A furnace outer positioner for testing temperature field of inexpensive metal thermocouple calibrating furnace

Abstract

The utility model discloses a kind of low metal thermocouple calibrating furnace temperature field test furnace outer positioner, it is related to thermocouple calibration technical field.Set up telescopic support mechanism between supporting base and horizontal positioning block, two positioning pipe holes are set in the left side end of long positioning block, two standard couple holes one are set in the right side end of long positioning block, two standard couple holes one are communicated with two positioning pipe holes respectively, two standard couple holes two are set in horizontal positioning block.The device is provided with long positioning block, and the constraint length of standard couple position for testing is increased;The device is also provided with not easy to wear horizontal positioning block and telescopic support mechanism, horizontal positioning block is connected with long positioning block by connecting bolt, further restricts the position of standard couple for testing, reduces the uncertainty of calibrating furnace temperature field test result caused by position deviation of standard couple temperature measuring point, and the temperature field of low metal thermocouple calibrating furnace can be more accurately tested, characterized and evaluated.

Description

Technical Field

[0001] This utility model relates to the field of thermocouple calibration technology, and in particular to an external positioner for testing the temperature field of a base metal thermocouple calibration furnace. Background Technology

[0002] A thermocouple is a thermometer made of two conductors of different materials based on the Seebeck effect. A thermocouple calibration furnace (or simply calibration furnace) is an electrically heated device that provides a heat source for thermocouple calibration. It mainly consists of a furnace tube, heating element, insulation layer, and outer shell. The heating element is wound around the furnace tube, and a temperature control couple is installed inside the furnace tube. The temperature inside the furnace tube is regulated by a temperature controller based on the deviation between the temperature measured by the temperature control couple and the set value, by adjusting the power of the heating element. Thermocouple calibration furnaces are usually placed horizontally, also known as horizontal thermocouple calibration furnaces.

[0003] Calibration furnaces can be divided into precious metal thermocouple calibration furnaces (hereinafter referred to as precious metal furnaces) and base metal thermocouple calibration furnaces (hereinafter referred to as base metal furnaces). The furnace tube size of a precious metal furnace is typically Φ20×600mm (inner diameter×length, the same below), while the furnace tube size of a base metal furnace is typically Φ40×600mm. The temperature field distribution of the calibration furnace is one of the important sources of thermocouple calibration uncertainty. According to the requirements of the national standard JJF 1184-2024, "Technical Specification for Temperature Field Testing of Thermocouple Calibration Furnaces," the temperature field of the calibration furnace must be retested periodically, with an interval generally not exceeding one year.

[0004] During temperature field testing of base metal thermocouple furnaces, a cup-type or perforated isothermal block is placed inside the furnace tube, and a positioning block is placed at the furnace opening at the measuring end of the calibration furnace. A positioning tube, with one end sealed, is inserted to the bottom of the isothermal block. However, due to several issues, the positioning tube is suspended within the cup-type isothermal block, as it provides no support. Furthermore, there is a clearance between the opening in the positioning block and the positioning tube. Since the positioning block is typically made of high-temperature resistant, easily worn mullite, this clearance increases over time. Consequently, it becomes difficult for the positioning tube to be parallel to the central axis of the furnace tube, leading to increased uncertainty in the temperature field measurement results and affecting the testing, characterization, and evaluation of the temperature field performance of the thermocouple calibration furnace.

[0005] Therefore, this application proposes an external positioner for testing the temperature field of a base metal thermocouple calibration furnace to solve the above problems. Utility Model Content

[0006] The purpose of this invention is to provide an external positioner for testing the temperature field of a base metal thermocouple calibration furnace, which solves the technical problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution: an external positioning device for temperature field testing of a base metal thermocouple calibration furnace, comprising a support base, connecting bolts, a horizontal positioning block and a long positioning block, wherein the outer diameters of the horizontal positioning block and the long positioning block are the same, the left end of the long positioning block is inserted into the furnace tube of the base metal thermocouple calibration furnace, the horizontal positioning block is located above the support base, a telescopic support mechanism is provided between the support base and the horizontal positioning block, the long positioning block is located to the left of the horizontal positioning block, the long positioning block has two connecting through holes one, and the horizontal positioning block has two connecting through holes two, the connecting through holes one and two are coaxially arranged, the right end of the connecting bolt passes through the connecting through holes one and two in sequence and is connected with a nut, the long positioning block... Two positioning tube holes are provided on the left side end of the positioning block. One of the positioning tube holes is coaxially arranged with the elongated positioning block. Two standard pairs of holes are provided on the right side end of the elongated positioning block. The two standard pairs of holes are respectively connected to the two positioning tube holes. The inner diameter of the positioning tube hole is larger than the inner diameter of the standard pairs of holes. Two standard pairs of holes are provided on the horizontal positioning block. The two standard pairs of holes are respectively coaxially arranged with the two standard pairs of holes. The standard pairs of holes are the same size as the standard pairs of holes. A blind hole is provided on the right side end of the horizontal positioning block. A spirit level is provided in the blind hole. The central axis of the blind hole is parallel to the central axis of the horizontal positioning block. A positioning ring is provided on the outer wall of the elongated positioning block. The positioning ring is integrally formed with the elongated positioning block. The outer diameter of the positioning ring is larger than the outer diameter of the elongated positioning block.

[0008] The telescopic support mechanism includes a telescopic outer cylinder, a clamping plate, a telescopic adjusting rod, an adjusting ring, and a V-shaped bracket.

[0009] Preferably, the outer side wall of the horizontal positioning block is provided with a plurality of blind grooves, at least three of which are provided, and the central axis of the blind grooves is parallel to the central axis of the horizontal positioning block.

[0010] Preferably, the telescopic outer cylinder is fixed on the support base, and a plurality of clamping plates are provided, all of which are fixed to the upper end of the telescopic outer cylinder. The lower end of the telescopic adjusting rod extends into the telescopic outer cylinder, and the upper end of the telescopic adjusting rod is fixedly connected to the lower end of the V-shaped bracket. The adjusting ring is sleeved on the telescopic outer cylinder, and the plurality of clamping plates are threadedly connected to the adjusting ring.

[0011] Preferably, the elongated positioning block is made of mullite, high-alumina brick, or corundum; the horizontal positioning block is made of transparent materials such as quartz glass or ordinary glass, or it can be made of metal such as iron, aluminum, copper, steel, or corundum; the connecting bolt is made of stainless steel or corundum; and the V-shaped bracket is made of aluminum alloy or stainless steel.

[0012] Compared with related technologies, the external positioner for temperature field testing of base metal thermocouple calibration furnace provided by this utility model has the following advantages:

[0013] This invention provides an external positioner for testing the temperature field of a base metal thermocouple calibration furnace. The device includes an elongated positioning block, increasing the constraint length on the position of the standard thermocouple being tested and reducing the deviation of the standard thermocouple caused by the clearance between the positioning block opening and the testing positioning tube and the standard thermocouple. It also avoids significant additional interference to the temperature field inside the furnace. The device further includes a wear-resistant horizontal positioning block and a telescopic support mechanism. The horizontal positioning block is connected to the elongated positioning block via connecting bolts, further constraining the position of the standard thermocouple. A spirit level is also provided on the horizontal positioning block, directly displaying the levelness, and the telescopic support mechanism facilitates easy adjustment of the horizontal positioning block's levelness, providing a "ruler" for ensuring the standard thermocouple is parallel to the furnace tube's central axis. This invention reduces the uncertainty in the temperature field test results of the calibration furnace caused by positional deviations of the standard thermocouple's temperature measurement point, enabling more accurate testing, characterization, and evaluation of the temperature field of the base metal thermocouple calibration furnace. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the installation for testing the temperature field of an existing cup-type isothermal block base metal inductor furnace according to this utility model.

[0015] Figure 2 This is a three-dimensional structural diagram of the present invention;

[0016] Figure 3 This is a three-dimensional structural diagram of the present invention from another angle;

[0017] Figure 4 This is a cross-sectional view of the elongated positioning block and the horizontal positioning block of this utility model after they are fitted together.

[0018] Figure 5 This is a schematic diagram of the exploded structure of the telescopic outer cylinder of this utility model;

[0019] Figure 6 for Figure 5 Enlarged view of a portion of point A in the middle;

[0020] Figure 7 This is a three-dimensional structural diagram of the elongated positioning block of this utility model;

[0021] Figure 8 This is a schematic diagram of the three-dimensional structure of the horizontal positioning block of this utility model.

[0022] In the diagram: 1. Furnace tube; 2. Temperature control end positioning block; 3. Cup-type temperature equalization block; 4. Measuring end positioning block; 5. Testing positioning tube; 6. Testing standard coupler; 7. Support base; 8. Telescopic outer cylinder; 9. Clamping plate; 10. Telescopic adjustment rod; 11. Adjustment ring; 12. V-shaped bracket; 13. Horizontal positioning block; 14. Long positioning block; 15. Positioning ring; 16. Connecting bolt; 17. Positioning tube hole; 18. Connecting through hole one; 19. Standard coupler hole one; 20. Standard coupler hole two; 21. Blind slot; 22. Horizontal bubble; 23. Connecting through hole two; 24. Blind hole. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0024] Example 1

[0025] Please see Figure 1 , Figure 1This is a cross-sectional view of the existing cup-type isothermal block base metal inductor furnace temperature field testing installation structure. It includes a furnace tube 1, a testing positioning tube 5, and a testing standard coupler 6. The furnace tube 1 has an inner diameter of 40mm and a length of 600mm. Temperature control end positioning blocks 2 and measuring end positioning blocks 4 are respectively installed at the left and right ends of the furnace tube 1. A cup-type isothermal block 3 is installed inside the furnace tube 1, with its inner bottom surface located at the axial center of the furnace tube. The left end of the testing positioning tube 5 passes through the measuring end positioning block 4 and extends to the cup-type isothermal block 3. The testing standard coupler 6... The left end extends into the inner side of the test positioning tube 5. The left ends of the test positioning tube 5 and the test standard coupler 6 are suspended in the cup-shaped temperature equalization block 3 without any supporting structure. On the other hand, the measuring end positioning block 4 is relatively short, and there is a fitting gap between its opening and the test positioning tube 5. Moreover, the measuring end positioning block 4 is usually made of a high-temperature resistant and easily worn material, such as mullite. With long-term use, the diameter of its hole gradually increases, which gradually increases the fitting gap between the opening of the measuring end positioning block 4 and the test positioning tube 5. Therefore, the position of the sensing point of the test standard coupler 6 inserted in the test positioning tube 5 is usually difficult to control. During axial temperature field measurement, the trajectory of the sensing point of the test standard coupler 6 is not parallel to the central axis of the furnace tube 1; during radial temperature field measurement, the distance between the sensing points of the two test standard couplers 6 does not meet the 14mm requirement of the metrological test specification. In the existing technology, the temperature sensing point of the standard thermocouple 6 used for testing does not meet the requirements, which leads to an increase in the uncertainty of the temperature field test of the calibration furnace, and makes it impossible to accurately test, characterize and evaluate the temperature field of the base metal thermocouple calibration furnace.

[0026] Please see Figures 2-7This utility model provides a technical solution: an external positioning device for temperature field testing of a base metal thermocouple calibration furnace, comprising a support base 7, connecting bolts 16, a horizontal positioning block 13 and a long positioning block 14. The outer diameter of the long positioning block 14 is 39mm, the outer diameter of the positioning ring 15 is 50mm, the length of the long positioning block 14 is 110mm, the length of the positioning ring 15 is 10mm, the length of the horizontal positioning block 13 is 80mm, and the outer diameters of the horizontal positioning block 13 and the long positioning block 14 are the same. The left end of the long positioning block 14 is inserted into the furnace tube 1 of the base metal thermocouple calibration furnace. The horizontal positioning block 13 is located above the support base 7. A telescopic support mechanism is provided between the horizontal positioning block 13 and the elongated positioning block 14. The elongated positioning block 14 is located to the left of the horizontal positioning block 13. The elongated positioning block 14 has two connecting through holes 18, and the horizontal positioning block 13 has two connecting through holes 23. The connecting through holes 18 and 23 are coaxially arranged, and their inner diameter is 7mm. The right end of the connecting bolt 16 passes through the connecting through holes 18 and 23 and is connected with a nut. The connecting bolt 16 is an M6 type, and its thread length is 200mm. The left end of the elongated positioning block 14 has... There are two positioning tube holes 17, which are used to place the test positioning tube 5 for testing the temperature field of the base metal thermocouple calibration furnace. The inner diameter of the positioning tube hole 17 is larger than the outer diameter of the test positioning tube 5. One of the positioning tube holes 17 is coaxially arranged with the elongated positioning block 14. Two standard thermocouple holes 19 are opened on the right side of the elongated positioning block 14. The two standard thermocouple holes 19 are connected to the two positioning tube holes 17 respectively. The inner diameter of the positioning tube hole 17 is larger than the inner diameter of the standard thermocouple holes 19. Two standard thermocouple holes 20 are opened on the horizontal positioning block 13. The standard thermocouple holes 20 are through holes. The two standard thermocouple holes 19 are coaxially arranged with the two standard thermocouple holes 20 respectively. The second quasi-couple hole 20 has the same size. The first standard couple hole 19 and the second standard couple hole 20 are used to place the test standard couple 6 for the temperature field test of the base metal thermocouple calibration furnace. The inner diameter of the first standard couple hole 19 and the second standard couple hole 20 is larger than the outer diameter of the test standard couple 6. When the temperature field test of the calibration furnace is performed, the outer diameter of the test standard couple 6 is 4 mm, the outer diameter of the test positioning tube 5 is 8 mm and the length is 320 mm, the diameter of the positioning tube hole 17 on the long positioning block 14 is 9 mm, the diameter of the first standard couple hole 19 is 5 mm, the length of the positioning tube hole 17 on the long positioning block 14 is 70 mm, the length of the test standard couple 6 is 40 mm, and the radial distance between the two test positioning tubes 5 is 14 mm.A blind hole 24 is provided on the right end of the horizontal positioning block 13. A horizontal bubble 22 is provided in the blind hole 24. The central axis of the blind hole 24 is parallel to the central axis of the horizontal positioning block 13. The diameter of the horizontal bubble 22 is 6mm and the length of the horizontal bubble 22 is 24mm. The diameter of the blind hole 24 is 6.6mm and the depth of the blind hole 24 is 52mm.

[0027] A positioning ring 15 is provided on the outer wall of the elongated positioning block 14. The positioning ring 15 is integrally formed with the elongated positioning block 14. The outer diameter of the positioning ring 15 is larger than the inner diameter of the furnace tube 1. The positioning ring 15 is used to limit the length of the elongated positioning block 14 inserted into the furnace tube 1 during use.

[0028] The telescopic support mechanism includes a telescopic outer cylinder 8, clamping plates 9, a telescopic adjusting rod 10, an adjusting ring 11, and a V-shaped bracket 12. The telescopic outer cylinder 8 is fixed on the support base 7. Several clamping plates 9 are provided, and all clamping plates 9 are fixed to the upper end of the telescopic outer cylinder 8. The lower end of the telescopic adjusting rod 10 extends into the telescopic outer cylinder 8, and the upper end of the telescopic adjusting rod 10 is fixedly connected to the lower end of the V-shaped bracket 12. The adjusting ring 11 is sleeved on the telescopic outer cylinder 8, and several clamping plates 9 are threadedly connected to the adjusting ring 11. When in use, the adjusting ring 11 is loosened, and the height of the V-shaped bracket 12 is adjusted. After the position is determined, the adjusting ring 11 can be rotated. At this time, the V-shaped bracket 12 supports the horizontal positioning block 13, so that the central axis of the horizontal positioning block 13 and the long positioning block 14 coincides with the central axis of the furnace tube 1.

[0029] The elongated positioning block 14 is made of mullite, high-alumina brick or corundum; the horizontal positioning block 13 is made of transparent materials such as quartz glass or ordinary glass, or it can be made of metal iron, aluminum, copper, steel or corundum; the connecting bolt 16 is made of stainless steel or corundum; the V-shaped bracket 12 is made of aluminum alloy or stainless steel, which is lightweight and can withstand certain high temperatures.

[0030] The present invention effectively improves the test results of the temperature field of the base metal thermocouple calibration furnace. Compared with the case without the present invention, under the conditions of the first embodiment of the present invention, the axial temperature difference within 30 mm of the laboratory base metal thermocouple calibration furnace is reduced by 0.05℃, and the radial temperature difference of the axial center section (i.e. the inner bottom surface of the cup-type temperature equalization block 3) is reduced by 0.02℃.

[0031] Example 2

[0032] Please see Figure 8 The difference from Embodiment 1 is that the horizontal positioning block 13 has a number of blind slots 21, which are arranged in a circular array. There are at least three blind slots 21. The horizontal bubble 22 is cylindrical or cuboid in shape, and the corresponding blind slot 21 is semi-circular or cuboid in shape.

[0033] Working principle: In use, the connecting bolts 16 pass through the connecting through holes 18 and 23 in sequence to connect the elongated positioning block 14 and the horizontal positioning block 13. The test positioning tube 5 is placed in the positioning tube hole 17. The test standard couple 6 passes through the right end of the standard couple hole 20, and then through the standard couple hole 20 and the standard couple hole 19 in sequence to extend into the test positioning tube 5. The left end of the elongated positioning block 14 is inserted into the furnace tube 1. The device is equipped with an elongated positioning block 14, which increases the constraint length on the position of the test standard couple 6, reduces the deviation of the test standard couple 6 caused by the gap between the opening of the measuring end positioning block 4 and the test positioning tube 5, and does not cause additional large interference to the temperature field inside the furnace. Based on the height of the horizontal positioning block 13, the horizontal positioning block 13 is supported by the telescopic support mechanism. During adjustment, the adjusting ring 11 is loosened, and the height of the V-shaped bracket 12 is adjusted. After the position is determined, the adjusting ring 11 can be rotated. At this time, the V-shaped bracket 12 supports the horizontal positioning block 13, so that the central axis of the horizontal positioning block 13 and the long positioning block 14 coincides with the central axis of the furnace tube 1. The level bubble 22 is placed in the blind slot 21. The level bubble 22 provides a "ruler" for the test standard couple 6 to be parallel to the central axis of the furnace tube 1. This device reduces the uncertainty of the test results of the calibration furnace temperature field caused by the position deviation of the standard couple temperature measuring point, and can more accurately test, characterize, and evaluate the temperature field of the base metal thermocouple calibration furnace.

[0034] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An external positioning device for testing the temperature field of a base metal thermocouple calibration furnace, comprising a support base (7), connecting bolts (16), a horizontal positioning block (13), and a long positioning block (14), characterized in that: The horizontal positioning block (13) and the elongated positioning block (14) have the same outer diameter. The left end of the elongated positioning block (14) is inserted into the furnace tube (1) of the base metal thermocouple calibration furnace. The horizontal positioning block (13) is located above the support base (7). A telescopic support mechanism is provided between the support base (7) and the horizontal positioning block (13). The elongated positioning block (14) is located to the left of the horizontal positioning block (13). Two connecting through holes are provided on the elongated positioning block (14). The horizontal positioning block (13) has two connecting through holes (23), which are coaxially arranged. The right side end of the connecting bolt (16) passes through the connecting through hole (18) and the connecting through hole (23) and is connected with a nut. The left side end of the elongated positioning block (14) has two positioning tube holes (17), one of which is coaxially arranged with the elongated positioning block (14). The right end of the positioning block (14) has two standard pairs of holes (19), which are connected to two positioning tube holes (17). The inner diameter of the positioning tube hole (17) is larger than that of the standard pairs of holes (19). The horizontal positioning block (13) has two standard pairs of holes (20), which are coaxially arranged with the two standard pairs of holes (20). (20) The same size, the horizontal positioning block (13) has a blind hole (24) on the right end, and a horizontal bubble (22) is provided in the blind hole (24). The central axis of the blind hole (24) is parallel to the central axis of the horizontal positioning block (13). A positioning ring (15) is provided on the outer wall of the elongated positioning block (14). The positioning ring (15) is integrally formed with the elongated positioning block (14). The outer diameter of the positioning ring (15) is larger than the outer diameter of the elongated positioning block (14). The telescopic support mechanism includes a telescopic outer cylinder (8), a clamping plate (9), a telescopic adjusting rod (10), an adjusting ring (11), and a V-shaped bracket (12).

2. The external positioner for testing the temperature field of a base metal thermocouple calibration furnace according to claim 1, characterized in that: The horizontal positioning block (13) has several blind grooves (21) on its outer side wall. There are at least three blind grooves (21), and the central axis of the blind grooves (21) is parallel to the central axis of the horizontal positioning block (13).

3. The external positioner for temperature field testing of a base metal thermocouple calibration furnace according to claim 1, characterized in that: The telescopic outer cylinder (8) is fixed on the support base (7). Several clamping plates (9) are provided, and several clamping plates (9) are fixed on the upper end of the telescopic outer cylinder (8). The lower end of the telescopic adjustment rod (10) extends into the telescopic outer cylinder (8). The upper end of the telescopic adjustment rod (10) is fixedly connected to the lower end of the V-shaped bracket (12). The adjustment ring (11) is sleeved on the telescopic outer cylinder (8). Several clamping plates (9) are threadedly connected to the adjustment ring (11).

4. The external positioner for testing the temperature field of a base metal thermocouple calibration furnace according to claim 1, characterized in that: The elongated positioning block (14) is made of mullite, high-alumina brick or corundum; the horizontal positioning block (13) is made of transparent materials such as quartz glass or ordinary glass, or it can be made of metal iron, aluminum, copper, steel or corundum; the connecting bolt (16) is made of stainless steel or corundum; and the V-shaped bracket (12) is made of aluminum alloy or stainless steel.

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