CN209831112U - Temperature measuring cutter suitable for energetic material cutting processing - Google Patents

Abstract

The utility model discloses a be suitable for energetic material cutting process's temperature measurement cutter, including standard blade, diamond segments, thermoscope and DC power supply, diamond segments is installed at the knife tip position of standard blade, be equipped with thermal resistance and thermocouple on the diamond segments, thermoscope and DC power supply respectively with thermal resistance and thermocouple logical connection. The utility model discloses stand up present ripe machining process of energetic material, it can cooperate with present general processing equipment to use to have industry standard interface, need not to add additional danger source and introduce, can carry out accurate, quick measurement to energetic material cutting temperature under the special condition, very be favorable to PBX energetic material part processing safety technology research; meanwhile, the excellent cutting performance of the single crystal diamond cutter is also beneficial to improving the surface processing quality of the PBX composite material, and a new way is provided for realizing the safe, high-quality and high-efficiency processing technology development of the workpiece.

Description

Temperature measuring cutter suitable for energetic material cutting processing

Technical Field

The utility model relates to an energetic material machining technical field especially relates to the temperature measurement cutter who is suitable for energetic material cutting process.

Background

The high-energy explosive PBX (Polymer bound Explosives) is an energetic material with excellent comprehensive performance, is used as a core functional component material of various important warheads, and is widely applied to various weapon systems of land, sea, air and cannon. With the rapid development of weaponry systems, the demand for precision machining of various energetic material components is increasing, and machining safety has always been the key to limiting the technological development. In the process of cutting and processing energetic material workpieces, hard particles are randomly distributed in the energetic crystal bonded with PBX materials due to the non-uniformity of the grain size of the energetic crystal, when a certain hard particle is cut, or due to cutting deformation, vibration and the like, a large amount of cutting heat is suddenly generated to enable the workpieces to generate instantaneous high-temperature pulses, and when the instantaneous high temperature exceeds a certain range, the workpieces are detonated to cause serious malignant accidents. Therefore, the rapid and accurate measurement of the dynamic cutting temperature during the processing of the energetic material has great significance for the safe and efficient production of national defense and military departments. In addition, the material is a very special heterogeneous macroscopic isotropy microscopic anisotropy composite material due to low rigidity and strength, large thermal expansion coefficient and certain viscoelasticity, and the quality control of the precision machining of products is finished only by adopting a traditional cutter (high-speed steel, hard alloy and the like), so that certain difficulty is still caused. In view of this, aiming at the machining requirement of energetic materials, it would be very beneficial to develop a special tool system which can not only rapidly and accurately measure the cutting temperature, but also effectively improve the machining quality of products.

At present, the cutting temperature measurement methods widely adopted at home and abroad mainly include a natural thermocouple method, an artificial thermocouple method, a semi-artificial thermocouple method, a metallographic structure observation method, a photothermal radiation thermometry method and the like. For energetic material cutting, a common cutting temperature measuring method is limited by the response speed of a sensor, cutting conditions and the like, so that the real-time and accurate measurement of the transient temperature of a cutting area is difficult to realize. Aiming at the technical problem, researchers of the university of the general engineering work develop a NiCr/NiSi film thermocouple temperature measuring cutter by integrating a film thermocouple into a cutting cutter based on the magnetron sputtering technology, can realize the transient temperature measurement of a cutting area, but has high cost and complex technology. Researchers at PANTEX factory and Texas State university in 2018 complete dynamic temperature measurement of PBX9501 energetic materials by means of infrared thermographic temperature measurement and tool gradient integrated thermocouples, and the temperature measurement tools are complex in structural design and difficult to accurately represent temperature rise of cutting edge regions. Meanwhile, Chinese patent with publication number CN104942318B discloses an intelligent transient cutting temperature measurement cutter, a manufacturing method and a temperature measurement method, wherein a thin-film thermocouple is coated on the surface of the cutter, and an on-site temperature acquisition terminal is integrated for acquiring cutting temperature data in real time, but the temperature measurement accuracy is limited by a cutter base body, so that the highest cutting temperature is difficult to obtain; the Chinese patent with publication number CN105458312B discloses a micro-texture packaging temperature measuring cutter, which solves the problems that the existing temperature measuring cutter sensor is easy to wear, fall off and lose efficacy and reduce the cutting performance of the cutter; chinese patent publication No. CN106975984A discloses an intelligent transient milling temperature measurement tool based on a thin-film thermocouple, which realizes automatic acquisition, automatic processing, automatic storage and wireless transmission of temperature data by using an advanced transient temperature measurement method of the thin-film thermocouple and combining with a self-designed temperature acquisition module, is suitable for high-speed cutting, thin-walled workpieces and precision and ultra-precision machining, and has the advantages of high response speed, high measurement precision and the like, but the structure is complex, the cost is high, and the system reliability needs to be improved.

Therefore, the prior art and the report of the utility model still have the following defects for solving the problem of accurate temperature measurement in the machining of energetic materials: 1) the cutter contact type temperature measuring sensors have different integration forms and complex structures, and are difficult to accurately calibrate and repeatedly manufacture; 2) the response speed and the measurement precision of the integrated temperature measuring cutter are to be improved, and particularly the temperature rise area of the cutting edge part is accurately measured; 3) the blades of the integrated temperature measuring cutter have different quality and are difficult to measure and calculate quantitatively, and the integrated temperature measuring cutter is not designed for being suitable for processing quality control of energetic materials. The application problems of the improvement of energetic material machining equipment and novel technology exist, and the popularization difficulty of different degrees exists in the existing all-aspect limitation. Therefore, based on the existing mature processing technology of energetic materials, a set of safe, reliable, simple, practical, accurate-measurement and rapid-response temperature measurement cutter system is designed and researched, which is necessary to solve the practical problems in the production of the materials.

SUMMERY OF THE UTILITY MODEL

To foretell a great deal of problem, the utility model provides a be suitable for energetic material cutting process's temperature measurement cutter and test method can show and improve experiment temperature measurement condition and data accuracy, promotes PBX energetic material processing safety prevention and control test technical ability.

The utility model discloses a following technical scheme realizes above-mentioned purpose:

the temperature measuring cutter suitable for cutting and processing energetic materials comprises a standard blade, a diamond cutter head, a temperature measuring instrument and a direct-current power supply, wherein the diamond cutter head is installed at the cutter point of the standard blade, a thermal resistor and a thermocouple are arranged on the diamond cutter head, and the temperature measuring instrument and the direct-current power supply are respectively in logical connection with the thermal resistor and the thermocouple.

The diamond tool bit is formed by sharpening single crystal diamond, the sharpness of the cutting edge is less than 50nm, and the arc radius of the tool tip is more than 200 mu m.

The further scheme is that a thermal resistor is bonded at the cutting edge opening and the tool point of the diamond tool bit, one end pin of the thermal resistor is connected to a common grounding end C node of a thermodetector and a direct-current power supply through a lead, and the other end pin of the thermal resistor is reliably connected with a switch node D through a lead; a micro groove is formed in the front cutter face of the diamond cutter head, and thermocouples I are symmetrically packaged in the micro groove through sealant; thermocouple II and thermocouple III are adhered to the positions suitable for measurement on the front cutter face and the rear cutter face of the diamond cutter head; the thermocouples with different installation forms are logically connected with the anode and the cathode of the temperature measuring instrument through leads.

The further scheme is that the thermal resistor can be dismounted without damage and reused, the interchangeable error is +/-0.2 ℃, the working range is-80 ℃ to 150 ℃, and the connection mode is a two-wire system or a multi-wire system.

The thermometer is provided with at least 8 high-speed channels, and can simultaneously meet the sampling test requirements of a thermocouple I23, a thermocouple II, a thermocouple III and a thermal resistor; the direct current power supply can be integrated with a temperature measuring instrument for testing, the stable output current value can be infinitely adjusted, and is not less than 300 mA.

The further scheme is that a micro-groove for packaging the thermocouple I is formed in the front cutter face of the diamond cutter head, the micro-groove is prepared by an ultrafast laser processing method, the groove depth is 300 mu m, the groove width is 400 mu m, and the sealant is OMEGABOND adhesive.

The thermocouple I, the thermocouple II and the thermocouple III have millisecond-level response time and extremely low thermal inertia, the highest measurement temperature is higher than 300 ℃, the measurement error is less than +/-0.5 ℃, the thickness of a foil is about 0.013mm, and the diameter of a lead is less than 0.25 mm.

Need mark it before using, the utility model discloses another aspect provides foretell be suitable for the accurate temperature measurement cutter's of energetic material cutting process calibration method, and the calibration step is as follows: a, finishing temperature measurement cutter manufacturing and test circuit connection according to design requirements, wherein each temperature measurement device is accurately calibrated; b, starting the temperature measuring instrument and the direct-current power supply under the test condition, closing the single-knife switch nodes A and D after the heat engine is stable, and communicating the single-knife switch nodes A and D with the direct-current power supply to realize instant heating and temperature rise of the thermal resistor and ensure that all temperature measuring devices work effectively; c, rapidly closing the single-knife switch nodes B and D several seconds after a period of time, disconnecting the direct-current power supply and simultaneously connecting the temperature measuring instrument, and realizing accurate transient temperature measurement of the thermal resistor, the thermocouple I, the thermocouple II and the thermocouple III; d, continuously and synchronously recording real-time temperature measurement data of the thermal resistor and the thermocouples I, II and III by using a temperature measuring instrument; e, repeating the steps for multiple times, completing the calibration of different cutting edge temperatures of the temperature measuring cutter, associating the test data of the thermocouple I, the thermocouple II and the thermocouple III, and disconnecting a system circuit.

The utility model discloses another aspect provides foretell be suitable for energetic material cutting process's accurate temperature measurement cutter's test method, a serial communication port, accurate temperature measurement cutter test step is as follows: a, demolishing a thermal resistor at the tool tip of the diamond tool bit without damage, and finishing the cutting edge cleaning and circuit inspection of the calibrated temperature measurement tool; b, reliably connecting a thermocouple I, a thermocouple II and a thermocouple III on the diamond tool bit with a temperature measuring instrument according to the actual machining working condition, and arranging a standard blade mounting device on a cutting machine tool; and c, starting a thermodetector according to the experimental requirements, and carrying out accurate real-time cutting temperature monitoring and recording.

The beneficial effects of the utility model reside in that:

(1) the utility model provides a simple and easy, portable temperature measurement cutter and method are suitable for accurate, the quick measurement of cutter blade temperature rise in the energetic material cutting process, provide reliable data support for the research of energetic material cutting thermal response mechanism, have the apparent characteristic that promotes energetic material machining essence safety level and this type of product surface machining quality. The utility model discloses a have simple structure, the response is rapid, and it is accurate to measure, convenient to use, low cost, easy and all kinds of lathe integrated use and technological expansibility advantage such as strong.

(2) The utility model utilizes the Joule electrothermal effect and the Seebeck thermoelectric temperature measurement principle to synchronously realize the self-heating and temperature measurement functions of the thermal resistor by means of logic circuit control; through reasonable structural design and space separation (calibration and use) of a temperature measurement mode, a single crystal diamond cutter with excellent heat conductivity and a foil thermocouple are integrally designed and uniformly calibrated, and then the mapping relation between the temperature rise of the cutting edge of the cutter and a temperature measurement sensor is established, so that millisecond-level response and online accurate temperature measurement at the cutting edge of the cutting cutter can be realized.

(3) The utility model discloses stand up present ripe machining process of energetic material, it can use with present general processing equipment to have the industry standard interface, need not plus dangerous source (heat, electricity, power source) to introduce, can carry out accurate, quick measurement to energetic material cutting temperature under the special condition, very be favorable to PBX energetic material parts machining safety technical research; meanwhile, the excellent cutting performance of the single crystal diamond cutter is also beneficial to improving the surface processing quality of the PBX composite material, and a new way is provided for realizing the safe, high-quality and high-efficiency processing technology development of the workpiece.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the embodiments or the drawings needed in the prior art description, and obviously, the drawings in the following description are only some embodiments of the embodiments, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic diagram of the general structure and calibration method of the accurate temperature measuring tool suitable for cutting energetic materials.

FIG. 2 is an isometric view and a partially enlarged view of a tool tip suitable for machining energetic materials with accurate temperature measurement, showing the state of the tool tip during calibration.

Fig. 3 is an isometric view and a partially enlarged view of a tool tip suitable for accurate thermometric cutting of energetic materials according to the present invention, showing the state of the tool tip during cutting.

As shown, in which corresponding reference characters designate:

1 standard blade, 2 diamond tool bits, 21 thermal resistors, 22 sealant, 23 thermocouples I, 24 thermocouples II, 25 thermocouples III, 3 thermometers and 4 direct-current power supplies.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

As shown in FIGS. 1-3, the utility model discloses a be suitable for temperature measurement cutter of energetic material cutting process, including standard blade 1, diamond segments 2, thermoscope 3 and DC power supply 4, diamond segments 2 are installed at the knife tip position of standard blade 1, be equipped with thermal resistance and thermocouple on the diamond segments 2, thermoscope 3 and DC power supply 4 respectively with thermal resistance and thermocouple logical connection.

In the embodiment, the diamond tool bit 2 is formed by sharpening single crystal diamond, the sharpness of the cutting edge is less than 50nm, and the arc radius of the tool tip is more than 200 microns.

In the embodiment, a thermal resistor 21 is bonded at the cutting edge tip of the cutting edge of the diamond tool bit 2, one end pin of the thermal resistor 21 is connected to a common grounding terminal node C of the temperature measuring instrument 3 and the direct-current power supply 4 through a wire, and the other end pin of the thermal resistor 21 is reliably connected with a switch node D through a wire; a micro groove is formed in the front cutter face of the diamond cutter head 2, and thermocouples I23 are symmetrically packaged in the micro groove through a sealant 22; thermocouple II 24 and thermocouple III 25 are adhered to the positions suitable for measurement on the front cutter face and the rear cutter face of the diamond cutter head 2; the thermocouples with different installation forms are logically connected with the anode and the cathode of the temperature measuring instrument through leads.

In this embodiment, the thermal resistor 21 can be removed and reused without damage, the interchangeable error is ± 0.2 ℃, the working range is-80 ℃ to 150 ℃, and the connection mode is a two-wire system or a multi-wire system.

In this embodiment, the temperature measuring instrument 3 has at least 8 high-speed channels, and can simultaneously meet the sampling test requirements of the thermocouple i 23, the thermocouple ii 24, the thermocouple iii 25 and the thermal resistor 21; the direct current power supply 4 can be integrated with the temperature measuring instrument 3 for testing, and the stable output current value can be infinitely adjusted and is not less than 300 mA.

In the embodiment, the micro-groove for packaging the thermocouple I23 is formed in the front tool face of the diamond tool bit 2 and is prepared by an ultrafast laser processing method, the groove depth is 300 microns, the groove width is 400 microns, and the sealant 22 is an OMEGABOND adhesive.

In the embodiment, the thermocouple I23, the thermocouple II 24 and the thermocouple III 25 have millisecond-level response time and extremely low thermal inertia, the highest measurement temperature is more than 300 ℃, the measurement error is less than +/-0.5 ℃, the thickness of a foil is about 0.013mm, and the diameter of a lead is less than 0.25 mm.

Specifically, the utility model discloses based on joule electrothermal effect and seebeck thermoelectric temperature measurement principle, carry out integrated design and unified calibration with the good single crystal diamond cutter of heat conductivity and foil thermocouple, disclose an accurate temperature measurement cutter that is suitable for energetic material cutting process, it includes standard blade, diamond segments, thermoscope and DC power supply. The standard blade substrate meets the industrial design standard, is provided with a universal pressing positioning hole and can be freely assembled on an energetic material processing machine tool, the used material is generally hard alloy, and a diamond tool bit can be installed at the tool tip part of the standard blade substrate by utilizing a special welding process; temperature measuring and heating sensors are arranged at specific positions inside and on the surface of the diamond cutter head, the temperature measuring instrument and the direct-current power supply are respectively in logic connection with the testing sensors, the self-heating and temperature measuring function conversion of the thermal resistor of the cutting edge of the cutter is utilized, and the foil thermocouple integrated on the diamond cutter head is matched for temperature measurement, so that the overall accurate calibration and temperature measuring functions of the cutter are realized.

In order to ensure the utility model's operational performance and system reliability, carry out the preferred design to its key function device and important design parameter, as shown in fig. 1 and fig. 2, the preferred embodiment in this embodiment is, the diamond tool bit is formed by the accurate sharpening of single crystal diamond, preferably natural single crystal material, its blade sharpness is less than 50nm, knife tip circular arc radius is greater than 200 μm, have the uniformity of high thermal conductivity (k 1000W/m/° c), can accurately measure and calculate its heat transfer law through theory and simulation, can regard it as the part of waiting to mark of temperature measurement thermocouple sensor in this embodiment; a thermal resistor is bonded at the position of a cutting edge opening and a tool tip of the diamond tool bit, one end pin of the thermal resistor is connected to a common grounding end C node of the thermodetector and the direct-current power supply through a wire, and the other end pin of the thermal resistor is reliably connected with a switch node D through a wire, so that the convenient switching of resistance heating and rapid temperature measurement functions can be realized. A microgroove is formed in a specific position on the front cutter face of the diamond cutter head, and the thermocouple I is symmetrically packaged into the microgroove by adopting special sealant; thermocouple II and thermocouple III are adhered to specific positions suitable for measurement on the front cutter face or the rear cutter face of the diamond cutter head, and the thermocouples in different installation forms are correspondingly connected with the anode and the cathode of the temperature measuring instrument through leads; in the embodiment, only a typical installation mode of the thermocouple is shown, and adjustment can be performed according to different cutting conditions, such as introduction of an electric slip ring after a blade thermocouple is pasted in drilling and milling; the thermal resistor can be dismounted without damage and reused, the interchangeable error is +/-0.2 ℃, and the working range is as follows: the connection mode can be two-wire system or multi-wire system according to the requirement of test precision, the measurement error caused by the resistance of the connecting lead can be effectively eliminated by adopting the multi-wire system connection method, and the used mounting adhesive has good thermal conductivity and thermosetting property; the thermodetector is provided with at least 8 high-speed channels, and can simultaneously meet the sampling test requirements of a selected thermocouple and a selected thermal resistor; the direct current power supply can be integrated with a temperature measuring instrument for testing, the structure is portable, the stable output current value can be infinitely adjusted and is not less than 300 mA; the microstructure or the microgroove for packaging the thermocouple I arranged on the front cutter face of the diamond cutter head can be prepared by adopting an ultrafast (fs or ps) laser processing method, the groove depth is preferably 300 mu m, the groove width is preferably 400 mu m, the sealant has good heat conductivity and thermosetting property, and an OMEGABOND brand special adhesive is generally selected; the thermocouple position selection principle is characterized in that a thermocouple position selection principle is installed on the front cutter face or the rear cutter face of the diamond cutter head: the use of the cutter is not influenced, the measurement and the arrangement are convenient, and the temperature measurement node is as close to the cutter point as possible; the thermocouple should have millisecond response time and extremely low thermal inertia, with a maximum measurement temperature of greater than 300 ℃, a measurement error of less than plus or minus 0.5 ℃, a foil thickness of about 0.013mm, a wire diameter of less than 0.25mm, preferably an OMEGA brand adhesive foil thermocouple; and finally, the overall calibration (thermocouple and diamond) of the diamond tool bit in the temperature measuring tool is completed, and the establishment of the temperature mapping relation between the thermocouple and the diamond cutting edge is realized.

As shown in figures 1 and 3, the utility model provides a test method of the accurate temperature measurement cutter of energetic material cutting process, which can be divided into two parts of calibration and cutting process test before the cutter is used. The calibration implementation steps are as follows: (a) manufacturing a temperature measuring cutter and testing circuit connection are completed according to design requirements, and each temperature measuring device is accurately calibrated; (b) under the test condition, starting the temperature measuring instrument and the direct-current power supply, closing the single-knife switch nodes A and D after the heat engine is stable, communicating the direct-current power supply, realizing instant heating and temperature rise of the thermal resistor, and ensuring that all temperature measuring devices work effectively; (c) after a period of time (several seconds), rapidly closing the single-pole switch nodes B and D, disconnecting the direct-current power supply and simultaneously connecting the temperature measuring instrument, and realizing accurate transient temperature measurement of the thermal resistor and the thermocouple; continuously and synchronously recording real-time temperature measurement data of the thermal resistor and the thermocouple by adopting a temperature measuring instrument; (e) and repeating the steps for multiple times to finish the calibration of different cutting edge temperatures of the temperature measuring cutter, associating the test data of each thermocouple and disconnecting a system circuit. As shown in fig. 3, the temperature measurement of the cutting experiment can be performed after the calibration of the precise temperature measurement tool is completed, and the testing steps of the precise temperature measurement tool are as follows: (a) the thermal resistor at the tool point of the diamond tool bit is removed without damage, and the cutting edge cleaning and the circuit inspection of the calibrated temperature measurement tool are completed; (b) according to the actual processing working condition, reliably connecting a thermocouple on the diamond tool bit with a temperature measuring instrument, and arranging a standard blade on a cutting machine tool; (c) and (4) starting a thermodetector according to experimental requirements, and carrying out accurate and dynamic cutting temperature monitoring and real-time recording.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims. It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and in order to avoid unnecessary repetition, the present invention does not need to describe any combination of the features. In addition, various embodiments of the present invention can be combined arbitrarily, and the disclosed content should be regarded as the present invention as long as it does not violate the idea of the present invention.

Claims (7)

1. Be suitable for temperature measurement cutter of energetic material cutting process, including standard blade (1), diamond segments (2), thermoscope (3) and DC power supply (4), its characterized in that: the diamond tool bit (2) is installed at the tool tip of the standard blade (1), the thermal resistor and the thermocouple are arranged on the diamond tool bit (2), and the thermodetector (3) and the direct-current power supply (4) are respectively in logical connection with the thermal resistor and the thermocouple.

2. The thermometric tool according to claim 1, wherein said diamond tip (2) is sharpened by single crystal diamond, the sharpness of the edge is less than 50nm, and the radius of the circular arc of the tip is more than 200 μm.

3. The temperature measuring cutter suitable for cutting energetic materials according to any one of claims 1-2, wherein a thermal resistor (21) is bonded at the cutting edge opening tip of the diamond cutter head (2), one end pin of the thermal resistor (21) is connected to a common grounding terminal C node of the temperature measuring instrument (3) and the direct current power supply (4) through a lead, and the other end pin is reliably connected with a switch node D through a lead; a micro groove is formed in the front cutter face of the diamond cutter head (2), and thermocouples I (23) are symmetrically packaged in the micro groove through a sealant (22); thermocouple II (24) and thermocouple III (25) are adhered to the front cutter face and the rear cutter face of the diamond cutter head (2) at positions suitable for measurement; the thermocouples with different installation forms are logically connected with the anode and the cathode of the temperature measuring instrument through leads.

4. Temperature measuring tool suitable for energetic material cutting according to claim 3, characterized by the fact that the thermal resistance (21) can be removed and reused without losses, with an interchangeable tolerance of ± 0.2 ℃, with a working range of-80 ℃ to 150 ℃, in a two-wire or multi-wire connection.

5. The temperature measuring tool suitable for cutting energetic materials as claimed in claim 3, wherein the temperature measuring instrument (3) has at least 8 high speed channels, and can simultaneously meet the sampling test requirements of a thermocouple I (23), a thermocouple II (24), a thermocouple III (25) and a thermal resistor (21); the direct current power supply (4) can be integrated with the temperature measuring instrument (3) for testing, the stable output current value can be stepless adjustable, and is not less than 300 mA.

6. The temperature measuring tool suitable for cutting energetic materials as claimed in claim 3, wherein the micro-groove for packaging thermocouple I (23) formed on the front face of the diamond tool bit (2) is prepared by ultra-fast laser processing, the groove depth is 300 μm, the groove width is 400 μm, and the sealant (22) is OMEGABOND adhesive.

7. The thermometric tool according to claim 3, wherein said thermocouple I (23), thermocouple II (24), and thermocouple III (25) have millisecond response times and extremely low thermal inertia, with a maximum measured temperature greater than 300 ℃, a measurement error less than ± 0.5 ℃, and a wire diameter less than 0.25 mm.