Method for calibrating surface temperature sensing system

Abstract

A method for calibrating a surface temperature sensing system (100), wherein the surface temperature sensing system (100) is configured for determining a surface temperature of a measurement object (130); and wherein the surface temperature sensing system (100) comprises a first surface adapter (120) and a temperature measurement unit (110); and wherein the surface temperature sensing system (100) is configured to be mounted at a measurement object (130) by means of a first surface adapter (120), the method comprising: thermally coupling the temperature measurement unit (110) to a surface of a calibration object (240) by means of a second surface adapter (220); determining a temperature of the surface of the calibration object by means of a temperature measuring unit (110); and determining a calibration value for calibrating the surface temperature sensor (100) based on a comparison of the determined temperature of the surface of the calibration object and a calibration temperature of the surface of the calibration object.

Description

Technical Field

[0001] The present invention generally relates to surface temperature sensing systems for industrial processes. Background Art

[0002] As one of the main control parameters for process control, the determination of temperature is essential for the safe operation of the plant. It is crucial to ensure that the temperature measurement of the process medium is accurate and repeatable.

[0003] In order to determine the temperature of the medium within the container surface, temperature sensors are placed at the surface of the wall of the container in order to measure the temperature of this surface and determine the temperature of the medium at the other side of the wall, respectively. These require regular calibration. Summary of the invention

[0004] The number of non-destructive temperature measurement devices used in industry cannot be ignored. Currently, the calibration of these devices is usually carried out in an oil or water bath or a tube furnace, where the sensing element itself is calibrated. Therefore, the impact of installing these non-destructive temperature measurement devices at the measurement object on the measurement result or measurement uncertainty is ignored. The calibration of temperature sensors can be a major task in the maintenance of industrial equipment, requiring a lot of labor.

[0005] Aspects of the invention relate to a method for calibrating a surface temperature sensing system and a surface temperature sensing system for determining the surface temperature of a measurement object, wherein the subject matter is as described in the independent claims. Advantageous modifications of the invention are stated in the dependent claims. All combinations of at least two of the features disclosed in the description, the claims and the drawings fall within the scope of the invention. In order to avoid repetitions, the features disclosed according to the method shall also apply to the mentioned system and claims may be made according to the proposed system.

[0006] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a method for calibrating a surface temperature sensing system, wherein the surface temperature sensing system is configured for determining a surface temperature of a measurement object, and wherein the surface temperature sensing system comprises a first surface adapter and a temperature measurement unit; and wherein the surface temperature sensing system is configured to be mounted at the measurement object by means of the first surface adapter, the method comprising:

[0007] thermally coupling the temperature measuring unit to the surface of the calibration object by means of a second surface adapter;

[0008] determining the temperature of the surface of the calibration object by means of a temperature measuring unit; and

[0009] A calibration value is determined based on a comparison of the determined temperature of the surface of the calibration object with a calibration temperature of the surface of the calibration object for calibrating the surface temperature sensing system.

[0010] The surface temperature sensing system may be configured to determine the temperature of a measurement point at an outer surface of the measurement object and / or an outer surface of the calibration object. The surface temperature sensing system may include a single sensor element for determining the surface temperature (such as, for example, a resistance temperature detector RTD) or a plurality of sensor elements for determining the surface temperature and / or a sensor element for determining the ambient temperature of the surface temperature sensing system. The surface temperature sensing system may be configured to determine the surface temperature based on a model by means of signals generated by different sensor elements of the surface temperature sensing system.

[0011] The measurement object may be a wall of a container and / or a wall of a pipeline or any other object, in which the surface temperature is to be determined.

[0012] The calibration object may be a portion of a wall of a container and / or a portion of a wall of a pipe or object, which portion is configured to provide at its surface a calibration temperature for calibrating the surface temperature sensing system. The calibration temperature may be a surface temperature of the calibration object that is known in advance and / or determined using other measures.

[0013] The temperature measurement unit may include a single sensor element for determining the surface temperature (such as, for example, a resistance temperature detector RTD) or a plurality of sensor elements for determining the surface temperature and / or a sensor element for determining the ambient temperature. A plurality of sensing elements may be mounted in the temperature measurement unit by means of a structure for fixing the sensing elements. The sensing elements for sensing the respective surface temperature may be placed such that when the surface temperature sensing system and / or the temperature measurement unit is mounted at the respective object by means of the respective surface adapter, the sensing elements for determining the surface temperature are positioned close to the surface of interest.

[0014] The first surface adapter and / or the second surface adapter may include a mounting adapter for mounting the surface temperature sensing system at the measurement object and a neck tube for accommodating and / or mounting the temperature measurement unit to the mounting adapter. If the measurement object is surrounded by a thermal insulation material, the neck tube may improve the assembly and / or disassembly of the surface temperature sensing system.

[0015] According to one aspect, the surface temperature sensing system can be configured to be mounted at the outer surface of the measurement object by means of a first measurement surface adapter. In a further step, the temperature measuring unit of the surface temperature sensing system can be removed from the correspondingly configured surface temperature sensing system and the temperature measuring unit can be mechanically and / or thermally coupled to the outer surface of the calibration object by means of a second surface adapter.

[0016] For calibration, the surface temperature of the calibration object determined by the temperature measuring unit may be compared with a calibration temperature Tcalibration which may be provided in advance, and a calibration value may be determined based on the difference between the determined surface temperature and the calibration temperature.

[0017] Advantageously, by using the described method, the entire unit of the surface temperature sensing system as mounted to the respective object may be taken into account for calibrating the surface temperature sensing system.

[0018] According to one aspect, a temperature measurement unit of a surface temperature sensing system can be placed at a surface of a calibration object for calibration, and a setup for calibrating the surface temperature sensing system can be configured using a similar mounting situation to the measurement object, wherein a second surface adapter is configured to mechanically match and / or thermally match with a first surface adapter to determine a calibration value. The calibration object can be configured to resemble a fluid flow (e.g., delivery) pipe and / or configured as a dry calibrator. The similarity of the mounting situation for calibration can mean that the mechanical condition and / or thermal condition of the temperature measurement unit is similar to the mechanical condition and / or thermal condition of the temperature measurement unit at the measurement object.

[0019] This is because the surface temperature sensing system may determine the surface temperature, wherein the value of the determined surface temperature may depend on the thermal and / or mechanical conditions of the surface temperature sensing system with the surface to be measured.

[0020] The thermal conditions may depend on the mechanical contact of the sensing system with the surface and / or the roughness of the surface, which may be caused by different surface treatments and / or materials of the surface to be measured and / or coatings of the surface to be measured and / or corrosion conditions of the surface to be measured and / or surface curvature of the surface to be measured.

[0021] Taking the above mentioned dependencies into account it should be appreciated that merely calibrating the temperature sensor element of the surface temperature sensing system by at least partially inserting the surface temperature sensing system into an oil bath is not sufficient to accurately calibrate the surface temperature sensing system for determining the surface temperature of the measurement object.

[0022] In this case, the sensing element of the surface temperature sensing system is calibrated, for example, in a water bath. This 'classic' calibration method may produce significant deviations in the determined surface temperature compared to the measurement situation at the measuring point, where the surface temperature sensing system or the temperature measuring unit is not surrounded by a fluid with the temperature of interest, including in close thermal contact with the corresponding temperature sensor element.

[0023] Such calibration tests can only take into account the individual sensor elements and not the overall measurement system including the various thermal couplings, in particular, the thermal couplings to the surface of interest.

[0024] Advantageously, the described calibration method can take into account certain root causes of erroneous determination of surface temperature as mentioned above, where in particular some properties of the thermal condition may drift over time, as opposed to the case if the surface temperature sensing system was calibrated using only a liquid bath or fluid environment.

[0025] By using the described method for calibrating a surface temperature sensing system, mechanical and thermal conditions similar to process conditions can be designed, wherein the surface temperature sensing system is coupled to a measurement object. Such a calibration method can increase the robustness of determining the surface temperature using the surface temperature sensing system, since it can compensate for manufacturing tolerances and / or installation errors and / or errors caused by a specific model to determine the surface temperature using the signal of a sensor element of the surface temperature sensing system.

[0026] Also advantageously, by using the described calibration method, the calibration method may reveal problems with thermal coupling of the surface temperature sensing system to the measurement object (particularly in a manufacturing environment) and / or may reveal changes in thermal coupling over time during production use of the surface temperature sensing system.

[0027] The described calibration method can address multiple error sources to be compensated, including mounting resistance and thermal resistance of the internal thermal path of the surface temperature sensing system, and the calibration method can be adapted to the individual circumstances of the surface of interest. Thus, the calibration provided by the method reduces the uncertainty in determining the process medium temperature.

[0028] The described calibration bath procedure may cause problems for all types of surface temperature sensing systems, even if they include more than one temperature sensitive sensor and / or whether they are model-based. Model-based surface temperature sensing systems can determine the temperature of the surface of interest by extrapolation based on the sensor signals.

[0029] Using the calibration method as described in the present specification, the device-specific thermal behavior of the installed surface temperature sensing system can be taken into account during calibration, and the output signal of the surface temperature sensing system can be calibrated according to the well-known calibration temperature of the calibration object, because the similarity of the installation and the similar error sources caused by it are taken into account.

[0030] Advantageously, because the first surface adapter can remain at the measurement object during the calibration process, the surface temperature sensing system is configured for non-destructive detachable assembly and / or disassembly of the temperature measurement unit and the first surface adapter, so that the temperature measurement unit can be calibrated with less work.

[0031] The method enables and may include providing services to industrial users of temperature measurement equipment. The services provided can most effectively save labor for industrial users. The services may include checking the measurement points at the industrial site and / or receiving relevant parameters for performing the method from the industrial user. The acquired knowledge about the situation may be used to perform a calibration method in the calibration method described below. This specifically relates to the parameters of the method described below, and includes all or a subset of relevant parameters that physically affect the mechanical and thermal coupling of the non-destructive sensor to the surface and process.

[0032] The service may also include performing calibration methods via various equipment, for example, on-site at the industrial user (e.g., close to the measurement location) or at the operating facility (e.g., in a laboratory at the customer's location) or remotely (e.g., in a service provider's laboratory).

[0033] According to an aspect, the thermal state of the contact of the temperature measurement unit with the surface of the calibration object corresponds to the thermal state of the contact of the temperature measurement unit with the surface of the measurement object.

[0034] The thermal state may describe the overall thermal state of the temperature measurement unit relative to the temperature field of the entire environment (including the temperature of the surface to be determined and the associated field of the heat flow of the entire environment of the temperature measurement unit).

[0035] In other words, with respect to determining the temperature of the surface of the calibration object, the conditions of the environment regarding the temperature measurement unit during calibration may be identical to the conditions of the environment during determining the surface temperature of the measurement object.

[0036] According to one aspect, the thermal state of the contact of the temperature measuring unit with the surface of the measurement object and / or the thermal state of the contact of the temperature measuring unit with the surface of the calibration object is characterized by a corresponding structure of the surface of the calibration object and / or a corresponding structure of the surface of the measurement object.

[0037] This may mean that the thermal state takes the entire structure of the arrangement for determining the surface temperature of the measurement object and / or calibration object into account, in particular since the thermal state of the contact of the temperature measuring unit with the surface of the measurement object or calibration object may influence the value of the corresponding surface temperature determined by the surface temperature sensing system.

[0038] According to one aspect, the structure of the surface of the calibration object and / or the structure of the surface of the measurement object is characterized by a respective surface curvature and / or a respective material of the surface and / or a respective roughness of the surface and / or a respective coating of the surface and / or a respective corrosion condition of the surface.

[0039] The structure of the surface may influence the thermal conditions of the contact of the temperature measurement unit with the surface of the measurement object or calibration object and the structure of the surface may influence the value of the corresponding surface temperature determined by the surface temperature sensing system.

[0040] According to one aspect, the calibration object is a voluminous calibration element and / or a calibration container wall and / or a calibration wall of a calibration tube.

[0041] As understood herein, the term container may include any wall separating the medium from the environment, such as, for example, a pipe, a conduit or a tank or a vessel, etc. The calibration container wall may include a portion of the container. The calibration wall of the calibration tube may be a portion of the tube. The temperature of the larger calibration element and / or the calibration container wall and / or the calibration wall of the calibration tube may be controlled by a heating element, and the heat may be transferred to the surface by means of a fluid (e.g., water, oil or gas).

[0042] According to one aspect, the second surface adapter is configured to mechanically mate and / or thermally mate with the first surface adapter.Alternatively or additionally, the second surface adapter is identical to the first surface adapter.

[0043] If the first surface adapter is identical to the second surface adapter, the entire surface temperature sensing system is removed from the measurement object and mounted on the calibration object to perform the method for calibrating the surface temperature sensing system.

[0044] If the conditions for measuring the surface temperatures at the respective objects are consistent so that the temperature values ​​obtained by determining the respective surface temperatures are the same within a certain temperature range, then the first surface adapter is thermally matched with the second surface adapter. Preferably, the temperature range for actual matching is within a range of 5 degrees Celsius. More preferably, the temperature boundary is within a range of 2 degrees Celsius. Even more preferably, the temperature boundary is within a range of 1 degree Celsius.

[0045] Additionally, the thermal condition of the environment of the second surface adapter during calibration can be configured to be comparable to the environment of the first surface adapter at the measurement object. The thermal condition of the environment during calibration and the thermal condition of the first surface adapter at the measurement object can be comparable as follows: the surface temperature of the measurement object and the calibration object to be determined are respectively comparable to the difference between the corresponding ambient temperature. The comparable difference between the surface temperature of the corresponding object to be determined and the corresponding ambient temperature can be within a range of 70 degrees Celsius. More preferably, the temperature range is within a range of 20 degrees Celsius. Even more preferably, the temperature range is within a range of 10 degrees Celsius.

[0046] If the first surface adapter and the second surface adapter are both designed and configured in the same manner, then the two adapters (including the neck tube and / or the mounting adapter) are mechanically matched.

[0047] According to one aspect, the surface temperature sensing system is configured for non-destructive detachable assembly and / or disassembly of the temperature measurement unit and the first surface adapter.

[0048] The first surface adapter and the temperature measuring unit of the surface temperature sensing system may be detachably connected, for example, by a threaded fitting.

[0049] This enables a quick and safe removal of the temperature measurement unit for calibration. In particular, since the entire first surface adapter can remain at the measurement object, this is more advantageous if the surface of the measurement object is thermally insulated, since the insulation does not need to be removed for removal of the temperature measurement unit. In particular, if the first surface adapter comprises a neck tube, the neck tube extends above the insulation. The second surface adapter may be configured for non-destructive detachable assembly and / or disassembly of the temperature measurement unit and the second surface adapter of the surface temperature sensing system.

[0050] According to one aspect, when mounted to the calibration object by means of the second surface adapter, the temperature measurement unit is mechanically coupled to the surface of the calibration container wall with a calibration contact pressure. The calibration contact pressure may correspond to a measurement contact pressure of the temperature measurement unit with the surface of the measurement object when the temperature measurement unit is mounted to the measurement object by means of the first surface adapter.

[0051] The thermal state of the contact of the temperature measuring unit with the corresponding surface is characterized by a contact pressure. A corresponding contact pressure can be provided if a similar contact force is applied between the temperature measuring unit and the corresponding surface during calibration, for example by using a corresponding surface adapter of substantially the same design as in the application during calibration.

[0052] According to one aspect, the surface temperature of the calibration object corresponds to the surface temperature of the measurement object, and / or the calibration environment temperature corresponds to the measurement environment temperature, and / or the thermal insulation of the calibration object corresponds to the thermal insulation of the measurement object.

[0053] The thermal condition of the contact of the temperature measuring unit with the surface of the measurement object and / or calibration object is characterized by the object surface temperature and / or the ambient temperature and / or the thermal insulation of the respective object.

[0054] The temperature range corresponding to the object surface temperature and / or the ambient temperature may be one degree Celsius. Preferably, the temperature range is a difference of 5 degrees Celsius. More preferably, the temperature range is a difference of 2 degrees Celsius. Even more preferably, the temperature range is a difference of 1 degree Celsius.

[0055] As for the measurement object, the corresponding thermal insulation can have the same thickness and structure as the calibration object, in particular with regard to the thermal conditions.

[0056] According to one aspect, a calibration method comprises:

[0057] The temperature measuring unit is immersed in a liquid having a liquid calibration temperature. Additionally or alternatively, the calibration value is additionally based on a comparison of the determined liquid temperature and the liquid calibration temperature determined by the temperature measuring unit. Preferably, the temperature measuring unit is partially immersed in the liquid, wherein the portion of the temperature measuring unit immersed in the liquid comprises a temperature sensor element of the temperature measuring unit.

[0058] This additional step of the calibration method can identify root causes of deviations of the determined temperature of the surface of the calibration object from the calibration temperature, preferably by evaluating a temperature signal of a sensor element of the temperature measuring unit in comparison with the determined temperature of the surface of the calibration object.

[0059] According to one aspect, a temperature measurement unit includes a contact sensor and a reference sensor, wherein the temperature measurement unit is configured such that the contact sensor is thermally coupled closer to a surface of a measurement object and / or thermally coupled closer to a surface of a calibration object than the reference sensor when the contact sensor is respectively mounted, and the temperature of the calibration object is determined based on a temperature value determined using the contact sensor and a temperature value using the reference sensor.

[0060] According to one aspect, the calibration value includes a calibrated ratio of a temperature value generated by the reference sensor and a pressure value generated by the contact sensor.

[0061] Because a fault condition (such as, for example, water in the surface adapter) may change the calibration ratio, determining the calibration ratio may detect a fault condition of the surface temperature sensing system when determining the surface temperature. The temperature value of the reference sensor and / or the contact sensor may be a signal generated by the respective sensor.

[0062] According to one aspect, the calibration value is based on a comparison of a calibration ratio and a measurement ratio, wherein the measurement ratio is defined by a temperature value generated by a reference sensor and a temperature value generated by a contact sensor of a temperature measuring unit coupled to the surface of the measurement object by means of a first surface adapter; and wherein preferably, the measurement ratio is predetermined in a step of a calibration method of a surface temperature sensing system, as described above.

[0063] Because a fault condition (such as, for example, water within the first surface adapter) may change the calibration ratio, when determining the surface temperature at the measurement object, a comparison of the calibration ratio and the measured ratio may detect a fault condition of the surface temperature sensing system and / or recalibrate the surface temperature sensing system.

[0064] According to one aspect, when performing one of the calibration methods as described above, the calibration method may be performed at a manufacturing site using a signal coupling member of a surface temperature sensing system close to a measurement object.

[0065] This means that thermal coupling of the temperature measuring unit of the surface temperature sensing system to the surface of the calibration object by means of the second surface adapter can be performed close to the measurement object, so that the signal coupling component can be used during a calibration method for determining the temperature of the surface of the calibration object and / or a temperature determination component for signal coupling of the temperature measuring unit of the surface temperature sensing system at the manufacturing site.

[0066] A method for calibrating a surface temperature sensing system (100), wherein

[0067] The surface temperature sensing system (100) is configured to determine the surface temperature of a measurement object (130); and

[0068] The surface temperature sensing system (100) comprises a first surface adapter (120) and a temperature measuring unit (110); and

[0069] The surface temperature sensing system (100) is configured to be installed at a measurement object (130) by means of a first surface adapter (120), and the method comprises:

[0070] thermally coupling the temperature measurement unit (110) to the surface of the calibration object (240) by means of a second surface adapter (220);

[0071] determining the temperature of the surface of the calibration object by means of a temperature measuring unit (110); and

[0072] A calibration value is determined based on a comparison of the determined temperature of the surface of the calibration object with a calibration temperature of the surface of the calibration object for calibrating the surface temperature sensing system (100).

[0073] A surface temperature sensing system for determining the surface temperature of a measurement object is proposed. The surface temperature sensing system comprises:

[0074] A temperature measuring unit and a first surface adapter, wherein the surface temperature sensing system is configured for non-destructive disassembly of the temperature measuring unit and the first surface adapter. The surface temperature sensing system can be configured to be calibrated according to any one of claims 1 to 13 by means of a second surface adapter, the second surface adapter being configured to mechanically match and / or thermally match the first surface adapter.

[0075] According to one aspect, the surface temperature sensing system is configured for non-destructive detachable assembly and / or disassembly of the temperature measurement unit and the first surface adapter.

[0076] According to one aspect, the first surface adapter is identical to the second surface adapter.

[0077] According to one aspect, a temperature measurement unit of a surface temperature sensing system comprises a contact sensor and a reference sensor. The temperature measurement unit of the surface temperature sensing system is configured such that the contact sensor is thermally coupled to a surface of a measurement object and / or a calibration object more closely than the reference sensor when they are respectively mounted. The surface temperature of the measurement object and / or the surface temperature of the calibration object is determined based on a temperature signal measured by the contact sensor and a temperature signal measured by the reference sensor.

[0078] This means that the surface temperature sensing system may include at least one sensing element for determining the surface temperature of the respective object. The surface temperature sensing system may be configured to determine and / or estimate the temperature of the surface of the respective object, in particular based on temperature signals generated by a plurality of sensor elements. The described calibration method may be used to calibrate a plurality of sensor elements.

[0079] As described above, a method for determining the temperature of a measurement point on the outer surface of a measurement object using a surface temperature sensing system is proposed. Preferably, the surface temperature sensing system can be used to perform the calibration described above.

[0080] A calibration system is proposed, comprising a plurality of calibration objects, wherein each calibration object is configured to provide a calibration surface, and wherein each calibration object is configured to provide a calibration temperature at its surface suitable for calibration.

[0081] The calibration temperature is suitable for calibration if the surface temperature is defined to be within 1° C. The calibration system may be a calibration fixture.

[0082] According to one aspect, a calibration system may include a plurality of second surface adapters configured to perform the calibration method as described above.

[0083] According to one aspect, each second surface adapter of the plurality of second surface adapters may include a neck tube for mounting a temperature measurement unit for calibration as described above.

[0084] According to one aspect, the calibration system may comprise a water circulation arrangement for tempering the surface of the calibration object.

[0085] The calibration system water calibration can be a system configured to permanently provide a plurality of calibration objects with a plurality of thermal states as described above. The plurality of calibration objects can be selected according to frequently used calibration objects, which can preferably provide different surface structures according to the measurement objects of typical applications, in particular surface structures with different surface curvatures and / or different materials and / or thicknesses.

[0086] Advantageously, the calibration system may provide a plurality of calibration objects such that rearrangement of the calibration objects (eg, pipe surfaces) is no longer required.

[0087] The temperature measurement unit may include a standard insert rod made of a known material to enclose the sensing element. Using such a rod ensures that one side of the thermal contact used to define the thermal contact resistance is always well known and defined. This removes uncertainty and variation from the application case, thus facilitating improved accuracy. This is because the thermal resistance depends on, for example, the contact pressure, the size of the contact surface, the surface structure, the surface roughness and / or the material of the surface to be measured.

[0088] The material of the insert rod may be, for example, stainless steel or copper or silver, or a combination thereof.

[0089] If the surface where the temperature is to be measured comprises a specific material, preferably the calibration equipment comprises a test surface made of the same material.An adapter set or a tube set in the calibration fixture may be used.

[0090] Advantageously, when compared to temperature determination using thermowells, the non-destructive measurement method makes it very easy to essentially reproduce the measurement point situation in a simple calibration setup, where the complexity of the geometry and the wide variety of application designs preclude calibration using a similar approach.

[0091] According to one aspect, the calibration system can be configured to be provided by thermal insulation during calibration, wherein in particular the thermal insulation can be matched to the thermal insulation of the measurement object.

[0092] Surface temperature sensing systems may be used to determine the temperature of a process fluid within a vessel without penetrating the process vessel wall at the surface of the vessel wall.

[0093] The surface temperature sensing system may include a temperature measurement unit and a first surface adapter or a second surface adapter to position the temperature measurement unit on an external surface of a measurement object, such as, for example, a container wall. As the temperature of the process fluid changes, the temperature of the container wall may also change. The container wall temperature may also change in response to changes in environmental conditions, such as sunlight, wind, or rain. The insulation of the surface temperature sensing system may shield the external surface and / or the surface temperature sensing system to a certain extent from changes in environmental conditions. However, to the extent that the insulation is not ideal, the accuracy of the non-destructive process temperature measurement may be affected. In order to improve the surface temperature measurement using the surface temperature sensing system, the surface temperature sensing system may include an ambient temperature measurement sensor and a reference temperature sensor, which is in at least slightly different thermal contact with the surface and the surface temperature measurement sensor. The temperature measurement sensor typically has the following characteristics: it has a stronger thermal coupling to the surface than one or more reference temperature sensors, which means that the thermal resistance is lower.

[0094] The tip of the surface temperature sensing system may directly contact the surface of the measurement object, such as the surface of a pipe and / or a container wall, whose surface temperature is to be determined. Advantageously, the heat transfer resistance from the surface of the surface temperature sensing system to the tip of the thermometer rod may be reduced by the surface pressure generated at the measurement tip. This may be achieved, for example, by a spring-loaded mechanism and / or a screw mechanism and / or any mechanism of the surface temperature sensing system that is configured to apply a consistent pressure.

[0095] The temperature measurement sensor differs from the reference temperature sensor in that its sensing element has a stronger thermal coupling to the surface, which means a lower thermal resistance, than the reference temperature sensor or sensors.

[0096] In detail, at least one temperature measuring sensor is connected to a first measuring location on the outer surface of the measurement object via a coupling having good thermal conductivity characterized by a thermal resistance R0.

[0097] A temperature measuring sensor may have a well-defined thermal resistance Ru to the environment, characterized by the ambient temperature.

[0098] Advantageously, the respective reference temperature sensor may have a well-defined thermal resistance R0_ref to the second measuring location at the surface of the container and a well-defined thermal resistance Ru_ref to the environment, characterized by the temperature of the environment. In the case of a standard thermometer stem, this thermal resistance is approximately proportional to the length of the stem between the respective temperature measuring location of the reference temperature sensor and the environment, such as, for example, the environment at the location of the electronics housing.

[0099] The thermal resistance Ru and / or Ru_ref also includes the conduction resistance, convection resistance and radiation resistance between the outer surface of the standard thermometer stem and / or neck tube and the ambient air.

[0100] This means that the reference temperature sensor may be thermally coupled to the surface of the container wall such that the thermal resistance between the reference temperature sensor and the surface of the container wall is higher than the thermal resistance between the measuring temperature sensor and the surface of the container wall at their respective locations.

[0101] The temperature measurement sensor may be coupled to a surface of the measurement object, characterized by a thermal resistance R0 that is smaller than a thermal resistance R0_ref between the surface of the container wall and a reference temperature sensor.

[0102] In particular, R0_ref≠R0 and / or Ru_ref≠Ru and / or the ratio of the thermal resistance of the reference sensor to the environment or surface, Ru_ref / R0_ref, is chosen slightly different from Ru / R0 mentioned above: Ru_ref / R0_ref≠Ru / R0.

[0103] in this case:

[0104] R1 = R0_ref - R0 and R2 = Ru_ref

[0105] can be defined and compensated in the same way as suggested in WO2019 / 063519.

[0106] Advantageous ratios of R2 / R1 may be 100, 50, 10 or 2, for example.

[0107] According to one aspect, a temperature sensor assembly includes a plurality of temperature measurement sensors and / or a plurality of reference temperature sensors.

[0108] The surface temperature can be determined by the following formula:

[0109] T_surface=T1+a(T1-T2)+b(T2-T_amb)+cT1+dT2+eT_amb+f(T1,T2,T_amb)

[0110] Wherein a, b, c, d, e are constants to be defined by calibration, wherein each of the constants can be determined to be 0. The relation f(T1, T2, Tamb) can be a freely definable (eg non-linear) function which can be determined to be zero.

[0111] T1 is a temperature value determined by using a temperature measuring sensor, T2 is a temperature value determined by using a reference temperature sensor, and Tamb is an ambient temperature value.

[0112] To determine the temperature of the medium inside the container using the non-destructive temperature sensor assembly, a model-based calculation may be used based on the temperature readings determined using the temperature sensor assembly to accurately determine the surface temperature of the surface of the container wall.

[0113] The medium may be any fluid, including liquids and / or gases and / or bulk materials or any mixture of these (eg aerosols and multiphase flows).

[0114] Model-based calculations may be performed by a software tool that determines the media temperature based on the outer surface temperature of the vessel wall determined by the non-destructive temperature sensor assembly.

[0115] The temperature can be determined according to the method disclosed in patent application WO2019063519A1.

[0116] According to one aspect, the reference temperature sensor is coupled to the surface of the wall of the container via a spatial gap and / or via a second member for thermally coupling the reference sensor to the surface of the wall of the container, the second member comprising a low thermal conductivity material for thermally decoupling the reference temperature sensor from at least part of the surface of the wall of the container, and wherein the second member is located between the reference temperature sensor and the surface of the wall of the container.

[0117] This spatial gap makes it possible to couple the reference temperature sensor to the surface of the wall of the container without mechanical contact, so as to define a contact thermal resistance R0_ref.

[0118] According to one aspect, the temperature measurement sensor and / or the reference temperature sensor comprises a resistance thermometer and / or a thermocouple.

[0119] Such a resistance thermometer may be a PTC thermistor and / or a PTC resistor. Additionally or alternatively, the temperature measurement sensor and / or the reference temperature sensor may comprise any means for determining the temperature of the surface of the container. BRIEF DESCRIPTION OF THE DRAWINGS

[0120] The accompanying drawings illustrate embodiments of the present invention and, together with the specification, are used to explain the principles of the present invention. These drawings are included to further understand the present invention, and these drawings have been incorporated into this application and constitute a part of this application. These drawings show:

[0121] Figure 1 is a schematic sketch of a surface temperature sensing system thermally coupled to a surface of a measurement object;

[0122] Figure 2 is a schematic sketch of a temperature measuring unit thermally coupled to a surface of a calibration object;

[0123] Figure 3 is a schematic sketch of another surface temperature sensing system thermally coupled to a surface of a measurement object;

[0124] Figure 4 is a schematic sketch of another temperature measurement unit thermally coupled to a surface of a calibration object;

[0125] Figure 5 is a schematic sketch of the mounting adapter. DETAILED DESCRIPTION

[0126] Figure 1 Schematically depicted is a surface temperature sensing system 100 for determining the surface temperature of a measurement object, which is thermally coupled to the surface of a measurement object 130, which in this example is a pipe or a container drawn as a cross section. The measurement object 130 is thermally insulated by an insulation layer 140.

[0127] The surface temperature sensing system 100 is mounted to and thermally coupled to a measurement object 130 by means of its first surface adapter 120, which includes a neck tube 122 and a mounting adapter 125. The temperature measurement unit 110 may include an insertion rod and a housing, the housing including a temperature determination circuit system. The insertion rod may include a plurality of sensor elements, the plurality of sensor element signals being thermally coupled to the temperature determination circuit system. In order to perform non-destructive disassembly of the temperature measurement unit 110 with the first surface adapter 120, the temperature measurement unit 10 may be coupled to the surface adapter 120 by a mechanical joint.

[0128] Figure 2 The temperature measurement unit 110 of the surface temperature sensing system 100 is schematically depicted, which is mechanically and / or thermally coupled to the surface of a calibration object 240 via a second surface adapter 220 for calibrating the surface temperature sensing system 100. The calibration object 240 may be tempered by a thermostat unit to provide a calibration temperature at its surface, which Figure 2 The surface of the calibration object 240 may be provided by a surface curvature that matches the curvature of the measurement object 130, such as Figure 1 The calibration object 130 may be thermally insulated by a thermal insulation layer 240 to match the thermal insulation of the measurement object.

[0129] The second surface adapter 220 may include a neck tube 222 and a mounting adapter 225. The temperature measurement unit 110 may include an insertion rod and a housing including a temperature determination circuit system. The insertion rod may include a plurality of sensor elements that are signal coupled to the temperature determination circuit system. The temperature measurement unit 110 may be configured to be mechanically coupled to the second surface adapter 224 for non-destructive assembly and disassembly, such as by a mechanical joint.

[0130] Figure 3 A surface temperature sensing system is schematically depicted, which is mechanically and / or thermally coupled to the surface of a measurement object 330 via a first surface adapter 300. The surface temperature sensing system 300 corresponds entirely to Figure 1 The surface temperature sensing system 100 is provided without the neck tube of the second surface adapter.

[0131] Figure 4 A temperature measuring unit of a surface temperature sensing system 300 is schematically depicted, which is mechanically and / or thermally coupled to a surface of a calibration object 430 via a second surface adapter 400, wherein the calibration object 430 is thermally insulated by an insulating layer 440. The calibration of the temperature measuring unit 400 corresponds entirely to Figure 2The temperature measuring unit 110 is calibrated without the neck tube of the second surface adapter.

[0132] Figure 5 Schematically depicted is a mounting adapter 500 which may be mechanically coupled to a measurement object and / or calibration object.By means of a contact surface 512, the surface adapter 500 may be aligned with a curved surface of a measurement object and / or calibration object. Figure 5 The neck tube shown in FIG. 5 can be mechanically coupled to the surface adapter 500 via the socket 510. The temperature measuring unit can be guided by the neck tube and mechanically and / or thermally coupled to the surface of the measurement object and / or calibration object by passing through the hole 520.

Claims

1. A method for calibrating a surface temperature sensing system (100), wherein The surface temperature sensing system (100) is configured to determine the surface temperature of a measurement object (130); as well as The surface temperature sensing system (100) comprises a first surface adapter (120) and a temperature measuring unit (110); and The surface temperature sensing system (100) is configured to be installed at the measurement object (130) by means of the first surface adapter (120), and the method comprises: thermally coupling the temperature measurement unit (110) to a surface of a calibration object (240) by means of a second surface adapter (220); determining the temperature of the surface of the calibration object by means of the temperature measuring unit (110); and A calibration value is determined based on a comparison of the determined temperature of the surface of the calibration object with a calibration temperature of the surface of the calibration object for calibrating the surface temperature sensing system (100).

2. The method according to claim 1, wherein a thermal state of contact of the temperature measurement unit (110) with the surface of the calibration object corresponds to a thermal state of contact of the temperature measurement unit (110) with the surface of the measurement object.

3. The method according to claim 2, wherein the thermal state of the contact between the temperature measuring unit (110) and the surface of the measurement object and / or the thermal state of the contact between the temperature measuring unit (110) and the surface of the calibration object is characterized by a corresponding structure of the surface of the calibration object and / or a corresponding structure of the surface of the measurement object.

4. The method according to claim 3, wherein the structure of the surface of the calibration object and / or the structure of the surface of the measurement object is characterized by a corresponding surface curvature and / or a corresponding material of the surface and / or a corresponding roughness of the surface and / or a corresponding coating of the surface and / or a corresponding corrosion condition of the surface.

5. The method according to any of the preceding claims, wherein the calibration object (240) is a bulky calibration element and / or a calibration container wall.

6. The method according to any of the preceding claims, wherein the second surface adapter (220) is configured to mechanically match and / or thermally match the first surface adapter (120); and / or the second surface adapter (220) is identical to the first surface adapter (120).

7. The method according to any of the preceding claims, wherein the surface temperature sensing system (100) is configured for non-destructively detachably assembling the temperature measurement unit (110) to the first surface adapter (120) and / or non-destructively disassembling the temperature measurement unit (110) from the first surface adapter (120).

8. A method according to any of the preceding claims, wherein the temperature measuring unit (110) is mechanically coupled to the surface of the calibration container wall with a calibration contact pressure when mounted to the calibration object (240) by means of the second surface adapter (220); and wherein the calibration contact pressure corresponds to the measured contact pressure of the temperature measuring unit (110) with the surface of the measurement object when mounted to the measurement object (240) by means of the first surface adapter (120).

9. A method according to any one of the preceding claims, wherein the surface temperature of the calibration object (240) corresponds to the surface temperature of the measurement object (140), and / or the calibration environment temperature corresponds to the measurement environment temperature, and / or the thermal insulation of the calibration object corresponds to the thermal insulation of the measurement object.

10. A method according to any one of the preceding claims, comprising: The temperature measuring unit (110) is immersed in a liquid, the liquid having a liquid calibration temperature; and / or wherein the calibration value is additionally based on a comparison of the determined liquid temperature with the liquid calibration temperature determined by the temperature measuring unit (110).

11. The method according to any one of the preceding claims, wherein the temperature measurement unit (110) comprises a contact sensor and a reference sensor, wherein the temperature measurement unit is configured such that, when respectively mounted, the contact sensor is thermally coupled closer to the surface of the measurement object (140) and / or is thermally coupled closer to the surface of the calibration object (240) than the reference sensor; and the temperature of the calibration object (240) is determined based on a temperature value determined using the contact sensor and a temperature value using the reference sensor. 12 . The method of claim 11 , wherein the calibration value comprises a calibrated ratio of the temperature value generated by the reference sensor to the temperature value generated by the contact sensor.

13. The method according to claim 12, wherein the calibration value is based on a comparison of the calibration ratio and a measurement ratio, wherein the measurement ratio is defined by a temperature value generated by the reference sensor and a temperature value generated by the contact sensor of the temperature measuring unit coupled to the surface of the measurement object by means of the first surface adapter (120); and wherein preferably, the measurement ratio is determined before the steps of the method for calibrating the surface temperature sensing system according to any one of claims 1 to 12.

14. A surface temperature sensing system (100) for determining a surface temperature of a measurement object (140); The surface temperature sensing system comprises: A temperature measuring unit (110); as well as A first surface adapter (120), wherein the surface temperature sensing system (100) is configured to perform non-destructive disassembly of the temperature measurement unit (110) and the first surface adapter; and The surface temperature sensing system is configured to sense the temperature of the surface using a second surface adapter. (220) Calibrated according to any one of claims 1 to 13, the second surface adapter (220) being configured to mechanically match and / or thermally match the first surface adapter (120).

15. The surface temperature sensing system (100) according to claim 14, comprising: Contact sensor; as well as a reference sensor; and wherein the temperature measuring unit is configured such that, when respectively mounted, the contact sensor is thermally coupled closer to the surface of the measurement object and / or the calibration object than the reference sensor; and wherein the surface temperature of the measurement object (140) and / or the surface temperature of the calibration object (240) is determined based on a temperature signal measured by the contact sensor and a temperature signal measured by the reference sensor.

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