. Collect data every 2 minutes, collecting three sets of data. The average of the three sets of data is taken as the measurement result t of the tungsten-rhenium thermocouple to be verified. The indication error of the tungsten-rhenium thermocouple to be verified is Δt = tt. b ; where t b This refers to the melting point temperature of the standard sample.

[0068] Step 402: Continue to collect data from the tungsten-rhenium thermocouple to be checked using a high-precision data acquisition device. Collect data every 2 minutes for n minutes, collecting multiple sets of data. The maximum value among the multiple sets of data is t. max The minimum value among multiple sets of data is t min The stability of the tungsten-rhenium thermocouple to be verified is the difference between the maximum and minimum values ​​in multiple sets of data, i.e., t. max -t min Where n is a positive integer greater than 10.

[0069] In step one, after an argon environment is formed inside the high-temperature ceramic sleeve 11, in order to maintain the argon environment inside the high-temperature ceramic sleeve 11, the argon cylinder continuously supplies argon into the high-temperature ceramic sleeve 11 until the verification is completed.

[0070] This invention utilizes the melting point of a standard metal sample as a temperature standard value to provide a stable standard temperature source for the indication error of the tungsten-rhenium thermocouple to be verified. Compared with traditional tube furnaces, liquid metal as a standard temperature source is more stable and safer. At the same time, it is not limited by the region and laboratory of traditional thermocouple verification, and does not require periodic traceability or interim verification. It can realize online and on-site traceability, meeting the needs of industrial metrology and testing.

[0071] This invention eliminates the need for a thermostat to maintain temperature during the traditional indication error verification process. Instead, the thermocouple to be verified is simply installed in a high-temperature ceramic furnace. Once the temperature of the thermocouple remains constant, data collection begins, making the operation simple.

[0072] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A device for checking the indication error of a tungsten-rhenium thermocouple, characterized in that: It includes a heating mechanism, a tungsten-rhenium thermocouple checking mechanism arranged in the heating mechanism, and a thermocouple fixing frame arranged on one side of the heating mechanism and matched with the tungsten-rhenium thermocouple checking mechanism; The heating mechanism comprises a heating furnace (1) and a crucible (2) vertically arranged on the heating furnace (1), and a sealing cover (3) is arranged on the top of the heating furnace (1); The bottom of the tungsten-rhenium thermocouple verification mechanism is in close contact with the bottom of the crucible (2), and the top of the tungsten-rhenium thermocouple verification mechanism passes through the sealing cover (3) and extends to the top of the sealing cover (3); a plurality of thermocouple sleeves (5) to be verified and a temperature-controlling sleeve (4) are vertically arranged in the tungsten-rhenium thermocouple verification mechanism, the bottoms of the thermocouple sleeves (5) to be verified and the temperature-controlling sleeve (4) are both flush with the bottom of the sealing cover (3), and the tops of the thermocouple sleeves (5) to be verified and the temperature-controlling sleeve (4) pass through the top of the tungsten-rhenium thermocouple verification mechanism and extend to the top of the tungsten-rhenium thermocouple verification mechanism; the bottoms of the thermocouple sleeves (5) to be verified and the temperature-controlling sleeve (4) are both connected to the interior of the tungsten-rhenium thermocouple verification mechanism; An air inlet pipe (13) and an air outlet pipe (12) are symmetrically arranged on the upper part of the tungsten-rhenium thermocouple verification mechanism, an argon gas bottle is connected to the air inlet pipe (13), and a gas sensor is arranged at the pipe mouth of the air outlet pipe (12); the air inlet pipe (13) and the air outlet pipe (12) are both connected to the interior of the tungsten-rhenium thermocouple verification mechanism; The thermocouple fixing frame comprises a fixing frame body arranged on one side of the crucible (2), an adjustable fixing seat arranged on the fixing frame body and movable along the height direction of the fixing frame body, and a fixing clamp (10) arranged on the adjustable fixing seat.

2. The device for checking the indication error of a tungsten-rhenium thermocouple according to claim 1, characterized in that: A funnel socket is also provided on one side of the sealing cover (3), and a sealing plug (8) is provided on the funnel socket; the depth of the funnel socket is equal to the height of the sealing cover (3), and the funnel socket is connected to the interior of the crucible (2).

3. The device for checking the indication error of a tungsten-rhenium thermocouple according to claim 2, characterized in that: The tungsten-rhenium thermocouple verification mechanism comprises a high-temperature ceramic sleeve (11) vertically arranged in a crucible (2) and a verification fixing platform (7) arranged on the top of the high-temperature ceramic sleeve (11) and arranged in the sealing cover (3), wherein the high-temperature ceramic sleeve (11) and the verification fixing platform (7) are integrally formed; the bottoms of the thermocouple sleeve (5) to be verified and the temperature-controlling thermocouple sleeve (4) are both flush with the bottom of the verification fixing platform (7), and the tops of the thermocouple sleeve (5) to be verified and the temperature-controlling thermocouple sleeve (4) pass through the top of the verification fixing platform (7) and extend to the top of the verification fixing platform (7); the bottoms of the thermocouple sleeve (5) to be verified and the temperature-controlling thermocouple sleeve (4) are both connected to the interior of the high-temperature ceramic sleeve (11).

4. The device for checking the indication error of a tungsten-rhenium thermocouple according to claim 3, characterized in that: The air inlet pipe (13) and the air outlet pipe (12) are both arranged on the inspection fixing platform (7), and an air inlet channel and an air outlet channel are respectively provided inside the inspection fixing platform (7). The air inlet pipe (13) is connected to the interior of the high-temperature ceramic sleeve (11) through the air inlet channel inside the inspection fixing platform (7); and the air outlet pipe (12) is connected to the interior of the high-temperature ceramic sleeve (11) through the air outlet channel inside the inspection fixing platform (7).

5. The device for checking the indication error of a tungsten-rhenium thermocouple according to claim 3, characterized in that: The thermocouple sleeve (5) to be checked and the temperature-controlling thermocouple sleeve (4) are both connected to the checking fixing platform (7) via fastening bolts (6), and the fastening bolts (6) are fixed on the top of the checking fixing platform (7).

6. The device for checking the indication error of a tungsten-rhenium thermocouple according to claim 3, characterized in that: The inner diameter of the thermocouple sleeve (5) to be checked is larger than the diameter of the thermocouple to be checked; and the inner diameter of the temperature-controlling thermocouple sleeve (4) is larger than the diameter of the temperature-controlling thermocouple.

7. The device for checking the indication error of a tungsten-rhenium thermocouple according to claim 3, characterized in that: The fixed frame body comprises a fixed base (20) and a fixed bracket (16) vertically arranged on the fixed base (20); the fixed base (20) and the fixed bracket (16) are detachably connected.

8. The device for checking the indication error of a tungsten-rhenium thermocouple according to claim 7, characterized in that: The adjustable fixing seat comprises an adjustable fixing plate (9) arranged on a fixing bracket (16), a positioning screw (17) arranged on one side of the adjustable fixing plate (9) and used to fix the position of the adjustable fixing plate (9), and a connecting frame (18) arranged on the other side of the adjustable fixing plate (9) and used to fix the thermocouple, wherein the connecting frame (18) and the fixing clamp (10) are connected via a fastening screw (19); the fixing clamp (10) is connected to the fastening screw (19) via a horizontal fixing rod (21).

9. The device for checking the indication error of a tungsten-rhenium thermocouple according to claim 7, characterized in that: The temperature-controlling thermocouple in the temperature-controlling thermocouple sleeve (4) is connected to a temperature-controlling instrument; and the tungsten-rhenium thermocouple to be checked in the thermocouple sleeve to be checked (5) is connected to a high-precision data collector.

10. The method for period checking the indication error of a tungsten-rhenium thermocouple according to claim 9, characterized in that: The method comprises the following steps: Step 1, constructing an argon environment: opening an argon gas bottle, delivering argon gas to the interior of the high-temperature ceramic sleeve (11), starting a gas sensor to detect the gas at the outlet of the gas outlet pipe (12), and when the gas sensor continues to detect oxygen, continuing to deliver argon gas to the interior of the high-temperature ceramic sleeve (11) until the gas sensor can no longer detect oxygen, thereby forming an argon gas environment inside the high-temperature ceramic sleeve (11); Step 2, placing a solid standard sample and installing a thermocouple: placing a solid standard sample with a mass of m grams into a crucible (2), placing a temperature-controlled thermocouple into a temperature-controlled thermocouple sleeve (4) and fixing it with a thermocouple fixing frame, and placing a tungsten-rhenium thermocouple to be checked into a thermocouple sleeve (5) to be checked and fixing it with a thermocouple fixing frame; the temperature-controlled thermocouple and the tungsten-rhenium thermocouple to be checked are both inserted into the crucible (2) to a depth of h, and the calculation formula of h is h=H-h1 / 2, wherein H is the depth of the crucible (2); h1 is the depth at which the solid standard sample becomes a liquid standard sample after being heated; Step 3, making a standard temperature source: using asbestos to seal the pipe openings of the thermocouple sleeve (5) to be checked and the temperature-controlling thermocouple sleeve (4), and then starting the heating furnace (1) to heat the crucible (2); observing the temperature reading on the temperature-controlling instrument connected to the temperature-controlling thermocouple, when the temperature reading is constant, it is judged that the solid standard sample added to the crucible (2) has been completely melted; opening the sealing plug (8), inserting the funnel to add the solid standard sample to the crucible (2), so that the standard sample in the crucible (2) maintains the form of solid and liquid coexistence, at this time the temperature of the standard sample is constant at the melting point temperature, and the solid and liquid coexisting standard sample in the crucible (2) is used as the standard temperature source; Step 4: Check the indication error of the tungsten-rhenium thermocouple to be checked. The process is as follows: Step 401: Use a high-precision data collector to collect data on the tungsten-rhenium thermocouple to be checked, collect data every 2 minutes, collect three sets of data, and use the average value of the three sets of data as the measurement result t of the tungsten-rhenium thermocouple to be checked. The indication error of the tungsten-rhenium thermocouple to be checked is Δt=tt b ; where t b is the melting point temperature of the standard sample; Step 402: Continue to use the high-precision data collector to collect data on the tungsten-rhenium thermocouple to be checked, collect data every 2 minutes, collect data continuously for nmin minutes, collect multiple sets of data, and the maximum value among the multiple sets of data is t max , the minimum value among multiple sets of data is t min , then the stability of the tungsten-rhenium thermocouple to be checked is the difference between the maximum and minimum values ​​in multiple sets of data, that is, t max -t min ; Wherein, n is a positive integer greater than 10.

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