Thermocouple indication error period checking device and method

Abstract

The invention discloses a thermocouple indication error period checking device and method. The device comprises a heating mechanism, a 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 thermocouple checking mechanism. The method comprises the following steps: 1, placing a solid standard sample and installing a thermocouple; 2, manufacturing a standard temperature source; and 3, checking the indication error of the thermocouple to be checked. The temperature control thermocouple and the thermocouple to be checked are placed in the crucible at the same time, the heating furnace is used for providing a heat source for the crucible, solid metal in the crucible is melted to serve as a temperature source of the temperature control thermocouple and the thermocouple to be checked, and the indicating value error of the thermocouple to be checked is checked through the standard metal sample. The method is not limited by traditional thermocouple checking regions and laboratories, and regular traceability is not needed; the melting point of the standard metal sample is used as a temperature standard value, and a stable standard temperature is provided for the indication error of the thermocouple to be checked.

Description

Technical Field

[0001] The invention belongs to the technical field of thermocouple period verification, and in particular relates to a device and method for period verification of thermocouple indication error. Background Art

[0002] At present, the verification method of thermocouple indication error can be based on JJF1637-2017 cheap metal thermocouple calibration specification, JJF1262-2010 armored thermocouple calibration specification and JJG141-2013 working precious metal thermocouple verification procedure, etc. These methods all require the thermocouple calibration furnace to be heated to the calibration temperature point, and the indication error is verified after the temperature stabilizes. Thermocouple verification takes 6-8 hours, and the verification efficiency is low. In addition, traditional thermocouple calibration has regional and laboratory restrictions and cannot meet the verification needs of online and on-site thermocouple indication errors. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a device for checking the indication error of a thermocouple in view of the deficiencies in the above-mentioned prior art. A temperature-controlling thermocouple and a thermocouple to be checked are placed in a crucible at the same time, and a heating furnace is used to provide a heat source for the crucible to melt the solid metal in the crucible, which serves as a temperature source for the temperature-controlling thermocouple and the thermocouple to be checked. A standard metal sample is used to check the indication error of the thermocouple to be checked, which is not restricted by the traditional thermocouple verification region and laboratory, and does not require regular tracing. The melting point of the standard metal sample is used as the temperature standard value to provide a stable standard temperature for the indication error of the thermocouple to be checked. Compared with the traditional tubular furnace, liquid metal is more stable and safer as a standard temperature source.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a device for checking the error of thermocouple indication, characterized in that it comprises a heating mechanism, a 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 thermocouple checking mechanism;

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

[0006] The thermocouple checking mechanism comprises a plurality of thermocouple sleeves to be checked and a temperature-controlling sleeve, all of which are vertically arranged, the bottoms of the thermocouple sleeves to be checked and the temperature-controlling sleeve are both flush with the bottom of the crucible, and the tops of the thermocouple sleeves to be checked and the temperature-controlling sleeve pass through the top of the sealing cover and extend to above the sealing cover;

[0007] The thermocouple fixing frame comprises a fixing frame body arranged at one side of the crucible, 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 arranged on the adjustable fixing seat.

[0008] The above-mentioned device for checking the error of thermocouple indication is characterized in that: a funnel socket is also opened on one side of the sealing cover, and a sealing plug is arranged on the funnel socket; the depth of the funnel socket is equal to the height of the sealing cover, and the funnel socket is connected to the inside of the crucible.

[0009] The above-mentioned device for checking the error of thermocouple indication is characterized in that the thermocouple sleeve to be checked and the temperature control sleeve are both connected to the sealing cover by fastening bolts, and the fastening bolts are fixed on the top of the sealing cover.

[0010] The above-mentioned device for checking the error of thermocouple indication is characterized in that: the inner diameter of the thermocouple sleeve to be checked is larger than the diameter of the thermocouple to be checked; the inner diameter of the temperature-controlling thermocouple sleeve is larger than the diameter of the temperature-controlling thermocouple.

[0011] The above-mentioned device for checking the error of thermocouple indication is characterized in that the thermocouple sleeve to be checked and the temperature control thermocouple sleeve are both high-temperature ceramic sleeves.

[0012] The above-mentioned device for checking the error of thermocouple indication 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.

[0013] The above-mentioned device for checking the error of thermocouple indication is characterized in that: the adjustable fixing seat includes an adjustable fixing plate arranged on a fixing bracket, a positioning screw arranged on one side of the adjustable fixing plate and used to fix the position of the adjustable fixing plate, and a connecting frame arranged on the other side of the adjustable fixing plate and used to fix the thermocouple, the connecting frame and the fixing clamp are connected by a fastening screw; the fixing clamp is connected to the fastening screw through a horizontal fixing rod.

[0014] The above-mentioned device for checking the error of thermocouple indication is characterized in that: the temperature-controlling thermocouple in the temperature-controlling thermocouple sleeve is connected to the temperature-controlling instrument; and the thermocouple to be checked in the thermocouple sleeve to be checked is connected to a high-precision data collector.

[0015] The present invention also provides a method for period checking of thermocouple indication error by a period checking device for thermocouple indication error, characterized in that the method comprises the following steps:

[0016] Step 1, placing a solid standard sample and installing a thermocouple: placing a solid standard sample with a mass of m grams into a crucible, placing a temperature-controlled thermocouple into a temperature-controlled thermocouple sleeve and fixing it with a thermocouple fixing frame, and placing a thermocouple to be checked into a thermocouple sleeve to be checked and fixing it with a thermocouple fixing frame; the temperature-controlled thermocouple and the thermocouple to be checked are both inserted into the crucible to a depth of h, and the calculation formula of h is h=H-h1 / 2, wherein H is the depth of the crucible; h1 is the depth of the solid standard sample to become a liquid standard sample after heating;

[0017] Step 2, making a standard temperature source: using asbestos to seal the pipe openings of the thermocouple sleeve to be checked and the temperature-controlling thermocouple sleeve, and then starting the heating furnace to heat the crucible; 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 has been completely melted; opening the sealing plug, inserting the funnel to re-add the solid standard sample to the crucible, so that the standard sample in the crucible maintains the form of solid-liquid coexistence, at this time the temperature of the standard sample is constant at the melting point temperature, and the solid-liquid coexistence standard sample in the crucible is used as the standard temperature source;

[0018] Step 3: Check the indication error of the thermocouple to be checked. The process is as follows:

[0019] Step 301: Use a high-precision data collector to collect data on the 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 thermocouple to be checked. The indication error of the thermocouple to be checked is Δt=tt b ; where t b is the melting point temperature of the standard sample;

[0020] Step 302: Continue to use the high-precision data collector to collect data on the 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 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.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The present invention puts a temperature-controlling thermocouple and a thermocouple to be checked into a crucible at the same time, uses a heating furnace to provide a heat source for the crucible, melts the solid metal in the crucible, and uses the metal as the temperature source for the temperature-controlling thermocouple and the thermocouple to be checked. A standard metal sample is used to check the indication error of the thermocouple to be checked. The invention is not restricted by the traditional thermocouple checking region and laboratory, does not require regular traceability, has a simple structure, and is easy to use.

[0023] 2. The present invention uses the melting point of the standard metal sample as the temperature standard value to provide a stable standard temperature for the indication error of the thermocouple to be verified. Compared with the traditional tube furnace, liquid metal is more stable and safer as a standard temperature source; at the same time, it is not restricted by the traditional thermocouple verification area and laboratory, does not require regular traceability and interim verification, and can achieve online and on-site traceability to meet the industry's metrology and testing needs.

[0024] 3. The present invention does not require a thermostat to maintain temperature during the traditional indication error verification process. It only needs to install the thermocouple to be verified in the high-temperature ceramic furnace, and start collecting data when the temperature of the thermocouple to be controlled remains unchanged. The operation is simple.

[0025] In summary, the present invention places a temperature-controlling thermocouple and a thermocouple to be checked into a crucible at the same time, uses a heating furnace to provide a heat source for the crucible, melts the solid metal in the crucible, and uses the metal as a temperature source for the temperature-controlling thermocouple and the thermocouple to be checked. A standard metal sample is used to check the indication error of the thermocouple to be checked, which is not restricted by the traditional thermocouple verification region and laboratory, and does not require regular tracing. The melting point of the standard metal sample is used as the temperature standard value to provide a stable standard temperature for the indication error of the thermocouple to be checked. Compared with the traditional tubular furnace, liquid metal is more stable and safer as a standard temperature source.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the positional relationship between the heating mechanism and the thermocouple verification mechanism of the present invention.

[0028] Figure 2 It is a structural schematic diagram of the thermocouple fixing bracket of the present invention.

[0029] Figure 3 It is a schematic diagram of the connection relationship between the fixing clamp and the horizontal fixing rod of the present invention.

[0030] Figure 4 The figure is a flowchart of the method of the present invention.

[0031] Description of reference numerals:

[0032] 1—heating furnace; 2—crucible; 3—sealing cover;

[0033] 4—temperature control couple sleeve; 5—thermocouple sleeve to be checked; 6—fastening bolts;

[0034] 8—sealing plug; 9—adjustable fixing plate; 10—fixing clip;

[0035] 16—fixed bracket; 17—positioning screw; 18—connecting frame;

[0036] 19—fastening screw; 20—fixing base; 21—horizontal fixing rod. DETAILED DESCRIPTION

[0037] like Figures 1 to 3 A thermocouple indication error period checking device shown includes a heating mechanism, a thermocouple checking mechanism disposed in the heating mechanism, and a thermocouple fixing frame disposed on one side of the heating mechanism and matched with the thermocouple checking mechanism;

[0038] 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;

[0039] The thermocouple checking mechanism comprises a plurality of thermocouple sleeves 5 to be checked and a temperature-controlling sleeve 4, all of which are vertically arranged. The bottoms of the thermocouple sleeves 5 to be checked and the temperature-controlling sleeve 4 are both flush with the bottom of the crucible 2, and the tops of the thermocouple sleeves 5 to be checked and the temperature-controlling sleeve 4 pass through the top of the sealing cover 3 and extend to the top of the sealing cover 3.

[0040] The thermocouple fixing frame includes a fixing frame body arranged at 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.

[0041] The present invention places a temperature-controlling thermocouple and a thermocouple to be checked into a crucible 2 at the same time, uses a heating furnace 1 to provide a heat source for the crucible 2, melts the solid metal in the crucible 2, and uses the metal as a temperature source for the temperature-controlling thermocouple and the thermocouple to be checked. A standard metal sample is used to check the indication error of the thermocouple to be checked. The invention is not restricted by the traditional thermocouple checking region and laboratory, does not require regular traceability, has a simple structure, and is easy to use.

[0042] 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 metal liquid; the sealing cover 3 is a special sealing cover, which is easy to disassemble; the temperature-controlling thermocouple sleeve 4 is used to insert a temperature-controlling thermocouple, and the temperature-controlling thermocouple is connected with a temperature-controlling instrument to form a temperature-controlling device, which is used to monitor the temperature of the metal liquid; the thermocouple sleeve 5 to be checked is used to insert the thermocouple to be checked.

[0043] like Figure 1As shown, in this embodiment, a funnel socket is further 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 .

[0044] In actual use, the funnel socket is used to insert the funnel. When no solid metal is needed, the sealing plug 8 is covered. 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 metal liquid along the funnel. The funnel is a high-temperature resistant ceramic funnel for adding metal particles.

[0045] like Figure 1 As shown, in this embodiment, the to-be-inspected thermocouple sleeve 5 and the temperature-controlling thermocouple sleeve 4 are both connected to the sealing cover 3 via fastening bolts 6 , and the fastening bolts 6 are fixed on the top of the sealing cover 3 .

[0046] In this embodiment, the inner diameter of the to-be-checked thermocouple sleeve 5 is larger than the diameter of the to-be-checked thermocouple; the inner diameter of the temperature-controlling thermocouple sleeve 4 is larger than the diameter of the temperature-controlling thermocouple.

[0047] In this embodiment, the to-be-inspected thermocouple sleeve 5 and the temperature-controlling thermocouple sleeve 4 are both high-temperature ceramic sleeves.

[0048] like Figure 2 As shown, in this embodiment, the fixed frame body 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.

[0049] like Figure 2 As shown, in this embodiment, the adjustable fixing seat includes 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, and 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 through a horizontal fixing rod 21.

[0050] In actual use, the fixing frame is used to support and position the thermocouple; the fixing clamp 10 is used to clamp the thermocouple; and a lock is provided on the fixing clamp 10 to lock the fixing clamp 10 to fix the position of the thermocouple. Figure 2As shown, the side of the connecting frame 18 close to the adjustable fixing plate 9 is a conical structure, which is combined with the fastening screw 19 to position the horizontal direction of the horizontal fixing rod 21; the adjustable fixing plate 9 is a U-shaped structure, and the positioning screw 17 passes through a vertical section of the adjustable fixing plate 9 and the fixing bracket 16 in sequence and then passes through the other vertical section, and the positioning screw 17 and the adjustable fixing plate 9 are threadedly connected; the fixing bracket 16 is provided with 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 adjustable fixing seat as a whole. After the height is determined, the height is fixed by the threaded connection between the positioning screw 17 and the adjustable fixing plate 9.

[0051] In this embodiment, the temperature-controlling thermocouple in the temperature-controlling thermocouple sleeve 4 is connected to a temperature-controlling instrument; and the thermocouple to be checked in the thermocouple sleeve 5 to be checked is connected to a high-precision data collector.

[0052] like Figures 1 to 4 A method for performing period verification of a thermocouple indication error by a period verification device is shown, and the method comprises the following steps:

[0053] Step 1, placing a solid standard sample and installing a thermocouple: placing a solid standard sample with a mass of m grams into the crucible 2, placing a temperature-controlled thermocouple into the temperature-controlled thermocouple sleeve 4 and fixing it with a thermocouple fixing frame, and placing a thermocouple to be checked into the thermocouple sleeve 5 to be checked and fixing it with a thermocouple fixing frame; the temperature-controlled thermocouple and the 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 of the solid standard sample to become a liquid standard sample after being heated;

[0054] Step 2, making a standard temperature source: using asbestos to seal the pipe openings of the thermocouple sleeve 5 to be checked and the temperature control thermocouple sleeve 4, and then starting the heating furnace 1 to heat the crucible 2; observing the temperature reading on the temperature control instrument connected to the temperature control 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 re-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-liquid coexistence standard sample in the crucible 2 is used as the standard temperature source;

[0055] Step 3: Check the indication error of the thermocouple to be checked. The process is as follows:

[0056] Step 301: Use a high-precision data collector to collect data on the 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 thermocouple to be checked. The indication error of the thermocouple to be checked is Δt=tt b ; where t b is the melting point temperature of the standard sample;

[0057] Step 302: Continue to use the high-precision data collector to collect data on the 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 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.

[0058] The present invention uses the melting point of a standard metal sample as the temperature standard value to provide a stable standard temperature for the indication error of the thermocouple to be verified. Compared with the traditional tube furnace, liquid metal is more stable and safer as a standard temperature source. At the same time, it is not restricted by the traditional thermocouple verification area and laboratory, does not require regular traceability or interim verification, and can achieve online and on-site traceability to meet the needs of industrial metrology and testing.

[0059] The present invention does not require a thermostat for maintaining temperature during the traditional indication error verification process. It only requires installing the thermocouple to be verified in the high-temperature ceramic furnace and starting to collect data when the temperature of the thermocouple to be controlled remains unchanged. The operation is simple.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A device for checking the error of thermocouple indication during the period, characterized in that: It includes a heating mechanism, a 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 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 thermocouple checking mechanism comprises a plurality of thermocouple sleeves (5) to be checked and a temperature-controlling sleeve (4) which are arranged vertically, the bottoms of the thermocouple sleeves (5) to be checked and the temperature-controlling sleeve (4) are flush with the bottom of the crucible (2), and the tops of the thermocouple sleeves (5) to be checked and the temperature-controlling sleeve (4) pass through the top of the sealing cover (3) and extend to the top of the sealing cover (3); 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. A thermocouple indication error period checking device 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. A thermocouple indication error period checking device according to claim 1, characterized in that: The thermocouple sleeve (5) to be checked and the temperature-controlling thermocouple sleeve (4) are both connected to the sealing cover (3) via fastening bolts (6), and the fastening bolts (6) are fixed on the top of the sealing cover (3).

4. A thermocouple indication error period checking device according to claim 1, 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.

5. A thermocouple indication error period checking device according to claim 1, characterized in that: The thermocouple sleeve (5) to be checked and the temperature control thermocouple sleeve (4) are both high-temperature ceramic sleeves.

6. A thermocouple indication error period checking device according to claim 1, 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.

7. A thermocouple indication error period checking device according to claim 5, 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).

8. A thermocouple indication error period checking device according to claim 1, characterized in that: The temperature-controlling thermocouple in the temperature-controlling thermocouple sleeve (4) is connected to a temperature-controlling instrument; and the thermocouple to be checked in the thermocouple sleeve (5) to be checked is connected to a high-precision data collector.

9. The method for period checking of thermocouple indication error by a period checking device for thermocouple indication error according to claim 7, characterized in that: The method comprises the following steps: Step 1, 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 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 thermocouple to be checked are both inserted into the crucible (2) to a depth of h, and the calculation formula of h is h=Hh 1 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 2, 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, and 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 into the crucible (2), so that the standard sample in the crucible (2) maintains the form of solid and liquid coexistence, and at this time the temperature of the standard sample is constant at the melting point temperature, and the solid-liquid coexistence standard sample in the crucible (2) is used as the standard temperature source; Step 3: Check the indication error of the thermocouple to be checked. The process is as follows: Step 301: Use a high-precision data collector to collect data on the 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 thermocouple to be checked. The indication error of the thermocouple to be checked is Δt=tt b ; where t b is the melting point temperature of the standard sample; Step 302: Continue to use the high-precision data collector to collect data on the 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 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.

Images