Method and apparatus for determining temperature using thermocouple

Abstract

The invention relates to a method for determining the temperature of a cold junction of a thermocouple, to a method for determining the temperature of a high-temperature environment, to a thermocouple system and to a thermocouple device suitable for carrying out the method according to the invention.

Description

[0001] This invention relates to a method for determining the temperature of the cold junction of a thermocouple, a method for determining the temperature of a high-temperature environment, a thermocouple system and thermocouple device suitable for carrying out the method of the invention.

[0002] Especially during metal manufacturing processes employed in the steel industry, several parameters of the molten metal are critical for controlling the metallurgical process, such as the molten pool chemistry or temperature. For both economic and quality reasons, the ability to continuously and / or periodically monitor these variables is highly desirable. Accurate monitoring can significantly reduce energy consumption due to overheating and material consumption due to overprocessing. Methods and apparatus for determining these process-related parameters are known in the art, primarily involving the use of disposable probes that carry sensors. Typically, the probe is brought below the surface of the melt either as a drop-in sensor or via a spray gun assembly.

[0003] In industrial applications, thermocouples are frequently used as temperature sensors, especially when high temperatures need to be measured. A thermocouple consists of two conductors of different materials connected at a junction called the "hot" junction. Due to the Seebeck effect, a voltage is generated across the free end of the conductors when a temperature gradient exists between the free end and the hot junction. This voltage depends on the thermocouple's material composition and the temperature difference between the free end (also called the cold junction) and the hot junction. Therefore, given the temperature at the cold junction and the temperature characteristics of the system, the voltage can be used to determine the temperature at the hot junction. Different material combinations are typically known and standardized depending on the temperature to be measured, such as Type S thermocouples (Pt / PtRh10), Type R thermocouples (Pt / PtRh13), or Type C thermocouples (WRe5 / WRe26).

[0004] A thermocouple system typically includes several components: the thermocouple itself, wires or cables, processing instruments suitable for receiving and processing signals from the thermocouple circuit, and at least one sensor for measuring the temperature of a reference point (usually a cold junction).

[0005] The conductors used to bridge the distance between the actual thermocouple and the remotely positioned measuring instrument can be divided into three groups. The first type of conductor is the extension conductor, which is made of the same material as the conductor of the thermocouple itself. In many applications, the conductor of the thermocouple is made of precious metals such as platinum or platinum alloys, making the sensor and the matching extension conductor expensive. To reduce the use of these expensive materials, compensating conductors are widely used to limit the cost of the system. Compensating conductors are made of materials with approximately the same thermoelectric properties as the thermocouple conductors they are used with, i.e., producing the same thermoelectric voltage as the corresponding thermocouple at temperatures below 200°C. Such compensating conductors allow for an acceptable trade-off between cost and performance if the operating temperature of the compensating conductor remains within a certain range. For example, for a type S thermocouple consisting of a combination of pure Pt conductors and Pt10Rh conductors, the compensating conductors to be used are Cu conductors and CuNi conductors. However, these compensating conductors can also be expensive. Furthermore, they may not be suitable for certain types of thermocouples, or their properties may not be suitable for the intended application setup, for example, due to excessive stiffness. They may also be incompatible with the environment in which the temperature is to be measured. Especially for high-temperature applications, it may be impossible to obtain suitable wires.

[0006] In all cases, thermocouples with compensating leads need to be calibrated. Furthermore, thermocouples are single-use items intended for only one application, and this also applies to the corresponding compensating leads.

[0007] Therefore, there is a need for a method and apparatus that uses thermocouples without using extension wires or compensating wires.

[0008] The third type of wire used in thermocouple applications is the connecting wire, which is a simple electrical conductor used for electrical connections and is widely available.

[0009] To measure temperature using a thermocouple, the temperature of the cold junction must be known, either by measuring it with an external sensor or by adjusting the cold junction to a known temperature. In the simplest case, the cold junction is at 0°C, for example, in an ice bath. When the cold junction is not at 0°C, its temperature must be found to determine the actual hot junction temperature. For example, EP 2428780 A2 discloses a method using a temperature sensor installed near the cold junction. WO 2015032592 A1 discloses a method for determining the temperature of the cold junction by measuring a reference temperature in a processing device associated with the temperature measurement.

[0010] Alternatively, a compensation method can be applied. This compensation is called cold contact compensation. When determining high temperatures in a remote environment, measuring the cold contact temperature may be impossible or may involve complex instruments, making the measurement procedure expensive and error-prone.

[0011] Therefore, there is a need for a method and system for determining the temperature of the cold junction of a thermocouple without using extension wires or compensating wires.

[0012] The purpose of this invention is to provide an improved method for determining the temperature of the cold junction of a thermocouple.

[0013] Another objective is to propose a method for determining temperature using thermocouples without the use of extension wires or compensating wires.

[0014] Another objective is to reduce the application cost of these methods. Furthermore, these methods should be applicable to all types of thermocouples.

[0015] In addition, the method used for temperature determination should be applicable to high-temperature measurements. Furthermore, the method should be applicable to remote measurement locations.

[0016] Another object of the present invention is to provide an improved thermocouple system that can be widely used. Furthermore, the thermocouple system should reduce costs in applications, especially when using thermocouples made of precious metals.

[0017] Another objective is to provide a thermocouple device that includes a thermocouple system to determine the temperature of a high-temperature environment.

[0018] In addition, thermocouple systems and devices that do not require suitable extension wires or compensating wires should be provided. The use of thermocouple systems and devices should not be limited to a particular thermocouple or a limited temperature range.

[0019] In a first aspect, the present invention provides a method for determining the temperature of the cold junction of a thermocouple, the method comprising:

[0020] i) Provide a thermocouple at location p1 at temperature T1.

[0021] Thermocouples consist of two thermocouple leads, each including a measuring junction and a cold junction.

[0022] The thermocouple wires are connected to each other at their measuring ends at the measuring junction;

[0023] ii) Provide a temperature sensor configured to measure the temperature at position p1;

[0024] iii) Measure the temperature T1 using a temperature sensor at time point t1;

[0025] iv) Measure the voltage signal V1 of the thermocouple at time point t1;

[0026] v) Determine the temperature T of the cold junction of the thermocouple wire at time point t1 based on temperature T1 and voltage signal V1. 冷 (t1).

[0027] It should be understood that steps iii) to v) of the method are performed after steps i) and ii), and step v) is performed after steps iii) and iv).

[0028] Surprisingly, it has been found that external measurement of the temperature of the hot junction of a thermocouple, along with the associated electrical signal, is suitable for determining the reference temperature of the cold junction. This differs from commonly used methods, which only measure the temperature of the hot junction without requiring measurement of the cold junction temperature. In methods according to the prior art, the temperature of the cold junction is measured or controlled as a reference temperature. The method of the present invention and the associated thermocouple system allow for simplified measurement setup without requiring thermocouple-specific compensation wires.

[0029] Within this application, a distinction is made between "measuring" and "determining" a specific value or parameter. "Measuring" should be understood as a step during which the corresponding parameter or value is directly obtained by the appropriate device without further processing of the acquired data. Measurement may include signal conversion, such as conversion from analog to digital signals. When "determining" a parameter or value, further processing is performed on the signal obtained through appropriate means to obtain the desired parameter or value. This processing step may be, for example, a calculation step, the application of mathematical functions, and / or matching with a reference graph or table.

[0030] The method of the present invention includes providing a thermocouple comprising two thermocouple wires. As known to those skilled in the art, the two thermocouple wires are made of different materials. In other words, the first thermocouple wire comprises a first material, and the second thermocouple wire comprises a second material different from the first material. The thermocouple wires may comprise metals, such as noble metals like platinum (Pt), metals like tungsten (W), or alloys, such as noble metal alloys like platinum-rhodium (PtRh) alloys or W-containing alloys, such as those combined with rhenium (Re, WRe). In this invention, noble metals are metals selected from the group consisting of platinum, gold, and silver. Platinum metals are the so-called platinum group metals, namely platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), osmium (Os), and ruthenium (Ru).

[0031] In principle, the method of the present invention can be performed using each pair of thermocouple wires or each type of thermocouple. Preferably, at least one of the thermocouple wires contains tungsten (W) or a noble metal; more preferably, at least one of the thermocouple wires contains tungsten (W).

[0032] Tungsten-containing thermocouple wires are particularly suitable for this invention because they exhibit low brittleness even when the thermocouple wires have a small diameter. Thermocouple wires with small diameters are preferred because they have short response times. "Small" diameter should be understood as a diameter in the range of 0.01 mm to 0.5 mm.

[0033] Preferably, the diameter of the thermocouple wire is in the range of 0.01 mm to 0.5 mm, more preferably in the range of 0.05 mm to 0.4 mm, and even more preferably in the range of 0.1 mm to 0.3 mm.

[0034] In a preferred embodiment, the thermocouple is a type C thermocouple (WRe5 and WRe26 thermocouple wires), a type D thermocouple (WRe3 and WRe25 thermocouple wires), or a type G thermocouple (W and WRe26 thermocouple wires). The alloy composition in this application is given in weight percent (wt.%) and the total is 100%. For example, a WRe5 alloy consists of 5 wt.% Re, W, and unavoidable impurities. In the context of this invention, "unavoidable impurities" are impurities originating from the raw materials used or from trace amounts of chemical elements and / or compounds arising from the thermocouple wire manufacturing process. The alloy of the thermocouple wire may contain unavoidable impurities in total amounts ranging from 0 wt.-ppm to 100 wt.-ppm, for example, from 10 wt.-ppm to 100 wt.-ppm.

[0035] Preferably, the thermocouple is not a Type B thermocouple. A Type B thermocouple comprises a first thermocouple wire of PtRh30 and a second thermocouple wire of PtRh6. Type B thermocouples can be operated with copper compensating wires, which reduces the advantageous effects of the method of the present invention. Furthermore, Type B thermocouples can only be used within a limited cold junction temperature range (0°C to 40°C), and are therefore unsuitable for measurements in high-temperature environments.

[0036] Each thermocouple lead consists of a measuring end and a cold end, and they are connected to each other at the measuring junction.

[0037] Thermocouple wires can be connected, for example by welding, brazing, tightening, twisting, or other means suitable for establishing electrical contact between the measuring ends.

[0038] It should be understood that the cold ends of the thermocouple wires are not connected to each other, but are spaced apart. The cold ends together form the cold junction of the thermocouple. Typically, the cold ends are at the same temperature level. In this application, "cold junction" will be used synonymously with "cold end" of the thermocouple wires.

[0039] In a preferred embodiment, the thermocouple is a fast thermocouple, in other words, a thermocouple with a short response time. Within the scope of this invention, a fast thermocouple should be understood as a thermocouple with a measuring junction that rapidly equilibrates in response to changes in the thermal environment. For example, the measuring junction can adapt to a temperature difference of 100°C in a gaseous atmosphere (e.g., ambient air) within less than 20 seconds, preferably less than 10 seconds, even more preferably less than 5 seconds, and most preferably less than 3 seconds. In a preferred embodiment, the measuring junction can adapt to a temperature difference of 500°C within less than 20 seconds, preferably less than 10 seconds, even more preferably less than 5 seconds, and most preferably less than 3 seconds.

[0040] As is known to those skilled in the art, fast thermocouples have low thermal mass in the area of ​​the measuring junction; for example, they can have a diameter of less than 10 mm, preferably less than 8 mm, or even more preferably less than 5 mm.

[0041] Preferably, the cold contact slowly equilibrates with changes in the thermal environment. For example, for a temperature difference of 100°C, the temperature of the cold contact can change by less than 10% within a gaseous atmosphere (e.g., ambient air) for more than 20 seconds, preferably more than 40 seconds, and even more preferably more than 100 seconds. In a preferred embodiment, for a temperature difference of 500°C, the temperature of the cold contact can change by less than 10% within a gaseous atmosphere (e.g., ambient air) for more than 20 seconds, preferably more than 40 seconds, and even more preferably more than 100 seconds.

[0042] Preferably, the cold junction of the thermocouple is insulated. The cold junction can be embedded, for example, in an insulating material, such as a refractory material like a ceramic oxide. Alternatively, the cold junction can be embedded in a non-insulating body, in which case the body can have the mass to insulate the cold junction. This insulation ensures that the thermocouple's measuring junction reaches thermal equilibrium faster than the cold junction. In the region of the cold junction, the diameter of the insulating material can exceed 10 mm, more preferably exceeding 20 mm, and even more preferably exceeding 30 mm.

[0043] In a preferred embodiment, for a temperature change of 100°C, the measuring contact balances at a speed more than 10 times faster than the cold contact, preferably more than 20 times faster, and even more preferably more than 100 times faster. In an even more preferred embodiment, for a temperature change of 500°C, the measuring contact balances at a speed more than 10 times faster than the cold contact, preferably more than 20 times faster, and even more preferably more than 100 times faster.

[0044] As those skilled in the art know, in use, the cold end of the thermocouple wire is electrically connected directly or preferably via a connecting device to a suitable measuring device. A suitable measuring device is a unit configured to receive and process the signal acquired by the thermocouple.

[0045] In such cases, the cold end of the thermocouple wire can be connected to a pair of connecting devices at the cold junction.

[0046] Preferably, the connecting device is a conductive wire, more preferably a connecting conductor. Suitable materials for the connecting conductor are known to those skilled in the art, and they can be selected, for example, from the group consisting of copper (Cu), copper-nickel (CuNi), nickel-chromium alloys (nickel-based alloys containing chromium (Cr)), and nickel-aluminum alloys (Ni-based alloys containing aluminum (Al), manganese (Mn), and silicon (Si). Preferably, both connecting devices are made of the same material. It has proven particularly advantageous for the method of the present invention that compensating conductors are not required as connecting devices; in other words, the connecting devices do not need to be matched to the thermoelectric behavior of the thermocouple wires. Therefore, the total cost of the thermocouple system, including the thermocouple and the connecting devices, can be kept low.

[0047] When the connecting devices are made of the same material (e.g., both connecting devices are made of copper wire), these wires do not introduce any additional voltage signal, and the voltage signal originates solely from the type of thermocouple used and the temperature difference between the measuring contacts and the cold contacts. Furthermore, these types of connecting devices can be used with each type of thermocouple.

[0048] Thermocouples can be contained in or covered by protective devices, such as in tubes (preferably quartz glass tubes) or coatings (e.g., refractory coatings made of ceramic materials).

[0049] A thermocouple may be incorporated into a probe configured to measure additional parameters of a high-temperature environment. The probe should be understood as a sensor assembly carrying at least one sensor that can be brought into the environment (e.g., a high-temperature environment) where its parameters are to be determined or measured. Such a probe may include additional sensor elements, such as electrochemical sensors, electromagnetic sensors, optical sensors, sensors for detecting voltage, sensors for detecting current, and / or sensors for detecting resistance. Preferably, the sensor assembly includes means for determining chemical composition, such as an oxygen detection element, preferably an oxygen detection element for determining oxygen in the high-temperature environment. Preferably, the high-temperature environment is a pool of molten metal. The probe may include additional components, such as a protective body made of metal or refractory material and / or connectors for attaching sensor elements.

[0050] A thermocouple is provided at position p1 at temperature T1. In other words, a thermocouple is provided at position p1, and the temperature at position p1 is temperature T1. To put it another way, T1 is not the temperature of the thermocouple itself, but rather the temperature of the environment in which the thermocouple is located at position p1. The thermocouple or components thereof may or may not have temperature T1.

[0051] Position p1 is typically the starting position. Preferably, the thermocouple is configured to move from the starting position p1 to a second position p2, which is typically the measurement position. Typically, the second position p2 is in a high-temperature environment where the temperature should be determined. In other words, the thermocouple is preferably not permanently installed within the thermocouple system in which it is set. Therefore, the method of the present invention is particularly suitable for disposable thermocouples intended for single use. Such disposable thermocouples can be used, for example, to obtain the temperature of a high-temperature environment (during which the thermocouple and / or associated measuring equipment will be consumed or destroyed), such as the measurement of the temperature of a molten metal pool.

[0052] The method includes providing a temperature sensor. Suitable temperature sensors are known to those skilled in the art, such as resistance temperature detectors (RTDs), thermistors, infrared detectors, or integrated circuit (IC) temperature sensors. Additional thermocouples, such as type K, type E, type J, or type T thermocouples, may also be used. The combinations of thermocouple leads used for these types of thermocouples are known to those skilled in the art.

[0053] A temperature sensor is configured to measure the temperature at position p1. Preferably, the temperature sensor is configured to measure the temperature near the measuring junction of the thermocouple at position p1. To ensure that the temperature measured by the temperature sensor accurately reflects the temperature of the measuring junction, the temperature sensor can be positioned in close thermal proximity to the measuring junction.

[0054] It should be understood that "measuring" the temperature at location p1 can also refer to determining the temperature using a suitable device, such as when using an additional thermocouple as a temperature sensor.

[0055] This method is based on the measurement of temperature T1 at position p1. In this invention, it is assumed that the measuring junction has temperature T1 at time t1. Therefore, it may be preferable that the method includes an equilibration period before further steps. In other words, the method may include an equilibration period before t1.

[0056] During the equilibration period, the measuring contact can achieve thermal equilibrium with the temperature environment at position p1.

[0057] During the equilibration period, the voltage signal of the thermocouple can be tracked. Preferably, the voltage signal is tracked by a suitable measuring device and / or a suitable processing device. The end of the equilibration period can preferably be determined by the stable voltage signal emitted by the thermocouple during a predetermined time interval. The length of the time interval can be, for example, in the range of 1 s to 10 s, preferably in the range of 2 s to 8 s. The stable voltage signal is preferably a signal that varies by no more than 50 µV, preferably no more than 20 µV, and even more preferably no more than 10 µV during the predetermined time interval.

[0058] The method involves measuring temperature T1 using a temperature sensor at time t1. In other words, measuring the temperature T1 at position p1 at time t1.

[0059] The thermocouple's measuring junction has a temperature T1 at position p1 at time t1. In other words, the temperature sensor measures the temperature of the measuring junction at time t1.

[0060] The method involves measuring the voltage signal V1 of the thermocouple at time point t1. It should be understood that the voltage signal V1 measured at time point t1 is caused by the temperature difference between the measuring junction and the cold junction of the thermocouple (i.e., between the hot junction and the cold junction). If the measuring junction and the cold junction have the same temperature, the measured voltage signal V1 will be 0 (zero).

[0061] This measurement can be performed using a suitable measuring device configured to receive signals from the thermocouple, such as a voltmeter connected to the cold junction of the thermocouple. The measuring device can be a component of a suitable processing unit.

[0062] The method includes determining the temperature T of the cold junction of the thermocouple wire at time point t1 based on temperature T1 and voltage signal V1. 冷 (t1).

[0063] In the method according to the prior art, the temperature of the cold junction is measured, converted into a voltage, and then this voltage is algebraically summed with the voltage measured from the thermocouple. The result of this summation is then inserted into a table (which is stored, for example, in a processing unit), from which the temperature of the measured junction can be determined. In the method according to the invention, the temperature of the cold junction is not measured but determined. The temperature of the cold junction is determined using a voltage obtained for a known temperature of the hot junction, for example, by comparing this value with a known table or formula provided in a suitable processing unit.

[0064] Because thermocouple voltage and temperature are not linearly related, the conversion from voltage to temperature usually requires a complex polynomial function specific to the thermocouple type, or optionally a standard lookup table for thermocouple voltage and temperature.

[0065] Preferably, standardized thermocouples with standardized thermocouple leads, such as those described in ASTM E230 or NEN-EN-IEC 60584-1:2013, are used, thus allowing the use of established formulas and / or tables. The processing device can store such functions and / or tables for standardized thermocouples.

[0066] The temperature T of the cold junction of the thermocouple wire at time t1 is determined based on temperature T1 and voltage signal V1. 冷 (t1) can be performed by a processing device, as is known to those skilled in the art.

[0067] Temperature T can be determined, for example, based on the application of functions and / or empirical tables. 冷 (t1). In the given context, the function should be understood as a formula that correlates the measured voltage signal with the temperature of the cold junction.

[0068] In a preferred embodiment, the voltage signal (V) that will be obtained by the thermocouple for the measuring junction having a cold junction of 0°C and a measuring junction of temperature T1 can be used as a basis. 0℃ The temperature T is determined by calculating the difference ΔV(t1) between (T1) and the measured voltage signal V1. 冷 (t1):

[0069] ΔV(t1)=V 0℃ (T1)-V1.

[0070] The voltage signal (V) that will be obtained by a thermocouple with a cold junction at 0°C and a measuring junction at temperature T1. 0℃ (T1) can be derived from standardized tables and / or formulas. The corresponding temperature...

[0071] T(ΔV(t1))=T 冷 (t1)

[0072] It can be derived from standardized tables and / or formulas.

[0073] The method may include providing a processing device configured to process signals from the thermocouple and a temperature sensor to determine the temperature of the cold junction of the thermocouple wires. The processing device may include a measuring device configured to measure the voltage signal of the thermocouple.

[0074] The measuring device can also be provided as a separate unit, preferably connected to the processing device.

[0075] The method may include providing a data storage device configured to store the temperature of the cold junction of the thermocouple wires, and / or the voltage signal V that the thermocouple will receive for a measuring junction having a cold junction at 0°C and a measuring junction at a temperature T1. 0℃ The difference ΔV(t1) between temperature T1 and the measured voltage signal V1. Preferably, the data storage device is configured to store the temperature Tc of the cold junction of the thermocouple wire at time point t1, derived from temperature T1 and voltage signal V1. 冷 (t1), and / or the voltage signal V that will be obtained by the thermocouple with a cold junction at 0°C and a measuring junction at temperature T1. 0℃ The difference ΔV(t1) between (T1) and the voltage signal V1 measured at time t1. The data storage device can be a separate component or can be integrated into the processing device.

[0076] In a second aspect, the present invention provides a thermocouple system adapted to perform the method of the present invention for determining the temperature of the cold junction of a thermocouple.

[0077] In a third aspect, the present invention provides a method for determining the temperature of a high-temperature environment using a thermocouple, the method comprising the steps of the method of the present invention for determining the temperature of the cold junction of the thermocouple, and

[0078] vi) Move the thermocouple from position p1 to a second position p2 at temperature T2 in a high-temperature environment;

[0079] vii) Measure the voltage signal V2 of the thermocouple at time t2;

[0080] viii) Based on the temperature T of the cold junction at time point t1 冷 (t1) and voltage signal V2 are used to determine the temperature T2 of the high-temperature environment at time t2.

[0081] Steps vi) to viii) of the method for determining the temperature of a high-temperature environment using a thermocouple are performed after steps i) to v) of the method for determining the temperature of the cold junction of a thermocouple. Steps vi), vii), and viii) are performed sequentially in a specified order.

[0082] Surprisingly, it has been found that when a thermocouple is rapidly moved from its initial position to the measurement position, the temperature of the cold junction, determined at the initial time point, can be used to determine the temperature of a remote high-temperature environment. Therefore, the method of this invention allows for the determination of the temperature of a remote environment without the need for further measurement of the cold junction temperature. Furthermore, the temperatures of the processing instrument and the temperature sensor do not need to be the same. Even the temperature of the processing instrument becomes irrelevant.

[0083] Since the temperature of the cold junction is known, there is no need for expensive extension wires or compensating wires, which significantly reduces the cost of measurement and the required equipment.

[0084] The method of this invention is based on the assumption that the thermocouple's measuring junction rapidly reaches thermal equilibrium with the high-temperature environment, and that the temperature change of the cold junction is negligible between time points t1 and t2. Therefore, it is not necessary to measure or determine the temperature of the cold junction at time point t2 when temperature T2 is determined, which simplifies the required measuring equipment and thus reduces measurement costs.

[0085] Preferably, the high-temperature environment is a pool of molten metal. The molten metal typically has a temperature above 600°C, particularly above 800°C, and preferably above 1000°C. The temperature of the molten metal can, for example, range from 600°C to 1800°C, more preferably from 800°C to 1700°C. Preferably, the molten metal is molten steel. The terms "molten" or "molten metal" do not exclude the presence of any solid or gaseous portion, including, for example, the non-molten portion of the corresponding metal. The temperature of a molten metal varies and generally depends on the composition of the metal and the stage of the melting process.

[0086] The aspect of the present invention relating to a method for determining the temperature of the cold junction of a thermocouple is also an aspect of the present invention relating to a method for determining the temperature of a high-temperature environment.

[0087] The method also includes moving the thermocouple from position p1 to a second position p2 at temperature T2 in a high-temperature environment. In other words, the thermocouple is moved from the initial position p1 to the measuring position p2. This movement can be performed without the aid of an external moving device, and the method of movement is not further limited. The thermocouple can be moved and / or accelerated, for example, by gravity or by an accelerator.

[0088] The method may include providing a moving device configured to move the thermocouple from position p1 to a second position p2. Suitable moving devices include, for example, acceleration devices, dropping devices, or spray guns used in metallurgical facilities.

[0089] The method involves measuring the voltage signal V2 of the thermocouple at time point t2. It should be understood that the measurement of the voltage signal V2 is performed after the thermocouple has moved to the second position p2, and time point t2 is later than time point t1. In other words, the voltage signal V2 is measured when the thermocouple is at the second position p2 at time point t2.

[0090] This method includes temperature T 冷 The temperature T2 of the high-temperature environment at time t2 is determined using (t1) and the voltage signal V2. The determination of temperature T2 is performed after measuring the voltage signal V2. In other words, it is based on the temperature T of the cold junction obtained at time t1. 冷 Temperature T2 is calculated using the voltage signal V2 measured at time t1 and time t2.

[0091] Based on temperature T 冷 The temperature T2 of the high-temperature environment at time t2 can be determined by the processing device, as is known to those skilled in the art, using (t1) and voltage signal V2.

[0092] Temperature T2 can be determined, for example, based on the application of functions and / or empirical tables. In the given context, a function should be understood as a formula that correlates a voltage signal with the cold contact temperature and the measured contact temperature.

[0093] In a preferred embodiment, the temperature value T can be used... 热 (It refers to the voltage signal V2) and the temperature T of the cold junction determined at time point t1. 冷 (t1) is added together to determine temperature T2:

[0094] T2=T 冷 (t1)+T 热 .

[0095] Temperature T 热 It can be derived from standardized tables and / or formulas based on V2:

[0096] T(V2)=T 热 .

[0097] When using a thermocouple that exhibits linear behavior over the measured temperature range, it is particularly appropriate to determine the temperature T2 by adding the two temperature values.

[0098] In a fourth aspect, the present invention provides a thermocouple device adapted to perform the method of the present invention for determining the temperature of a high-temperature environment.

[0099] In a fifth aspect, the present invention provides an alternative method for determining the temperature of a high-temperature environment using a thermocouple, the method comprising:

[0100] i) Provide a thermocouple at location p1 at temperature T1.

[0101] Thermocouples consist of two thermocouple leads, each including a measuring junction and a cold junction.

[0102] The thermocouple wires are connected to each other at their measuring ends at the measuring junction;

[0103] ii) Provide a temperature sensor configured to measure the temperature at position p1;

[0104] iii) Measure the temperature T1 using a temperature sensor at time point t1;

[0105] iv) Measure the voltage signal V1 of the thermocouple at time point t1;

[0106] v) Calculate the voltage signal V that will be obtained by the thermocouple for a cold junction with a temperature of 0°C and a measuring junction with a temperature of T1. 0℃ (T1) is the difference ΔV(t1) between the measured voltage signal V1 and the voltage signal V1.

[0107] vi) Move the thermocouple from position p1 to a second position p2 at temperature T2 in a high-temperature environment;

[0108] vii) Measure the voltage signal V2 of the thermocouple at time t2;

[0109] viii) The voltage signal V obtained by the thermocouple for the measuring junction with a cold junction at 0°C and a measuring junction at temperature T1. 0℃ The temperature T2 of the high-temperature environment at time t2 is determined by the difference ΔV(t1) between (T1) and the voltage signal V1 measured at time t1, and the voltage signal V2.

[0110] It should be understood that steps vi) to viii) of the method are performed after steps i) to v), and steps vi), vii) and viii) are performed sequentially in a specified order.

[0111] This method is an alternative to the method described in the third aspect of the invention. Steps i) to iv), vi), and vii) are equivalent to the steps described as for the alternative method for determining the temperature of a high-temperature environment as described above. Instead of using the temperature of the cold junction at position p1 at time t1, the desired temperature T2 is determined using a voltage signal. Therefore, there is no need to calculate the cold junction temperature at t1 on an ad hoc basis. This calculation method can provide more accurate results, especially when the thermocouple does not show a linear relationship between temperature and voltage signals.

[0112] In step v), the voltage signal V that will be obtained by the thermocouple for the cold junction with a temperature of 0°C and the measuring junction with a temperature of T1 is calculated. 0℃ The difference ΔV(t1) between (T1) and the measured voltage signal V1:

[0113] ΔV(t1)=V 0℃ (T1)-V1.

[0114] The voltage signal (V0℃(T1)) obtained for a thermocouple with a cold junction at 0℃ and a measuring junction at temperature T1 can be derived from standardized tables and / or formulas.

[0115] In step viii), the voltage signal V will be obtained from the thermocouple for the measuring junction with a cold junction at 0°C and a measuring junction at temperature T1. 0℃ Temperature T2 is determined by the difference ΔV(t1) between (T1) and the voltage signal V1 measured at time t1, and the voltage signal V2.

[0116] Preferably, the temperature T2 is determined based on the difference between the voltage signal V2 obtained by adding a voltage signal to a thermocouple with a cold junction at 0°C and the voltage signal V1 measured at time point t1:

[0117] V 0℃ (T2)=V2+ΔV(t1).

[0118] voltage signal V 0℃ (T2) corresponds to the voltage signal that will be obtained for a thermocouple with a cold junction at 0°C and a measuring junction at temperature T2.

[0119] Temperature T2 can be based on V 0℃ (T2) Derived from standardized tables and / or formulas:

[0120] T(V 0℃ (T2))=T2.

[0121] In a sixth aspect, the present invention provides a thermocouple device adapted to perform an alternative method of the present invention for determining the temperature of a high-temperature environment.

[0122] In a seventh aspect, the present invention provides a thermocouple system for determining the temperature of the cold junction of a thermocouple, the thermocouple system comprising:

[0123] I) Thermocouple at position p1

[0124] The thermocouple includes two thermocouple wires, each thermocouple wire including a measuring end and a cold junction, wherein the thermocouple wires are connected to each other at their measuring ends at a measuring junction, and wherein the cold junctions are connected to a pair of connecting devices at a cold junction.

[0125] II) Temperature sensor, wherein the temperature sensor is configured to measure the temperature at position p1;

[0126] III) A pair of connecting devices, each connecting device including a cold contact connection end and an opposite end.

[0127] The cold end of the thermocouple wire is connected to the cold junction connection end of the pair of connection devices at the cold junction point;

[0128] IV) Processing apparatus, which is connected to the connecting apparatus at their opposite ends, and

[0129] a) Configured to process signals from thermocouples and temperature sensors to determine the temperature of the cold junction of the thermocouple leads, and / or

[0130] b) Configured to process signals from thermocouples and temperature sensors, and to calculate the voltage signal V that will be obtained for a thermocouple with a cold junction at 0°C and a measuring junction at temperature T1. 0℃ (T1) is the difference ΔV between the measured voltage signal and the voltage signal.

[0131] The thermocouple system of the present invention is suitable for determining the temperature of the cold junction of a thermocouple. Surprisingly, it has been found that devices for externally measuring the temperature of the hot junction of a thermocouple and the associated electrical signal are suitable for determining a reference temperature for the cold junction, and allow for simpler and more cost-effective system design. In prior art devices, the temperature of the cold junction is measured or controlled as a reference temperature. The method and associated thermocouple system of the present invention allow for simplified measurement setups without requiring thermocouple-specific compensation wires. Furthermore, the measurement of the reference temperature can be performed in an easily accessible location.

[0132] Thermocouple systems include thermocouples. For the sake of brevity, referring to the foregoing, one can understand suitable and preferred embodiments relating to thermocouples in connection with the methods of the present invention, which also apply to thermocouples in the thermocouple systems of the present invention.

[0133] A thermocouple is provided at position p1 within the thermocouple system. Preferably, the thermocouple is configured to move from position p1 to a second position p2. In other words, the thermocouple is not installed in a fixed position or at a fixed location within the thermocouple system. Therefore, the thermocouple can preferably be a disposable thermocouple intended for single use.

[0134] Typically, position p1 is the starting position, and the second position p2 is the measuring position. Preferably, the thermocouple is configured to move from the starting position p1 to the measuring position p2. Typically, the measuring position p2 is a position in a high-temperature environment where the temperature should be determined.

[0135] The thermocouple system includes a temperature sensor configured to measure the temperature at position p1. Suitable temperature sensors are known to those skilled in the art. For simplicity, reference is made above to understand suitable and preferred embodiments relating to temperature sensors in connection with the method of the present invention, which also apply to temperature sensors in the thermocouple system of the present invention.

[0136] Thermocouple systems include a pair of connection devices. Suitable connection devices are known to those skilled in the art. For the sake of brevity, reference is made above to understand suitable and preferred embodiments relating to connection devices in connection with the method of the present invention, which also apply to the connection devices of the thermocouple system of the present invention.

[0137] Each of the pair of connecting devices includes a cold junction connection end and an opposite end. Each thermocouple wire in the thermocouple includes a measuring end and a cold junction. The cold junction of the thermocouple wire is connected to the cold junction connection end of the connecting device at the cold junction. Suitable means and methods for connecting the thermocouple wires to the connecting device are known to those skilled in the art.

[0138] The thermocouple system includes a processing unit configured to process signals from the thermocouple and a temperature sensor to determine the temperature of the cold junction of the thermocouple wires. The processing unit may optionally or additionally be configured to process the signals from the thermocouple and the temperature sensor to calculate the voltage signal V that would be obtained for a thermocouple having a cold junction at 0°C and a measuring junction at a temperature T1. 0℃ The difference ΔV between the measured voltage signal and the voltage signal.

[0139] For the sake of brevity, refer to the above content related to the method of the present invention to understand suitable and preferred embodiments involving the processing of the obtained signals, which also apply to the processing of the thermocouple system of the present invention.

[0140] The processing unit may include a measuring device configured to receive and process signals obtained from the thermocouple. The measuring device may also be provided as a separate unit, preferably connected to the processing unit.

[0141] The processing devices are connected to the connecting device at their opposite ends. Suitable means and methods for connecting the processing devices to the connecting device are known to those skilled in the art.

[0142] The processing device can be configured to track the voltage signal of the thermocouple during an equilibration period. Preferably, the processing device is configured to determine the end of the equilibration period. The end of the equilibration period can be determined, for example, by the stable voltage signal emitted by the thermocouple during a predetermined time interval. The length of the time interval can be, for example, in the range of 1 s to 10 s, preferably in the range of 2 s to 8 s. The stable voltage signal is preferably a signal that varies by no more than 50 µV, preferably no more than 20 µV, and even more preferably no more than 10 µV during the predetermined time interval.

[0143] Thermocouple systems may include a data storage device configured to store the temperature of the cold junction of the thermocouple wires, and / or the voltage signal V that the thermocouple will receive for a cold junction with a temperature of 0°C and a measuring junction with a temperature T1. 0℃ The difference ΔV between (T1) and the measured voltage signal V1. Preferably, the data storage device is configured to store the temperature T of the cold junction of the thermocouple wire at time point t1, derived from the temperature T1 and the voltage signal V1. 冷 (t1), and / or the voltage signal V that will be obtained by the thermocouple with a cold junction at 0°C and a measuring junction at temperature T1. 0℃ The difference ΔV(t1) between (T1) and the voltage signal V1 measured at time t1. The data storage device can be a separate component or can be integrated into the processing device.

[0144] In an eighth aspect, the present invention provides a thermocouple device for determining the temperature of a high-temperature environment, the thermocouple device comprising the thermocouple system of the present invention, and

[0145] V) A moving device configured to move the thermocouple from position p1 to a second position p2;

[0146] The thermocouple is configured to move from position p1 to a second position p2 in a high-temperature environment.

[0147] Furthermore, the processing device is configured to determine the temperature of the high-temperature environment by processing the signal from the thermocouple at the second position p2, and

[0148] a) The temperature of the cold junction at the initial position p1, and / or

[0149] b) The voltage signal V obtained by a thermocouple with a cold junction at 0°C and a measuring junction at temperature T1. 0℃ (T1) is the difference ΔV between the measured voltage signal V1 and the voltage signal T1.

[0150] The thermocouple device includes a moving device configured to move the thermocouple from position p1 to a second position p2. Suitable moving devices include, for example, acceleration devices, dropping devices, or spray guns used in metallurgical facilities.

[0151] The thermocouple device is configured to determine the temperature of the high-temperature environment by processing the signal from the thermocouple at the second position p2 and the temperature of the cold junction of the thermocouple wire at position p1.

[0152] The processing unit of the thermocouple device is optionally or additionally configured to process the signal from the thermocouple at the second position p2 and the voltage signal V that will be obtained from the thermocouple having a cold junction at 0°C and a measuring junction at temperature T1. 0℃ The temperature of the high-temperature environment is determined by the difference ΔV between (T1) and the measured voltage signal V1.

[0153] For the sake of brevity, refer to the above content related to the method of the present invention to understand suitable and preferred embodiments involving the processing of the obtained signals, which also apply to the processing of the thermocouple device of the present invention.

[0154] The following schematic diagrams and embodiments illustrate aspects of the invention to aid in understanding the invention in conjunction with some exemplary examples. However, it should be understood that the invention is not limited to the precise arrangements and tools shown. Elements in the drawings are not necessarily to scale relative to each other. Similar reference numerals denote corresponding similar parts. In this document:

[0155] Figure 1 A schematic diagram of a thermocouple measurement circuit is shown.

[0156] Figure 2 A thermocouple system according to the present invention is shown;

[0157] Figure 3 Another embodiment of the thermocouple system according to the present invention is shown;

[0158] Figure 4 The temperature development of the hot and cold junctions of the thermocouple is shown during the measurement sequence.

[0159] Figure 1 A schematic diagram of a thermocouple measurement circuit according to the prior art is shown. Thermocouple wire 2 of thermocouple 1 is connected at measuring junction 3 (often also called the hot junction). The other end of thermocouple wire 2 (i.e., the cold junction 4) is electrically connected to compensating wire or extension wire 6, forming cold junction 5. The extension wire is typically made of the same material as the thermocouple wire, while the compensating wire has thermoelectric properties that match the characteristics of the thermocouple wire within a certain temperature range. The compensating wire or extension wire 6 is connected to a suitable measuring instrument 7, typically a voltmeter. The thermocouple wire can also be directly connected to the measuring instrument. In use, the hot junction is placed in the environment where the temperature is to be measured, and the cold junction is located away from the measurement location. The cold junction can also be placed inside or on the measuring instrument. To determine the desired temperature, the voltage between the cold junction and the hot junction is measured, and the temperature of the cold junction is measured or determined at the same time point. The desired temperature is then calculated using this parameter pair. Specifically, a reference temperature is applied to the characteristic function to generate a value for the characteristic function at the reference temperature, and this value is added to the measured voltage to obtain a value for the characteristic function at the sensing temperature of the measuring junction. Then, using this value of the characteristic function, the sensing temperature is retrieved from a table that associates the sensing temperature of the thermocouple with the value of the characteristic function.

[0160] Figure 2 A illustrates a thermocouple system 20 according to the invention, wherein thermocouple 1 is at an initial position p1 at a first temperature T1. A high-temperature environment with a temperature T2 is also shown, in which thermocouple 1 can be moved by a thermocouple device including a moving device (not shown), such as a spray gun or a launching device.

[0161] The cold junction 5 of thermocouple 1 is connected to measuring instrument 7 via connecting wire 21. This measuring instrument can process the voltage signal of thermocouple 1. In the illustrated embodiment, instrument 7 is placed in a different temperature environment than thermocouple 1 at a different temperature T3. However, the temperature of the other instrument is irrelevant to the present invention. Thermocouple system 20 includes temperature sensor 22, which is placed next to measuring junction 3 at initial position p1. Measuring instrument 7 and temperature sensor 22 are connected to processing instrument 23, which can process the signals measured by the sensors (i.e., thermocouple 1 and temperature sensor 22).

[0162] Figure 2 B illustrates a thermocouple system 20 according to the invention, wherein thermocouple 1 is in the measuring position p2, i.e., in a high-temperature environment. Thermocouple 1 has been moved from the initial position p1 to the high-temperature environment. Except for the portion of the connecting wire 21 that remains connected to thermocouple 1 and is typically pulled backward during the movement, the other components of the device are static. After thermocouple 1 reaches the high-temperature environment, a second voltage signal is obtained. The measuring contact 3 is configured to have a low thermal mass, which allows for rapid thermal equilibrium with the high-temperature environment. Based on this voltage signal and the stored value of the cold contact 5 at the start of the measurement (corrected voltage signal or determined temperature), the processing unit 23 determines the temperature of the measuring contact 3, which corresponds to the temperature T2 of the high-temperature environment.

[0163] Figure 3 Another embodiment of the thermocouple system 20 according to the invention, in the initial position p1, is shown. The measuring instrument 7 is integrated into the processing instrument 23, which is located in a different temperature environment than the thermocouple.

[0164] Figure 4 The thermal junction (T) of the thermocouple is shown during the determination of the temperature of the high-temperature environment using the method of the present invention. 热 ) and cold contact (T) 冷 The temperature development of the thermocouple. Before measurement initialization, the thermocouple can be stored in a remote location where the cold junction and measuring junction are in thermal equilibrium at temperature T0. When the thermocouple is brought to the initial location, the hot junction heats up rapidly and reaches thermal equilibrium with the environment at temperature T1. Depending on the duration between the thermocouple delivery and the initialization of the measurement procedure, the cold junction may reach the same temperature, maintain its initial temperature, or have a temperature between T0 and T1.

[0165] At the start of the measurement (at time t1), the voltage signal from the thermocouple is obtained, and the temperature T1 is measured simultaneously by an external temperature sensor. Using these measurement signals, the processing unit calculates the temperature of the cold junction at time t1. The processing unit can store the corresponding voltage and temperature values ​​of the cold junction at that time point.

[0166] Subsequently, the thermocouple is rapidly brought to a high-temperature environment with a temperature of T2. Due to its low thermal mass, the measuring junction quickly equilibrates and adapts to temperature T2, while the temperature of the cold junction remains constant. At time t2, the voltage signal of the thermocouple is obtained again and used together with the known temperature of the cold junction at t1 to calculate temperature T2. Example

[0167] All values ​​below are based on NEN-EN-IEC 60584-1:2013. The temperature of the molten steel pool is measured using a thermocouple apparatus consisting of an S-type thermocouple surrounded by a 3mm quartz glass tube (thermocouple wire diameter: 50µm, cold junction embedded in the ceramic body) and Cu connecting wires. A voltmeter is used as the measuring instrument and is installed at a remote location with a temperature environment of 40°C. The temperature sensor (PT100) is located at a temperature environment of 80°C (T1), which is the starting position of the thermocouple prior to the measurement sequence.

[0168] When the thermocouple is moved from its storage location (e.g., at a temperature of 40°C) to its starting position, the voltmeter will begin recording a voltage signal because the thermocouple is being stored at a temperature different from the starting position, and the hot junction will quickly adapt to the temperature T1. Depending on the dwell time, the voltage will gradually evolve until the hot junction reaches thermal equilibrium with the starting position temperature.

[0169] At the start of the measurement sequence, the voltage signal V1 at time point t1 is obtained. It reflects the temperature difference between the hot junction (T1) and the cold junction at that time point. It is assumed that the cold junction has reached a temperature of 50°C at time point t1 (this temperature is unknown at this point) (T...). 冷 (t1)), then the obtained voltage V1 corresponds to T1 and T 冷 Temperature difference between (t1):

[0170] V1=V(T 热 (t1)–T 冷 (t1))=V(T1–T 冷 (t1))=V(80℃–T 冷 (50℃))=203µV.

[0171] Thermocouples with cold junctions at 0°C will be used to measure the voltage signal V at T1. 0℃ This can be obtained from the standardized table of thermocouples available for the type used:

[0172] V 0℃ (T1)=V(T1–T 冷 (0℃)) = V(80℃) = 502µV.

[0173] The difference between the theoretical voltage signal and the measured voltage signal can then be used to calculate the temperature of the cold junction (again, based on a standardized table):

[0174] ΔV(t1)=V 0℃ (T1)-V1=502µV–203µV=299µV

[0175] T(ΔV(t1)=299µV)=50℃.

[0176] The initial temperature of the thermocouple or instrument is irrelevant to these calculations.

[0177] To subsequently determine the temperature of the high-temperature environment, the temperature of the cold contact, and the voltage signal measured at t1.

[0178] When the measurement sequence begins shortly after t1, the thermocouple is brought to the environment of interest at temperature (T2), for example, to a pool of molten metal at a temperature of 1,600°C. The hot junction rapidly equilibrates to the temperature of this environment, while the temperature of the cold junction remains constant for the time required to obtain the measurement.

[0179] At time t2, a voltage signal V2 is obtained at temperature T2, which corresponds to the hot junction with an unknown temperature T2.

[0180] The temperature difference between the known temperatures of the cold junction.

[0181] V2=V(T 热 (t2)–T 冷 (t1))=V(T2–T 冷 (t1)).

[0182] The voltage signal obtained using the 0°C cold junction can be corrected using the previously stored voltage signal t1:

[0183] V 0℃ (t2)=V 0℃ (T2)=V2+ΔV(t1).

[0184] In this embodiment, a voltage signal V2 = 16.476µV will be obtained, which can be corrected to...

[0185] V 0℃ (T2)=16.476µV+299µV=1.677µV

[0186] Referring again to the reference table, the temperature of the molten metal pool can be obtained.

[0187] T(V=1.677µV)=1.600℃.

[0188] Those skilled in the art will understand that the above method is applicable to all types of thermocouples. However, in cases where the thermocouple exhibits linear behavior, the temperature difference can be calculated directly, omitting the calculation of the voltage value.

[0189] Figure Labels

[0190] 1 thermocouple

[0191] 2 thermocouple wires

[0192] 3 Measurement contacts / thermal contacts

[0193] 4. Cold junction of thermocouple wires

[0194] 5 cold joints

[0195] 6. Compensating conductors or extension conductors

[0196] 7 Measuring Instruments

[0197] 20 thermocouple system

[0198] 21 Connecting wires

[0199] 22 Temperature Sensor

[0200] 23 Processing Instruments

[0201] T1 First Temperature

[0202] T2 Second Temperature / Temperature of High-Temperature Environment

[0203] T3 Third Temperature

[0204] p1 First position / Starting position

[0205] p2 Second position / Measurement position

Claims

1. A method for determining the temperature of the cold junction of a thermocouple, the method comprising: i) Provide a thermocouple at location p1 at temperature T1. The thermocouple described herein comprises two thermocouple leads, each thermocouple lead including a measuring junction and a cold junction. The thermocouple wires are connected to each other at their measuring ends at the measuring junction; ii) Provide a temperature sensor configured to measure the temperature at position p1; iii) Measure the temperature T1 using the temperature sensor at time point t1; iv) Measure the voltage signal V1 of the thermocouple at time point t1; v) Determine the temperature T of the cold junction of the thermocouple wire at time point t1 based on the temperature T1 and the voltage signal V1. 冷 (t1).

2. The method of claim 1, wherein the temperature T is determined based on the calculation of the difference ΔV(t1) between the voltage signal obtained by the thermocouple for the measuring junction having a cold junction at 0°C and a measuring junction at a temperature T1 and the measured voltage signal V1. 冷 (t1).

3. The method according to claim 1 or 2, wherein the thermocouple is configured to move from position p1 to a second position p2.

4. The method according to any one of the preceding claims, wherein at least one of the thermocouple wires comprises tungsten (W) or a noble metal.

5. The method according to any one of the preceding claims, wherein the thermocouple is a fast thermocouple.

6. A thermocouple system suitable for performing the method according to claims 1 to 5.

7. A method for determining the temperature of a high-temperature environment using a thermocouple, the method comprising the steps of the method for determining the temperature of the cold junction of a thermocouple according to claims 1 to 5, and... vi) Move the thermocouple from position p1 to a second position p2 at temperature T2 in the high-temperature environment; vii) Measure the voltage signal V2 of the thermocouple at time point t2; viii) Based on the temperature T of the cold junction at time t1 冷 (t1) and the voltage signal V2 determine the temperature T2 of the high-temperature environment at the time point t2.

8. The method of claim 7, wherein the temperature value T representing the voltage signal V2 is used. 热 The temperature T of the cold junction as determined at time point t1 冷 (t1) are added together to determine temperature T2.

9. A method for determining the temperature of a high-temperature environment using a thermocouple, the method comprising: i) Provide a thermocouple at location p1 at temperature T1. The thermocouple described herein comprises two thermocouple leads, each thermocouple lead including a measuring junction and a cold junction. The thermocouple wires are connected to each other at their measuring ends at the measuring junction; ii) Provide a temperature sensor configured to measure the temperature at position p1; iii) Measure the temperature T1 using the temperature sensor at time point t1; iv) Measure the voltage signal V1 of the thermocouple at time point t1; v) Calculate the voltage signal V that will be obtained by the thermocouple for a cold junction with a temperature of 0°C and a measuring junction with a temperature of T1. 0℃ (T1) is the difference ΔV(t1) between the measured voltage signal V1 and the voltage signal V1. vi) Move the thermocouple from position p1 to a second position p2 at temperature T2 in the high-temperature environment; vii) Measure the voltage signal V2 of the thermocouple at time point t2; viii) Based on the voltage signal V2 and the voltage signal V obtained by the thermocouple for the cold junction with a cold junction at 0°C and the measuring junction at a temperature T1, 0℃ The temperature T2 of the high-temperature environment at time t2 is determined by the difference ΔV(t1) between (T1) and the voltage signal V1 measured at time t1.

10. A thermocouple device suitable for performing the method according to claims 7 to 8 or 9.

11. A thermocouple system for determining the temperature of the cold junction of a thermocouple, the thermocouple system comprising: I) Thermocouple at position p1 The thermocouple described herein comprises two thermocouple leads, each thermocouple lead including a measuring junction and a cold junction. The thermocouple wires are connected to each other at their measuring ends at the measuring junction, and The cold end is connected to a pair of connecting devices at the cold contact point; II) A temperature sensor, wherein the temperature sensor is configured to measure the temperature at position p1; III) A pair of connecting devices, each connecting device including a cold contact connection end and an opposite end, wherein the cold end of the thermocouple wire is connected at the cold contact to the cold contact connection end of the pair of connecting devices; IV) Processing devices, which are connected to the connecting device at their opposite ends, and a) Configured to process the signals from the thermocouple and the temperature sensor to determine the temperature of the cold junction of the thermocouple wires, and / or b) Configured to process the signals from the thermocouple and the temperature sensor, and to calculate the voltage signal V that the thermocouple will obtain for a cold junction with a cold junction at 0°C and a measuring junction at a temperature T1. 0℃ (T1) is the difference ΔV between the measured voltage signal and the voltage signal.

12. The thermocouple system of claim 11, wherein both connecting devices are made of the same material.

13. The thermocouple system according to claim 11 or 12, wherein at least one of the thermocouple wires comprises tungsten (W) or a noble metal.

14. The thermocouple system according to any one of claims 11 to 13, wherein the thermocouple is a fast thermocouple.

15. A thermocouple device for determining the temperature of a high-temperature environment, the thermocouple device comprising: Thermocouple system according to claims 11 to 14, and V) A moving device configured to move the thermocouple from position p1 to a second position p2. The thermocouple is configured to move from position p1 to the second position p2 in the high-temperature environment; as well as The processing device is configured to determine the temperature of the high-temperature environment by processing the signal from the thermocouple at the second position p2, and a) The temperature of the cold junction at the initial position p1, and / or b) The voltage signal V obtained by a thermocouple with a cold junction at 0°C and a measuring junction at temperature T1. 0℃ (T1) is the difference ΔV between the measured voltage signal V1 and the voltage signal T1.

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