Control of a calibration system

Abstract

The present invention relates to a system for calibrating a temperature sensor. The system comprises a graphical user interface, GUI, and a processor functionally linked to temperature the temperature sensors to receive sensor readouts representing actual measured temperatures, and control display information on the GUI.

Description

[0001] 85705PC01

[0002] 1

[0003] CONTROL OF A CALIBRATION SYSTEM

[0004] FIELD OF THE INVENTION

[0005] The present invention relates to a system for calibrating a temperature sensor. The system comprises a graphical user interface, GUI, and a processor functionally linked to temperature the temperature sensors to receive sensor readouts representing actual measured temperatures, and control display information on the GUI.

[0006] BACKGROUND OF THE INVENTION

[0007] Calibration of temperature sensors is a delicate matter requiring controlling a temperature of a sensor to be calibrated and relating the temperature measured by the sensor with a temperature sensor assigned to provide true temperature measures.

[0008] A temperature calibration process typically involves a set temperature at which the temperature is to be calibrated. While it may be tempting to provide a calibration process unsupervised by a human, supervision of the calibration process has the potential to observe whether the calibration process is carried out according to a specific standard operation procedure or not.

[0009] Data produced during a calibration process typically comprises a set of temperature measurements as function of time. Each temperature measurement may have meta data comprising time at which the measurement is made, and by which sensor, such true sensor or sensors to be calibrated.

[0010] A human needs to be highly trained and specialized to observe whether such a "stream" of temperatures reflects a calibration process according to a standing operating procedure or not. In addition to this, the calibration process is to be ended at some point in time, and it may be critical to end a calibration process premature or long time after the calibration can be said to have been concluded. A premature ending of a calibration process often results in a less accurate calibration, and extending a calibration process after the calibration should have been concluded results in less effective use of the calibration device used for calibration.85705PC01

[0011] 2

[0012] In addition, calibration of a temperature sensor often requires that the sensor is placed in the calibration device in a careful manner e.g. to avoid misplacement, automatic initiation of a calibration process triggered by arranging a sensor in calibration device may introduce error sources as there is no guarantee that the sensor is correctly placed in the calibration device.

[0013] Hence, improved human interaction with a calibration device to control a calibration process of temperature sensor would be advantageous, and in particular a more efficient and / or reliable human interaction with the calibration device would be advantageous.

[0014] OBJECT OF THE INVENTION

[0015] It is an object of the invention to provide a human interaction with a calibration device to control a calibration process of temperature sensor.

[0016] It is a further object of the present invention to provide an alternative to the prior art.

[0017] SUMMARY OF THE INVENTION

[0018] Thus, the above described object and several other objects are intended to be obtained in a first aspect of the invention by providing a system for calibrating a temperature sensor, comprising:

[0019] a temperature-controlled receptacle configured for receiving said temperature sensor and to control the temperature of said receptacle at least up to a set temperature;

[0020] at least one reference temperature sensor arranged to measure a temperature inside said temperature-controlled receptacle;

[0021] a graphical user interface, GUI,

[0022] a processor functionally linked to

[0023] • said temperature sensors to receive sensor readouts representing actual measured temperatures by said temperature sensors, and

[0024] • control display information on the GUI;

[0025] and is configured to automatically toggle from a first screen to a second screen in said GUI, wherein85705PC01

[0026] 3

[0027] o said first screen including absolute temperature courses measured by each of said temperature sensors, said temperature courses are displayed together with said set temperature;

[0028] o said second screen including temperature courses measured by each of said sensors timewise after said second screen has been toggled wherein said processor is configured

[0029] to display a start-up screen requiring a user to provide to said processor an input to initiate a calibration process of said temperature sensor, and to initiate a calibration process of said temperature sensor after said input has been provided by said user.

[0030] A calibration process according to the invention is typically carried out by the controller controlling inter alia the temperature in the temperature-controlled receptacle, where the temperature gradually reaches a calibration temperature. In order to allow for a user to verify that the calibration process proceeds in a prosperous way towards calibration of a temperature sensor, the present invention shows the result of the calibration process in screens of the GUI, such as a first and a second screen.

[0031] A calibration process according to the invention can be seen as proceeding in two-stages, where a first stage relates to increasing the temperature in the temperature-controlled receptacle to the desired temperature, and a second stages relates to obtaining a thermal equilibrium between the sensors and the temperature-controlled receptacle.

[0032] In order to provide a fast calibration process, thermal equilibrium is typically not aimed at during the first stage, and it is therefore important that the user in particular during the first stage can follow the temperature course approaching the calibration temperatures. For instance, if the user based on the displayed information concludes that the temperatures do not approach the calibration temperature in an asymptotic manner, the user can cancel an ongoing calibration process, and restart a new calibration process after for instance the system for calibration has been inspected.85705PC01

[0033] 4

[0034] In the second stage, thermal equilibrium shows-up as the temperature measured by the sensor is substantially constant over time, whereas thermal nonequilibrium will show-up as e.g. a sinusoidal temperature course or temperature changes asymptotic reaching equilibrium. Hence, also in the second stage, the user can evaluate the calibration process and cancel an ongoing calibration process and restart a new calibration process after for instance the system has been inspected and / or calibration settings have changed. As an alternative to cancel the calibration, the user might wait until the desired equilibrium is reached before the calibration is carried out.

[0035] In preferred embodiments, the first screen displays absolute temperature courses during temperature going towards the calibration temperature. As the screen display absolute temperature courses a user can follow the calibration and has the possibility to intervene, such as ending the calibration process, in case the absolute temperature does not proceed as expected. This could for instance be the case, where a wrong calibration temperature has been input, some malfunction of the temperature control has occurred,

[0036] The first screen will also allow the user to estimate when the calibration temperature will be achieved which will allow the user to perform other tasks while waiting.

[0037] In preferred embodiments, the system for calibration toggles to the second screen as the calibration process proceeds, which second screen may provide the user with information relating to evaluate whether or not a calibration can be correctly carried out by the system.

[0038] Hence, the system for calibration can be seen as providing a supervised calibration, such as a supervised manually or automated calibration.

[0039] As disclosed herein, the processor may be configured to carry out the calibration process and calibrate the sensor to be calibrated. However, such an automated calibration can in preferred embodiments be cancelled by a user.85705PC01

[0040] 5

[0041] Temperature sensor as used herein refers to a sensor providing a readout representing an actual measured temperature by the sensor, wherein the readout is an electrical signal or and electrical detectable signal, such as a change in ohmic resistance.

[0042] Calibration process as used herein refers to a multi-step process for assigning actual temperature to a temperature sensor to be calibrated.

[0043] Calibration as used herein refers to a step in a calibration process in which a readout from a temperature sensor to be calibrated is compared to a known temperature to assign an actual temperature to the sensor to be calibrated, or to provide a correction to a temperature read by the temperature sensor to be calibrated.

[0044] Processor as used herein refers to an electronic processor having software and / or hardware configured to inter alia control display of a graphical user interface to display information on the graphical user interface. A processor is typically also configured to control a calibration process of a temperature sensor which preferably involves controlling an energy source to heat or cool a receptacle and to receive readouts from various sensors, such as temperature sensors used in calibration. In addition, a processor may be configured to perform arithmetic calculations used in calibration and / or used for e.g. scaling an axis in a screen of a graphical user interface.

[0045] BRIEF DESCRIPTION OF THE FIGURES

[0046] The present invention and in particular preferred embodiments will now be described in more detail with regard to the accompanying figures. The figures show ways of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

[0047] Fig.l schematically illustrates in a cross sectional view a first embodiment of a system for calibrating a temperature sensor.85705PC01

[0048] 6

[0049] Fig.2 schematically illustrates in a 3-dimensional exploded view a second embodiment of a system for calibrating a temperature sensor.

[0050] Fig.3 schematically illustrates in a cross-sectional view along A-A in Fig. 2 a second embodiment of a system for calibrating a temperature sensor

[0051] Fig. 4 is a flow chart schematically illustrating display of two screens along with a calibration process of a temperature sensor.

[0052] Fig. 5A is a schematic illustration of a start-up screen SO, Fig. 5B is a schematic illustration of a first screen SI and Fig. 5C is a schematic illustration of a second screen S2.

[0053] Fig. 6 is a schematic illustration of a third screen S3.

[0054] Fig. 7 is a schematic illustration of a fourth screen S4. Fig. 7A is an illustration of a fourth screen S4 when a temperature distribution indication value lies within a threshold, while Fig. 7B is an illustration of a fourth screen when a temperature distribution indication value is outside a threshold.

[0055] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0056] With reference to the figures, different embodiments of the invention will now be disclosed in greater details. In general, the invention relates to a calibration system 1 for calibrating a temperature sensor 2. The temperature sensor 2 is typically of a type which is to be used in a production facility or other facility where the temperature of medium, which may be solid, liquid or gaseous, is to be monitored. The temperature sensor 2 does therefore not as such form an integral part of the calibration system as the temperature sensor 2 may be arranged in the system for calibration and after calibration be placed in the facility where the temperature is to be monitored. Thus, in use, the system has received the temperature sensor 2.

[0057] In the embodiment of Fig. 1, the temperature sensor 2 has an elongate element 3 having at an end thereof an electrical sensing element 5. The temperature sensor85705PC01

[0058] 7

[0059] 2 may instead of having an electrical sensing element 5 be a mechanical temperature sensor. The electrical sensing element 5 of Fig. 1 provides a read-out representing the temperature as sensed by the temperature sensor 2 (not illustrated).

[0060] The calibration system also comprises a reference temperature sensor 19. This reference temperature sensor 19 is the element assigned to provide reference temperature measurements, that is the calibration of the temperature sensor 2 is made up against the measurements provided by the reference temperature sensor 19.

[0061] In some embodiments, a secondary or alternative reference temperature measurement may be carried out at a reference temperature sensor void (not illustrated in Fig. 1) at another position different from reference temperature sensor 19. The reference temperature sensor void is preferably arranged in the receptacle 6 close to the energy sources 10.

[0062] A processor 17 is provided and the processor is configured to control the amount of heat added to or removed from the cavity 9 by controlling the energy source 10, obtain measurements from the reference temperature sensor 19 and temperature sensor 2 and, preferably, provide a calibration for the temperature sensor 2 on the basis of said measurements.

[0063] Reference is made in particular to Fig. 1 illustrating a first embodiment of the invention. In Fig. 1 white headed arrows are used to indicate fluid motion whereas black headed arrows are used to indicate heat conduction. The indicated fluid motions in Fig. 1 are moving around and inside the fluid directing element to provide a torus-like shaped flow or a circular-like flow, such as a donut shaped flow, preferably using the inner flow passage 14 and the outer flow passage 16 connected by the flow passage above the upper end 12a of a fluid directing element 12, and the flow passage provided below the lower end 12b of the fluid directing element. Preferably, the flow has some degrees of rotational symmetry around a longitudinal axis of the elongate fluid directing element 12 preferably with a tangential circulating flow. In preferred embodiments, the fluid will circulate around in the receptacle 6, and be guided by the fluid directing element.85705PC01

[0064] 8

[0065] As illustrated, heat may be applied, which will drive or at least assist the fluid flow motions; in embodiments including a stirrer 20 this stirrer will also assist in driving the flow. In other words, fluid in the receptacle 6 will flow from outside the fluid directing element into or within the fluid directing element and vice versa. The flow shown in Fig. 1 with the upwards moving fluid closest to the tubular wall 7 and downwards moving in the space where the temperature sensors 2, 19 are arranged may be reversed.

[0066] The calibration system 1 according to the first embodiment comprising a receptacle 6 which inter alia receives the elongate element 3 of the temperature sensor 2. The receptacle 6 has a tubular wall 7, such as a cylindrical wall, closed at a lower end by a bottom 8 thereby defining an open-ended cavity 9. This cavity 9 is configured to hold a liquid by being impermeable to the fluid to be added to the receptacle 6 in the calibration process. It is also configured to receive at least a part of said elongate element 3 at least to an extent so that the end thereof with the electrical sensing element 5 is contained within cavity 9. Thereby, when a fluid is provided in the receptacle 6, the end comprising the electrical sensing element 5 is submerged in the fluid.

[0067] In the first embodiment, during the calibration process, the temperature of the fluid contained in the receptacle 6 is to be controlled, e.g. heated or cooled to one or more temperatures. To accomplish this, a controllable energy source 10 is applied and the energy source 10 is configured to add to or remove heat from the cavity 9. A predefined temperature is often used during calibration, and firstly the fluid contained in the receptacle 6 is heated or cooled by the controllable energy source 10 to the predefined temperature. When the reference temperature sensor 19 provides a stable temperature, being a temperature within a predefined range, then secondly the temperature sensor 2 measures and provides a temperature. This calibration process is preferably carried out multiple times, using different predefined temperatures, in order to calibrate the temperature sensor 2. Based on the calibration process, the provided temperatures by the temperature sensor 2 and the predefined temperatures, it is possible to derive the actual value of the temperature of the fluid in the receptacle 6 within the calibration range using interpolation. In the illustrated embodiments, the energy source 10 is arranged on an outer surface of the receptacle 6. However, the energy source 10 may be85705PC01

[0068] 9

[0069] arranged differently, such as embedded in the receptacle 6, on the inner surface of the tubular wall 7, arranged in the cavity 9 so as to be in direct contact with the fluid or even combinations thereof.

[0070] In preferred embodiments, the controllable energy source 10 is an electrical thermal element, such as a resistance heating element or a Peltier element, arranged to provide or remove thermal energy to / from the receptacle 6 when the controllable energy source 10 is provided with power from an electrical energy source (not illustrated). The amount of heating / cooling provided by the controllable energy source 10 is thus controllable by changing the voltage and / or the current provided by the electrical energy source

[0071] In the first embodiment, the receptacle 6 has a longitudinal extension in vertical direction which may give rise to a vertical and / or horizontal temperature gradient in the fluid contained in the receptacle 6. The temperature gradient may also be provided by a socket 21 of the sensor assembly having a relatively high mass which may not have the same temperature as the fluid whereby a conduction of heat may be provided between the elongate element 3 and the upper end of the temperature sensor 2.

[0072] In the first embodiment of the invention, it is suggested to solve or mitigate issues with temperature gradients inter alia by controlling the motion of the fluid within the receptacle 6. To accomplish this, the calibration system 1 has an elongate fluid directing element 12 typically configured to assist in creating a circulating motion of the fluid. The elongate fluid directing element 12 has an upper end 12a and a lower end 12b and is arranged within the cavity 9 and is dimensioned to provide an outer flow passage 14 between an outer surface of the fluid directing element 12 and an inner surface of the tubular wall 7, and an inner flow passage 16 inside an inner side the elongate fluid directing element 12 i.e. an inner flow passage 16 at an inner side of the elongate fluid directing element 12. The outer flow passage 14 and the inner flow passage 16 are in fluid communication above the upper end 12a and below the lower end 12b of the fluid directing element. As will become apparent in the following, the fluid directing element 12 may in preferred embodiments be a tubular or cylindrical element85705PC01

[0073] 10

[0074] comprised by a solid wall, including in some embodiments through going openings.

[0075] In the first embodiment, the motion of fluid in the receptacle can be buoyancy driven by heating and cooling by use of the energy source 10, such a buoyancy driven flow may be too weak or slow to provide a calibration within a reasonable time period. To avoid this, or even to provide the circulation of fluid if not occurring, the system may comprise a stirrer 20 to promote a flow of fluid going upward in the outer flow passage 14 and downward in the inner flow passage 16 or vice versa. In the embodiment shown in fig. 1, the stirrer 20 is a magnetic stirrer but other types of stirrers such as a stirrer arranged on a shaft rotated by an electrical motor may be used.

[0076] The elongate fluid directing element 12 is in the first embodiment shown as a cylindrical element, but it may be a tubular element having outer diameter or equivalent diameter (for a tubular element) being less than an inner diameter or equivalent inner diameter of the tubular wall 7. The elongate fluid directing element 12 is typically a straight element and the elongate fluid directing element 12 is typically defined by a tubular wall having thickness.

[0077] With reference to Fig. 1, the fluid directing element 12 is a cylindrical element with no through going openings provided in the wall. The fluid directing element 12 has a shorter longitudinal extension than the depth of the receptacle 6 and is arranged within the receptacle 6 in a position providing an overflow passage at the upper end 12a and an underflow passage at the lower end 12b. The fluid directing element 12 is typically suspended in position by not illustrated suspension element, such as spacers or fixation elements.

[0078] As the temperature sensor 2 in many applications is to be mounted in a facility, the temperature sensor 2 may have at a position distal to an end of the elongate element 3 a socket 21, sometimes also referred to as a "process connector", from which the elongate element 3 extends. Such a socket 21 may come in a variety of shapes, but for the purpose of disclosing the present invention, the socket 21 is in some embodiments defined to have a thickness and a diameter or equivalent diameter. The diameter or equivalent diameter of the socket 21 may be larger85705PC01

[0079] 11

[0080] than a diameter or equivalent diameter of the elongate element 3, and the thickness of the socket 21 may be smaller, equal to or larger than diameter or equivalent diameter of the elongate element 3. The thickness is typically measured transversely to the diameter, and with reference to Fig. 1 the thickness is measured in vertical direction whereas diameter is measured in horizontal direction.

[0081] Similarly, the temperature sensor 2 assembly in the first embodiment shown in Fig. 1 is typically suspended in the shown position by suspension elements not illustrated.

[0082] Reference is made to Figs. 2 and 3 illustrating a second embodiment of the invention. In the second embodiment, the calibration system 1 comprises a receptacle 6 arranged to receive an insert element 27 configured to contain a temperature sensor 2 to be calibrated. The inside of the receptacle 6 has a tubular wall 7, such as a cylindrical wall, open at an upper end and closed at a lower end by a bottom 8. Outward facing surfaces of the receptacle 6 are at least partly, such as fully, covered by a thermal insulating element 11 to thermally insulate the outward facing surfaces of the receptacle 6 from an outside environment.

[0083] In the second embodiment, the insert element 27 comprises a tubular outer wall which has an outer diameter which is substantially the same as the inner diameter of the tubular wall 7 of the receptacle 6, such that the outer wall of the insert element 27 when received in the receptacle 6 is in contact with the tubular wall 7 of the receptacle 6.

[0084] Further, the insert element 27 comprises a main sensor cavity 15 for receiving an elongate element 3a comprising a temperature sensor 2 to be calibrated. The main sensor cavity 15 comprises an opening arranged in an upper end of and substantially centred around the longitudinal axis of the insert element 27 and longitudinally extending towards the lower end of the insert element 27 (cf. Fig.

[0085] 3).

[0086] Additionally, the insert element 27 may comprise at least one reference cavity 18 arranged radially outwards from the main sensor cavity 15 when viewed along the85705PC01

[0087] 12

[0088] longitudinal direction of the insert element 27. The at least one reference cavity 18 is arranged to receive an elongate element 3 comprising at least one reference temperature sensor 19. The at least one reference cavity 18 comprises an opening arranged in the upper end of the insert element 27 longitudinally extending towards the lower end of the insert element 27 (cf. Fig. 3).

[0089] During a calibration process in the second embodiment, the temperatures of the receptacle 6 and insert element 27 are to be controlled, e.g. heated or cooled to one or more temperatures. To accomplish this, at least one controllable energy source 10 is applied and the at least one energy source 10 is configured to add to or remove heat from the receptacle 6 in order to heat the insert element 27. A predefined temperature is often used during calibration, and firstly the receptacle 6 is heated or cooled by the at least one controllable energy source 10 to the predefined temperature. In the illustrated embodiment in Fig. 3, the at least one energy source 10 is arranged in contact with outer surfaces of the receptacle 6, and at least partly integrated in the thermal insulating elements 11. However, the energy source 10 may be arranged differently, such as embedded in the tubular wall 7, on the inner surface of the tubular wall 7, arranged in the insert element 27 or even combinations thereof.

[0090] As illustrated, the receptacle 6 has a longitudinal extension in vertical direction which may give rise to a vertical and / or horizontal temperature gradient. To mitigate this, the two or more controllable energy sources 10 may be arranged at different positions around and / or along the longitudinal axis of the receptacle 6 to more evenly heat the receptacle 6, such as in at least two different positions along the longitudinal direction of the receptacle 6, as illustrated in Fig. 3. In some embodiments, the controllable energy sources 10 may have a semi-annular or annular shape, such that each controllable energy source at least partially surrounds the outer side wall of the receptacle 6.

[0091] In some embodiments, the receptacle 6 and / or the insert element 27 may be made of a high thermal conductivity material such as a metal with high conductivity in order to achieve an even temperature distribution of the receptacle and / or the insert element 27.85705PC01

[0092] 13

[0093] To increase the efficiency of the at least one controllable energy source 10, a heat sink element 31 is arranged in contact with the outward facing surfaces of the at least one controllable energy source. The heat sink element 31 may be in the form of a hollow cylinder, arranged around the outer side walls of the thermal insulating element 11 to act as a common heat sink for each of the at least one controllable energy source 10, as illustrated in figs. 2 and 3.

[0094] In other embodiments not illustrated, each of the at least one controllable energy source 10 comprises a separate heat sink element 31 covering partly, such as fully, an outward surface of each of the at least one controllable energy source 10.

[0095] The calibration system according to the second embodiment also comprises at least one reference temperature sensor 19. This at least one reference temperature sensor 19 is the element assigned to provide reference temperature measurements, that is the calibration of the temperature sensor 2 is made up against the measurements provided by the at least one reference temperature sensor 19. The reference temperature sensor 19 is preferably arranged in one of the at least one reference cavity 18 in the insert element 27.

[0096] In some embodiments, a secondary or alternative reference temperature measurement may be carried out by a reference temperature sensor 37 at another position different from the reference temperature sensor 19, outside the insert element 27. The reference temperature sensor 37 is preferably arranged in the receptacle 6 close to the energy sources 10, such as in a longitudinal cavity 38 in a wall of the receptacle 6.

[0097] In some embodiments, the insert element 27 comprises a plurality of reference cavities 18 each arranged to receive one of a plurality of elongate elements 3b comprising a reference temperature sensor 19. Each of the elongate elements 3b may have substantially the same length to provide reference temperature readings from reference temperature sensors 19 arranged at substantially the same depth within the insert element 27. In such embodiments, the reference temperature readings may be used to provide a horizontal temperature distribution of the insert element 27.85705PC01

[0098] 14

[0099] In other embodiments, the elongate elements 3b of the reference temperature sensors 19 to be arranged in each of the plurality of reference cavities 18 may have different lengths to provide reference temperature readings from reference temperature sensors 19 arranged at different depths within the insert element 27. In such embodiments, the reference temperature readings may be used to provide a vertical temperature distribution of the insert element 27.

[0100] In other embodiments, an elongate element 3b to be received in a reference cavity 18 may comprise a plurality of reference temperature sensors 19 spaced along a longitudinal axis of the elongate element to provide reference temperature readings at different depths within the insert element 27. In such embodiments, the reference temperature readings may be used to provide a vertical temperature distribution of the insert element 27.

[0101] A processor 17 is provided and the processor is configured to control the amount of heat added to or removed from the receptacle 6 by controlling the at least one energy source 10, obtain measurements from the at least one reference temperature sensor 19 and temperature sensor 2 and, preferably, provide a calibration for the temperature sensor 2 on the basis of said measurements.

[0102] Preferred embodiments of a system for calibrating a temperature sensor 2, such as a system disclosed in Figs. 1-3 has a graphical user interface 40 by which a user interacts with the system. In preferred embodiments, the system has a temperature-controlled receptacle 6 configured for receiving the temperature sensor 2 and to control the temperature of the receptacle at least up to a set temperature Ts. The set temperature is preferably a temperature at which the calibration is to be carried out.

[0103] Control the temperature of the receptacle 6 refers to that the temperature of at least the fluid or insert element 27 contained in the receptacle 6 and surrounding at least a section of the temperature sensor 2 is controlled.

[0104] The system also has at least one reference temperature sensor 19 arranged to measure a temperature inside the fluid or insert element 27. The at least one reference temperature sensor 19 may be arranged at a different point within the85705PC01

[0105] 15

[0106] receptacle 6 or within a reference cavity 18 in the insert element 27. The reference temperature sensor 19 may be arranged close to the sensing element 5 as illustrated in Fig. 1. Alternatively, or in combination therewith, a reference sensor 37 may be arranged e.g. in a longitudinal cavity 38 of the receptacle (see Fig. 3).

[0107] In some embodiments, a plurality of reference temperature sensors 19 are arranged at different depths within the reference cavities 18 of the insert element 27 or the fluid within the cavity 9 of the receptacle 6 to determine a vertical temperature distribution. In such embodiments, the processor 17 is configured to control the at least one energy source 10 based on the determined vertical temperature distribution in the insert element 27 or the cavity 9, wherein the processor controls the at least one energy source 10 to achieve a desired vertical temperature distribution within the insert element 27 or the fluid within the cavity 9.

[0108] A calibration system for calibrating a temperature sensor 2 according to the invention preferably has an encapsulation (not illustrated) and a graphical user interface 40, GUI, is provided, typically in the encapsulation. The GUI is provided so as to be visible to allow an interaction with a user. In some embodiments, the GUI is a touch-sensitive display for display of information and to receive input by a user by the user touching the display. In other embodiments, the GUI is a display and user input is provided via one or more buttons not arranged in the GUI. Such button(s) may also be provided in embodiments having a touch sensitive display.

[0109] The GUI may be arranged in or on e.g. an encapsulation. Alternatively, or in combination therewith, the GUI may be a web-based GUI, such as an application running of mobile device. The web-based GUI is configured to receive sensor data through a web-server, functionally linked to the processor 17, and display the sensor data to a user. Further, the web-based GUI is configured to receive user input data, such as inputs from a keyboard and / or a touch screen of the mobile device, and transmit the user input data to the processor 17 via the web-server.85705PC01

[0110] 16

[0111] The processor 17 controlling the calibration process as disclosed, or a separate processor, is functionally linked to the temperature sensors 2, 19, 37 to receive sensor readouts representing actual measured temperatures by the temperature sensors 2, 19, 37, and to control display information on the GUI.

[0112] The processor 17 is also configured to automatically toggle from a first screen SI to a second screen S2 in the GUI. Embodiments of such a first and second screen SI, S2 are illustrated in Fig. 5B and Fig. 5C. Automatically refers to that the processor 17 does not necessarily await an input from a user, and toggle when a predefined event has occurred in the temperature courses. Occurrence of the event is determined by the processor 17, and an event may be a fulfilment of a criterion as disclosed below.

[0113] As illustrated in Fig. 5B, the first screen SI includes absolute temperature courses Tac measured by each of the temperature sensors 2, 19, 37. Temperature course refers to a timewise progression. In the embodiment of Fig. 5B and Fig. 5C, the GUI displays result from a single temperature sensor 2 to be calibrated and the temperature measurements are labelled "CHI" based on that the temperature sensor 2 is connected to a channel 1 of the processor 17. The measurements provided by the reference temperature sensor 19, 37 are also displayed, and as the reference sensor 19, 37 is considered to be a true measurement (a measurement with an insignificant deviation from the actual temperature), the measurement by reference sensor 19, 37 are labelled "TRUE". It is noted that the invention is not limited to such labels as labels may be omitted and / or worded differently.

[0114] In the embodiments of Figs. 5B and 5C, the temperature courses are displayed. By this, the progress of the calibration process can be investigated by the user. Figs. 5B and 5C are snapshots at a given time. During a calibration process, display of Tac's is updated regularly, e.g. with frequency of 5 seconds, whereby the display at a given time will display not only the values of the given time but also the history, that is previous Tac's. As seen in Fig. 5B the Tac's approaches Ts and processor subsequently toggles to the second screen S2. An example of a second screen S2 is illustrated in Fig. 5C where the second screen S2 includes relative temperature courses Trc's. Each relative temperature course is in the85705PC01

[0115] 17

[0116] illustrated embodiment a difference between absolute temperatures measured by each of the sensors 2, 19, 37 and an average temperature Ta for each of the sensors 2, 19, 37 where the average may be determined over a time window of e.g. 60 seconds. The same labelling as disclosed in connection with Fig. 5B is used in second screen S2 with the same meaning. As for the first screen SI, such labelling may be omitted and / or wording differently.

[0117] In some embodiments, the temperature sensor to be calibrated 2 may comprise an integrated display for displaying a readout of the temperature sensor to be calibrated 2. In such embodiments, the processor 17 may only receive readouts from the reference temperature sensor 19, 37. In such embodiments, the second screen S2 may be configured to display a relative temperature course Trc representing the temperature measured by the reference temperature sensor 19, 37, labelled "TRUE", such that the temperature "TRUE" may be manually compared to the displayed readout of the temperature sensor to be calibrated 2. Alternatively, readouts from the temperature sensor to be calibrated 2 can be manually input to the processor 17, preferably by a user inputting the readout on the GUI, for automatic comparison with the "TRUE" temperature.

[0118] In order to initiate a calibration process, the processor 17 awaits an input from a user. In this regard, the processor 5 is configured to display a start-up screen SO requiring a user to provide to the processor 17 an input 41 to initiate the calibration process of the temperature sensor. Such a start-up screen SO is displayed before the first screen SI. By requiring an input from a user to initiate the calibration process, the user can control when the calibration is to be carried out and the user can, for example, perform a quality check of the system prior to initiating the calibration process. Such a quality check may include checking whether the temperature sensor 2 is correctly mounted in the system or checking other features of the system prior to initiating the calibration process. Hence, awaiting an input may limit the risk of performing a calibration with unintended effects, such as malplacements of temperature sensor 2 and / or wrong set temperature.

[0119] In preferred embodiments, once the user has provided the input, the processor 17 initiates the calibration process of temperature sensor 2. The calibration process is85705PC01

[0120] 18

[0121] typically carried out automatically based on a set of instructions stored in the processor which set of instructions changes the temperature inside the receptacle 6 in a preselected manner, such as increasing the temperature by preselected rate of change.

[0122] In preferred embodiments, the set of instructions comprises a calibration criterion, such that calibration is performed only after the calibration criterion is determined by the processor 17 to have been reached at a specified set temperature Ts. Once the processor 17 determines that the calibration criterion has been reached, temperature readings from the temperature sensor 2 and the at least one reference temperature sensor 19, 37 are compared, and the calibration is performed at that specific set temperature Ts. If the processor 17 has received instructions to perform automatic calibration of the temperature sensor 2, the processor controls the at least one controllable energy source 10 to achieve a second set temperature, and calibration is performed at said second set temperature only once the calibration criterion is determined by the processor 17 to have been reached at said second set temperature.

[0123] In preferred embodiments, the calibration criterion comprises a preselected temperature threshold. The preselected temperature threshold defines an upper and a lower deviation limit around the set temperature Ts. Alternatively, the preselected temperature threshold may be an upper and lower deviation limit determined from readings from each of the sensors, such as a deviation limit using the average temperature Ta for each of the sensors 2, 19. Readings from the at least one reference temperature sensor 19, 37 are compared to the preselected temperature threshold and, when the processor 17 determines that readings from the at least one reference temperature sensor 19, 37 falls within the upper and lower limits defined by the preselected temperature threshold, calibration of the temperature sensor 2 is performed. The preselected temperature threshold may be set by a user prior to the calibration process, or it may be calculated by the processor 17 based on historical temperature data.

[0124] In preferred embodiments, the calibration criterion further comprises a preselected stability threshold being a preselected time interval. In such embodiments, the processor 17 is configured to hold off calibrating the85705PC01

[0125] 19

[0126] temperature sensor 2 until the readings from the at least one reference temperature sensor 19, 37 has fallen within the preselected temperature threshold for a period of time that exceeds the preselected time interval. The preselected time interval may be set by a user prior to the calibration process, or it may be calculated by the processor 17 based on historical temperature data.

[0127] In embodiments where the calibration criterion comprises a preselected stability threshold being a preselected time interval, the preselected temperature threshold may alternatively be a temperature range limit. The temperature range limit may be a limit of a difference between a minimum and maximum temperature measured by each of the temperature sensors 2, 19, 37 within the preselected time interval. In such embodiments, the processor 17 is configured to hold off calibrating the temperature sensor 2 if the difference between the minimum and maximum temperature measured by each of the temperature sensors 2, 19, 37 within the preselected time interval is larger than the temperature range limit.

[0128] In embodiments comprising a plurality of reference temperature sensors 19, the calibration criterion may also comprise a temperature distribution criterion. In such embodiments, the processor 17 is configured to hold off calibrating the temperature sensor 2 until a desired temperature distribution has been achieved. The desired temperature distribution may be set by a user prior to the calibration process, or it may be calculated by the processor 17 based on historical temperature distribution data.

[0129] Alternatively, the calibration may be carried out manually, where once the temperature in the receptacle 6 has reached the set temperature Ts, the processor 17 maintains the receptacle 6 at the set temperature Ts until the processor 17 receives a user input through the GUI 40. The user input may be one or more of a request for calibration at the set temperature Ts, a request for a new set temperature Ts, or a request for automatic calibration at a new set temperature Ts or set of set temperatures.

[0130] Fig. 4 schematically illustrates in a flow chart a method carried out by the processor in a preferred embodiment. As illustrated, the processor 17 displays the start-up screen SO and awaits input to begin a calibration process. Once the input85705PC01

[0131] 20

[0132] to begin the calibration process has been provided by the user, the processor carries out the calibration process. In parallel, the processor displays the first screen SI and evaluate a criterion to be fulfilled to toggle to the second screen S2. In the embodiment of Fig. 4, the criterion relates to stability, and this will be detailed below. However, other criteria may be used.

[0133] Functionally linked preferably refers to, inter alia, that the processor 17 is configured to receive sensor readouts from the temperature sensors 2, 19 and computationally transform the readouts into the displayable information, and display the information on the GUI.

[0134] In preferred embodiments, the input 41 is an input of a numerical value of the set temperature Ts. The processor may be configured to accept a numerical value having a certain number of decimals only, which number of decimals may correspond to the accuracy ascribed to the calibration. In some embodiments, the calibration process is initiated based on completion of inputting the set temperature.

[0135] In preferred embodiments, the input 41 is a key-pressed input by which a key is pressed by the user. Such a key-pressed input 41 may initiate an automatic calibration based on a set of instructions as disclosed above. In a touch-sensitive display, the key may be visually presented in the start-up screen SO and the keypress is made on visually presented key. Alternatively, the key is a separate key, such an electrical switch. Preferably, the start-up screen SO preferably displays information referring to initiate the calibration process by providing a key-pressed input.

[0136] In preferred embodiments, the processor 17 is adapted to toggle from the first screen SI to the second screen S2 after a difference between an absolute temperature measured by one or both of said temperature sensors 2, 19 and the selected calibration temperature Ts is / are lower than a preselected threshold Th. The preselected threshold Th may be the same as the preselected temperature threshold for the calibration criterion, or it may be a different threshold altogether. The threshold Th may either be entered by a user, e.g. during display85705PC01

[0137] 21

[0138] of the start-up screen SO in the same manner as input of the set temperature Ts, or may be predefined and stored in a memory of the processor 17.

[0139] Alternatively, the threshold Th may be defined as a threshold Th around an average temperature Ta for each of the sensors 2, 19, where the average may be determined over a time window of e.g. 60 seconds.

[0140] Typical values of the threshold Th are

[0141] [-0.150;0.150].

[0142] That is, the threshold Th has an upper and lower limit, and lower than the threshold refers to that the difference between temperatures falls within the limits of the threshold e.g. within [-0.150;0.150]. As the threshold Th in general may be considered a small number compared to differences between set calibration temperatures, temperature fluctuations may bring the absolute temperature measured by one or both of said temperature sensors 2, 19 outside the threshold Th. In particular, temperature fluctuations larger than the threshold Th may occur immediately following a temperature ramp up or ramp down. If temperature fluctuations larger than the threshold Th occur after the processor has toggled from the first screen SI to the second screen S2 on the GUI, the temperature measured by one or both of said temperature sensors 2, 19 may be a temperature outside the temperature range shown on the second screen S2. Consequently, the graphs as displayed on the second screen S2 may not contain the current temperature and / or the graph as displayed on the second screen S2 may become discontinuous.

[0143] To reduce fluctuations during display of a second screen S2 a time criterion may be defined, wherein the processor 17 is configured to hold off toggling from the first screen SI to the second screen S2 until it is determined that the absolute temperature has remained within the threshold Th for longer than a set time interval. The set time interval may be the same as the preselected time interval for the calibration criterion or it may be a different time interval altogether.

[0144] The absolute temperature courses Ta may be displayed as numerical values in the first screen SI, typically together with the time at which an actual temperature is measured. While such numerical values are of relevance to a user, it may be85705PC01

[0145] 22

[0146] difficult for a user to evaluate whether, as an example, the temperatures proceed towards the set temperature Ts. To provide such information, the absolute temperature courses Ta may be displayed as a graph, as e.g. illustrated in Fig. 5B, where a user clearly can identify that the temperatures proceed towards the set temperature, hence being an effective tool for a user to evaluate the progress of the calibration process.

[0147] The relative temperature courses Tr may also be disclosed as numerical values in the second screen S2, typically together with the time at which an actual relative temperature is measured. Considering that the relative temperatures in general are small numbers, it may be difficult for a user to evaluated, as an example, whether the temperatures measured by the sensors have reached stability, that is the measured temperatures have reached a substantial steady-state. Displaying the relative temperature courses as a graph has shown to provide an effective tool for evaluating whether stability has been reached. One such example is illustrated in Fig. 5C, based on a which it may seen that the relative temperatures proceed asymptotically toward zero.

[0148] In embodiments where the absolute temperature courses and / or the relative temperature courses are displayed as graph, such graph(s) may advantageously be accompanied by a horizontal time axis and a vertical temperature axis. The horizontal time axis of the first screen SI typically shows the time elapsed since the calibration process was initiated and the horizontal time axis of the second screen S2 typically shows the time elapsed since toggling from the first screen to the second screen.

[0149] EXAMPLES ON AXIS IN FIRST SCREEN SI

[0150] In preferred embodiments, the axis of the first screen comprises:

[0151] • Timescale being the timespan covered by the time axis: 5 minutes longer than elapsed time. Maximum timescale is 2 hours.

[0152] • Temperature scale being the temperature span of the temperature axis (span determined at initiation of a calibration process):

[0153] o Temperature scale max.: = MAX(TRUE;CH1,CH2, SET-temp) + 0.02 * ABS(MAX(TRUE;CHl,CH2,SET-temp))+ 0.02 *85705PC01

[0154] 23

[0155] ABS(MIN(TRUE;CH1,CH2, SET-temp)) + MIN(10.0;MAX(ABS(CHl- READ),ABS(CH2-READ),ABS(TRUE-READ)))

[0156] o Temperature scale min.: = MIN(TRUE;CH1,CH2, SET-temp) - 0.02 * ABS(MIN(TRUE;CH1,CH2, SET-temp)) - 0.02 * ABS(MAX(TRUE;CH1,CH2, SET-temp)) - MIN(10.0;MAX(ABS(CHl- READ);ABS(CH2-READ);ABS(TRUE-READ)))

[0157] o Start-temperature = TRUE at initiation of the calibration process

[0158] The variables are defined as:

[0159] o "TRUE" is the temperature measured by one of reference temperature sensor 19 or 37;

[0160] o "READ" is the temperature measured by the temperature sensor 37; o "CHI" is the temperature measured by the temperature sensor 2 to be calibrated;

[0161] o "CH2" is the temperature measured by a further temperature sensor to be calibrated (if used);

[0162] o "SET-temp" is the value of the set temperature Ts;

[0163] In preferred embodiments, the temperature axis may have three labels:

[0164] • start temperature

[0165] • set temperature Ts

[0166] • (set temperature - start-temperature) / 2 + start-temperature

[0167] where start temperature, is the temperature measured by the reference temperature sensor 19 or 37 at the point in time where the calibration process is initiated.

[0168] In preferred embodiments, the time axis may have three labels showing elapsed time. Preferably, up till four graphs may be displayed in the first screen SI:

[0169] • set temperature (if activated), preferably labelled "SET"

[0170] • temperature measured by reference sensor 19 or 37, preferably labelled "TRUE"

[0171] • temperature measured by sensor to be calibrated 2, preferably labelled "CHI" (if activated)85705PC01

[0172] 24

[0173] • temperature measured by a further temperature sensor to be calibrated (if used), preferably labelled "CH2" (if active)

[0174] EXAMPLES ON AXIS IN SECOND SCREEN S2

[0175] Timescale being the timespan covered by the time axis (X-axis):

[0176] • total time elapsed since toggle to second screen, preferably not less than ten minutes.

[0177] • Time axis may have three labels such as "CHI", "CH2" and "TRUE".

[0178] Temperature scale being the temperature span of the temperature axis:

[0179] • ±2.0 * Maximum stability temperature setting for selected sensors with stabilization criteria selected. Labels at ± stability temperature setting and 0. Wherein the maximum stability temperature setting is the highest one of the selected thresholds Th for CHI, CH2 and TRUE.

[0180] In preferred embodiments, up till three graphs can be displayed:

[0181] • difference between set temperature Ts and temperature measured by the reference temperature sensor 19, (TRUE)

[0182] • difference between set temperature Ts and temperature measured by temperature sensor to be calibrated 2, (CHI, preferably displayed only if active)

[0183] • difference between set temperature Ts and temperature measured by a further temperature sensor to be calibrated 2, "CH2, preferably displayed only if active).

[0184] The temperature values to be displayed as graphs are preferably calculated as the

[0185] Instant temperature measured minus

[0186] an average of temperature value for the latest 60 seconds.

[0187] In preferred embodiments, one or more, such as all of measured temperatures is measured as an average temperature within a preselected time window preferably having a length of between 30 and 60 seconds, such as between 40 and 50 seconds.85705PC01

[0188] 25

[0189] Such an average may be determined by:

[0190]

[0191] As temperature measurements typically are provided with at a sampling rate, the above integral is typically evaluated by a sum-function.

[0192] In preferred embodiments, the system is adapted to vary the temperature within the receptacle between a first set temperature Tsl and a second set temperature Ts2 and provide a calibration of a sensor to be calibrated to operate between these two temperatures. Such variations of the temperature can advantageously be used to calibrate a thermostatic device, where the thermostatic device e.g. opens for a flow of water at an opening temperature and closes for the flow of water at a closing temperature. The first set temperature Tsl and the second set temperature Ts2 are selected such that the thermostatic device opens and closes between or at the first Tsl and second Ts2 set temperature. The first set temperature Tsl is typically lower than the temperature of the second set temperature Ts2. In such embodiments, the processor 17 is configured to control the temperature of the receptable 6 between the first set temperature Tsl and the second set temperature Ts2 to calibrate the temperature sensor 2. The rate of change in temperature, AT / seconds, is predefined and in preferred embodiments, the user input the rate of change in temperature to the system and the processor 17 receives this input and controls the temperature accordingly. Tsl and Ts2 are also input to the system and used by the processor 17 to control the temperature changes in the receptacle 6.

[0193] Before the system begins to vary the temperature between Tsl and Ts2, the system is heated or cooled towards Tsl as the set temperature Ts. Once the temperature in the receptacle 6 has reached Tsl, the calibration process is carried out as above, and when the criterion to toggle to a third screen S3 is reached, the third screen S3 is activated with the display of the temperature courses Trc being one or more of temperature measured by temperature sensor to be calibrated 2 and / or temperature measured by the reference sensor 19 or 37. The criterion to toggle to the third screen S3 may be the same as the criterion to toggle to the second screen S2 as detailed above, or it may be a different criterion altogether.85705PC01

[0194] 26

[0195] In preferred embodiments, the control of the temperature is a cyclic increase and decrease of the temperature between the first set temperature Tsl and the second set temperature Ts2.

[0196] In a further embodiment, the calibration process is a calibration process of a thermostatic device. In such embodiments, the processor 17 may be configured to display a third screen S3 on the GUI. As for the first and the second screen, it has been found advantageous to display the temperature courses Tc in the third screen S3 as a graph. An example of a calibration process of a thermostatic device is illustrated in Fig. 6, which is an example of the third screen S3. The third screen S3 contains a graph of temperature as read by a reference temperature sensor 19, 37 over time during calibration between the first set temperature Tsl and the second set temperature Ts2. Markings (*) on the graph indicate the points where the thermostatic device changes from an open / closed configuration to a closed / open configuration. As such, the third screen S3 indicates, to a user, the true temperature at which a thermostatic device switches configuration.

[0197] A calibration process of a sensor or a thermostatic device between a first set temperature Tsl and a second set temperature Ts2 may in preferred embodiment display the following screens:

[0198] • Display start-up screen SO:

[0199] o Input first set temp Tsl and second set temperature Ts2;

[0200] • Calibrate for Tsl:

[0201] o display first screen SI;

[0202] • Calibrate for Ts2:

[0203] o display third screen S3;

[0204] • End of calibration process.

[0205] Wherein the steps "Calibrate for Tsl" or "Calibrate for Ts2" may comprise changing the temperature to Tsl or Ts2, respectively. Further details of the process are described above.85705PC01

[0206] 27

[0207] In case the calibration process is cyclic for instance with three cycles as disclosed in Fig. 6, the following screens is displayed in a preferred embodiment:

[0208] • Display start-up screen SO:

[0209] o Input first set temp Tsl and second set temperature Ts2;

[0210] • Calibrate for Tsl:

[0211] o display first screen SI;

[0212] • Calibrate for Ts2:

[0213] o display third screen S3;

[0214] • Calibrate for Tsl:

[0215] o display third screen S3;

[0216] • Calibrate for Ts2:

[0217] o display third screen S3;

[0218] • Calibrate for Tsl:

[0219] o display third screen S3;

[0220] • Calibrate for Ts2:

[0221] o display third screen S3;

[0222] • Calibrate for Tsl:

[0223] o Display third screen S3;

[0224] • End of calibration process.

[0225] As mentioned above the first and the second set temperatures are input to the system. In preferred embodiments, the first set temperature Tsl and / or the second set temperature Ts2 is / are the input 41 input to initiate the calibration process.

[0226] In some embodiments, the processor 17 may be configured to calculate a temperature distribution indication, TDI, -value, where the TDI-value is a difference between actual measured temperatures of at least two of the reference temperature sensors 19, 37. The processor may further be configured to display said TDI-value on a fourth screen (S4).

[0227] In preferred embodiments, the TDI-value is determined by the processor 17 according to the following calculation:85705PC01

[0228] 28

[0229] o TDI = TRUE1-TRUE2

[0230] The variables are defined as:

[0231] o "TRUE1" is the temperature measured by one of the at least two reference temperature sensors 19;

[0232] o "TRUE2" is the temperature measured by a different one of the at least two reference temperature sensors 19 or 37;

[0233] In some embodiments, as illustrated in Fig. 3, the at least two reference temperature sensors 19 are arranged at different vertical positions to provide actual measured temperatures at different vertical positions in the receptacle 6. In such embodiments, the TDI-value is indicative of a vertical temperature distribution.

[0234] In some embodiments, as illustrated in Fig. 3, the at least two reference temperature sensors 19, 37 are arranged at different horizontal positions to provide actual measured temperatures at different horizontal positions in the receptacle 6. In such embodiments, the TDI-value is indicative of a horizontal temperature distribution.

[0235] In some embodiments, the input 41 provided by a user may include a TDI-value threshold TDI-Th. The TDI-value threshold TDI-Th is preferably a maximum absolute TDI-value, such that it defines a maximum allowable difference in temperature as measured by at least two reference temperature sensors 19, 37 at different positions.

[0236] In preferred embodiments, the processor 17 is configured to control the at least one controllable energy source 10 based on the TDI-value. Preferably, the processor 17 controls the at least one controllable energy source 10 to attain a lower absolute TDI-value, such as a TDI-value of substantially zero.

[0237] In preferred embodiments, the processor 17 is configured to display an indication on the fourth screen S4, informing the user of whether the TDI-value is within the TDI-value threshold. The indication may be as illustrated in Fig. 7A and 7B. Fig.

[0238] 7A is an example of a fourth screen S4 displaying a TDI-value indicated by a85705PC01

[0239] 29

[0240] horizontal line, TDI, lying within the TDI-value threshold indicated by two dashed lines, TDI-Th, indicating that the TDI-value is within the TDI-value threshold. Fig.

[0241] 7B is an example of the fourth screen S4 displaying a TDI-value indicated by a horizontal line, TDI, lying outside the TDI-value threshold indicated by two dashed lines, TDI-Th, indicating that the TDI-value is within the TDI-value threshold.

[0242] In some embodiments, when performing an automatic calibration process, the processor 17 may be configured to perform calibration only if the TDI-value is within the TDI-value threshold.

[0243] In embodiments where the calibration process includes a TDI-value threshold TDI-Th, the first screen SI, second screen S2 and / or third screen S3 may be shown together with an indication of whether the TDI-value is within the TDI-value threshold TDI-Th. Preferably, the indication of whether the TDI-value is within the TDI-value threshold TDI-Th may be comprised on the fourth screen S4.

[0244] The screens disclosed herein provides a user the possibility to make a supervised calibration process and calibration. In some preferred embodiments, the calibration is ended by a user input an end calibration input signalling to the processor 17 to end the calibration. Hence, in such embodiments, the system for calibration a temperature sensor is configured to receive such an end calibration input from a user.

[0245] In preferred embodiments, the GUI is a touch-sensitive display and is configured to receive the end calibration input by a user touching the display in a designated area of said GUI. Such a designated area may a graphical symbol informing the user to touch this symbol to end calibration and may be implemented in one or more such as all the screens SCI, SC2, SC3, and SC4 disclosed herein. In combination therewith or as an alternative, the system may comprise one or more buttons configured for the user to input the end calibration input, typically as a key-pressed input.

[0246] As the user can supervise the calibration process, the user may also recognise that the calibration process is not occurring as it should, such as as per design, and the user might want to cancel an ongoing calibration. To this, the system may85705PC01

[0247] 30

[0248] be configured to receive a cancellation calibration input from a user during an ongoing calibration process, and if said cancellation calibration input is received, the processor 17 terminates said ongoing calibration process.

[0249] In preferred embodiments, the GUI is a touch-sensitive display and is configured to receive the cancellation calibration input by a user touching the display in a designated area of said GUI. Such a designated area may a graphical symbol informing the user to touch this symbol to cancel calibration and may be implemented in one or more such as all the screens SCI, SC2, SC3, and SC4 disclosed herein. In combination therewith or as an alternative, the system may comprise one or more buttons configured for the user to input the cancellation calibration input, typically as a key-pressed input.

[0250] The invention can be implemented by means of hardware, software, firmware or any combination of these. The invention or some of the features thereof can also be implemented as software running on one or more data processors and / or digital signal processors.

[0251] The individual elements of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way such as in a single unit, in a plurality of units or as part of separate functional units. The invention may be implemented in a single unit, or be both physically and functionally distributed between different units and processors.

[0252] Although the present invention has been described in connection with the specified embodiments, it should not be construed as being in any way limited to the presented examples. The scope of the present invention is to be interpreted in the light of the accompanying claim set. In the context of the claims, the terms "comprising" or "comprises" do not exclude other possible elements or steps. Also, the mentioning of references such as "a" or "an" etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention. Furthermore, individual features mentioned in different claims, may possibly be advantageously combined, and the mentioning of these features85705PC01

[0253] 31

[0254] in different claims does not exclude that a combination of features is not possible and advantageous.

[0255] ITEMIZED LIST OF PREFERRED EMBODIMENTS

[0256] Item 1. A system for calibrating a temperature sensor (2), comprising:

[0257] a temperature-controlled receptacle (6) configured for receiving said temperature sensor (2) and to control the temperature of said receptacle at least up to a set temperature (Ts);

[0258] at least one reference temperature sensor (19, 37) arranged to measure a temperature inside said temperature-controlled receptacle (6);

[0259] a graphical user interface (40), GUI,

[0260] a processor (17) functionally linked to

[0261] said temperature sensors (2, 19, 37) to receive sensor readouts representing actual measured temperatures by said temperature sensors (2, 19, 37), and control display information on the GUI;

[0262] and is configured to automatically toggle from a first screen (SI) to a second screen (S2) in said GUI, wherein

[0263] said first screen (SI) including absolute temperature courses (Tac) measured by each of said temperature sensors (2, 19, 37), said temperature courses are displayed together with said set temperature (Ts);

[0264] said second screen (S2) including temperature courses (Tc) measured by each of said sensors (2,19, 37) timewise after said second screen (S2) has been toggled wherein said processor (17) is configured

[0265] to display a start-up screen (SO) requiring a user to provide to said processor (17) an input (41) to initiate a calibration process of said temperature sensor, and to initiate a calibration process of said temperature sensor (2) after said input (41) has been provided by said user.

[0266] Item 2. A system according to item 1, wherein said temperature courses (Tc) are relative temperature courses (Trc), each relative temperature course is a difference between absolute temperatures measured by each of said sensors (2,19) and said set temperature (Ts).

[0267] Item 3. A system according to any one of the preceding items, wherein said input (41) is an input of a numerical value of said set temperature (Ts).85705PC01

[0268] 32

[0269] Item 4. A system according to any one of the preceding items wherein said input (41) is a key-pressed input, where said start-up screen (SO) preferably displays information referring to initiate said calibration process by providing a key-pressed input.

[0270] Item 5. A system according to any one of the preceding items, wherein said processor is adapted to toggle from said first screen (SI) to said second screen (S2) after

[0271] a difference between an absolute temperature measured by one or both of said temperature sensors (2, 19) and said selected calibration temperature (Ts) is(are) lower than a preselected threshold (Th).

[0272] Item 6. A system according to item 5, wherein said thresholds each is a limit on temperature variations over a defined time window.

[0273] Item 7. A system according to any one of the preceding items, wherein said absolute temperature courses (Ta) is displayed as a graph.

[0274] Item 8. A system according to any one of the preceding items, when dependent on item 2, wherein said relative temperature courses (Tr) is displayed as a graph.

[0275] Item 9. A system according to item 7 or 8, wherein said graph(s) comprising a horizontal time axis and a vertical temperature axis.

[0276] Item 10. A system according to any one of the preceding items, wherein one or more of said measured temperatures are determined as an average temperature within a preselected time window preferably having a length of between 30 and 60 seconds, such as between 40 and 50 seconds.

[0277] Item 11. A system according to any one of the preceding items, wherein a calibration is performed only after the processor 17 determines that a calibration criterion has been met.

[0278] Item 12. A system according to any one of the preceding items, wherein85705PC01

[0279] 33

[0280] said processor (17) is configured to control the temperature of said receptable (6) between a first set temperature (Tsl) and a second set temperature (Ts2) with a pre-defined rate of change in temperature,

[0281] said temperature courses (Tc) are one or more of

[0282] temperature measured by temperature sensor to be calibrated (2), temperature measured by the reference sensor (19).

[0283] Item 13. A system according to item 12, wherein said control of the temperature is a cyclic increase and decrease of the temperature between said first set temperature (Tsl) and said second said temperature (Ts2).

[0284] Item 14. A system according to item 12 or 13, wherein said temperature courses (Tc) is / are displayed as a graph.

[0285] Item 15. A system according to any one of items 12-14, wherein the first set temperature (Tsl) and / or said second set temperature (Ts2) is / are said input (41) to initiate calibration.

[0286] Item 16. A system for calibrating a temperature sensor (2), comprising:

[0287] at least two reference temperature sensors (19, 37) arranged to measure temperatures inside a temperature-controlled receptacle (6);

[0288] a graphical user interface (40), GUI,

[0289] a processor (17) functionally linked to

[0290] said reference temperature sensors (19, 37) to receive sensor readouts representing actual measured temperatures by said reference temperature sensors (19, 37), and

[0291] control display information on said GUI;

[0292] wherein said processor (17) is configured

[0293] to display a start-up screen (SO) requiring a user to provide to said processor (17) an input (41) to initiate a calibration process of said temperature sensor, and to initiate a calibration process of said temperature sensor (2) after said input (41) has been provided by said user, and

[0294] to determine a temperature distribution indication, TDI, -value (TDI), said TDI-value (TDI) comprising a difference between actual measured temperatures of at least two reference temperature sensors (19, 37).85705PC01

[0295] 34

[0296] Item 17. A system according to item 16, wherein said at least two reference temperature sensors (19, 37) are arranged to provide actual measured temperatures at different vertical positions inside the temperature-controlled receptacle (6).

[0297] Item 18. A system according to any one of items 16 or 17 wherein said at least two reference temperature sensors (19, 37) are arranged to provide actual measured temperatures at different horizontal positions inside the temperature-controlled receptacle (6).

[0298] Item 19. A system according to any one of items 16-18, wherein said processor is further configured to display a fourth screen (S4) on said GUI including said TDI-value (TDI).

[0299] Item 20. A system according to any one of items 16-19, wherein said input (41) is an input of a TDI-value threshold (TDI-Th).

[0300] Item 21. A system according to item 20, wherein said processor (17) is further configured to control the temperature of said receptacle (6) based on said TDI-value (TDI) and said TDI-value threshold (TDI-Th).

[0301] Item 22. A system according to item 20 or 21, wherein said processor (17) is configured to provide an indication on said fourth screen (S4) of whether said TDI-value (TDI) is within said TDI-value threshold (TDI-Th).

[0302] Item 23. A system according to any one of items 20-22, wherein said processor (17) is configured to perform calibration only if said TDI-value (TDI) is within said TDI-value threshold (TDI-Th).

[0303] Item 24. A system according to any one of items 19-23, wherein said fourth screen (S4) is displayed together with at least one of a first (SI), second (S2) and / or third (S3) screen.85705PC01

[0304] 35

[0305] LIST OF REFERENCE SYMBOLS USED

[0306] 1 System for calibrating a temperature sensor 2 Temperature sensor

[0307] 3 Elongate element

[0308] 5 Electrical sensing element

[0309] 6 Receptacle

[0310] 7 Tubular wall

[0311] 8 Bottom

[0312] 9 Cavity

[0313] 10 Energy source

[0314] 11 Thermal insulating element

[0315] 12 Fluid directing element

[0316] 12a Upper end

[0317] 12b Lower end

[0318] 14 Outer flow passage

[0319] 15 Main sensor cavity

[0320] 16 Inner flow passage

[0321] 17 Processor

[0322] 18 Reference cavity

[0323] 19 Reference temperature sensor

[0324] 20 Stirrer

[0325] 21 Socket

[0326] 23 Abutment surface

[0327] 24 Lower surface

[0328] 25 through going opening

[0329] 26 Opening

[0330] 27 Insert element

[0331] 31 Heat sink element

[0332] 37 Reference temperature sensor

[0333] 38 Longitudinal cavity

[0334] 40 Graphical User interface, GUI

[0335] 41 Input

[0336] SO Start-up screeen

[0337] SI First screen85705PC01

[0338] 36 52 Second screen

[0339] 53 Third screen

[0340] Tac Absolute temperature course Trc Relative temperature course Ta Average temperature

[0341] Ts Set temperature

[0342] Th Threshold

Claims

85705PC0137CLAIMS1. A system for calibrating a temperature sensor (2), comprising:a temperature-controlled receptacle (6) configured for receiving said temperature sensor (2) and to control the temperature of said receptacle at least up to a set temperature (Ts);at least one reference temperature sensor (19, 37) arranged to measure a temperature inside said temperature-controlled receptacle (6);a graphical user interface (40), GUI,a processor (17) functionally linked to• said temperature sensors (2, 19, 37) to receive sensor readouts representing actual measured temperatures by said temperature sensors (2, 19, 37), and• control display information on the GUI;and is configured to automatically toggle from a first screen (SI) to a second screen (S2) in said GUI, whereino said first screen (SI) including absolute temperature courses (Tac) measured by each of said temperature sensors (2, 19, 37), said temperature courses are displayed together with said set temperature (Ts);o said second screen (S2) including temperature courses (Tc) measured by each of said sensors (2,19, 37) timewise after said second screen (S2) has been toggledwherein said processor (17) is configuredto display a start-up screen (SO) requiring a user to provide to said processor (17) an input (41) to initiate a calibration process of said temperature sensor, andto initiate a calibration process of said temperature sensor (2) after said input (41) has been provided by said user.

2. A system according to claim 1, wherein said temperature courses (Tc) are relative temperature courses (Trc), each relative temperature course is a difference between absolute temperatures measured by each of said sensors (2,19) and said set temperature (Ts).85705PC01383. A system according to any one of the preceding claims, wherein said input (41) is an input of a numerical value of said set temperature (Ts).

4. A system according to any one of the preceding claims wherein said input (41) is a key-pressed input, where said start-up screen (SO) preferably displays information referring to initiate said calibration process by providing a key-pressed input.

5. A system according to any one of the preceding claims, wherein said processor is adapted to toggle from said first screen (SI) to said second screen (S2) after a difference between an absolute temperature measured by one or both of said temperature sensors (2, 19) and said selected calibration temperature (Ts) is(are) lower than a preselected threshold (Th).

6. A system according to claim 5, wherein said thresholds each is a limit on temperature variations over a defined time window.

7. A system according to any one of the preceding claims, wherein said absolute temperature courses (Ta) is displayed as a graph.

8. A system according to any one of the preceding claims, when dependent on claim 2, wherein said relative temperature courses (Tr) is displayed as a graph.

9. A system according to claim 7 or 8, wherein said graph(s) comprising a horizontal time axis and a vertical temperature axis.

10. A system according to any one of the preceding claims, wherein one or more of said measured temperatures are determined as an average temperature within a preselected time window preferably having a length of between 30 and 60 seconds, such as between 40 and 50 seconds.

11. A system according to any one of the preceding claims, wherein a calibration is performed only after the processor (17) determines that a calibration criterion has been met.85705PC013912. A system according to any one of the preceding claims, wherein• said processor (17) is configured to control the temperature of said receptable (6) between a first set temperature (Tsl) and a second set temperature (Ts2) with a pre-defined rate of change in temperature,• said temperature courses (Tc) are one or more ofo temperature measured by temperature sensor to be calibrated (2), o temperature measured by the reference sensor (19).

13. A system according to claim 12, wherein said control of the temperature is a cyclic increase and decrease of the temperature between said first set temperature (Tsl) and said second said temperature (Ts2).

14. A system according to claim 12 or 13, wherein said temperature courses (Tc) is / are displayed as a graph, preferably in a third screen (S3).

15. A system according to any one of claims 12-14, wherein the first set temperature (Tsl) and / or said second set temperature (Ts2) is / are said input (41) to initiate calibration.

16. A system for calibrating a temperature sensor (2), comprising:at least two reference temperature sensors (19, 37) arranged to measure temperatures inside a temperature-controlled receptacle (6);a graphical user interface (40), GUI,a processor (17) functionally linked to• said reference temperature sensors (19, 37) to receive sensor readouts representing actual measured temperatures by said reference temperature sensors (19, 37), and• control display information on said GUI;wherein said processor (17) is configuredto display a start-up screen (SO) requiring a user to provide to said processor (17) an input (41) to initiate a calibration process of said temperature sensor, andto initiate a calibration process of said temperature sensor (2) after said input (41) has been provided by said user, and85705PC0140to determine a temperature distribution indication, TDI-value (TDI), said TDI-value (TDI) comprising a difference between actual measured temperatures of at least two reference temperature sensors (19, 37).

17. A system according to claim 16, wherein said at least two reference temperature sensors (19, 37) are arranged to provide actual measured temperatures at different vertical positions inside the temperature-controlled receptacle (6).

18. A system according to any one of claims 16 or 17 wherein said at least two reference temperature sensors (19, 37) are arranged to provide actual measured temperatures at different horizontal positions inside the temperature-controlled receptacle (6).

19. A system according to any one of claims 16-18, wherein said processor is further configured to display a fourth screen (S4) on said GUI including said TDI-value (TDI).

20. A system according to any one of claims 16-19, wherein said input (41) is an input of a TDI-value threshold (TDI-Th).

21. A system according to claim 20, wherein said processor (17) is further configured to control the temperature of said receptacle (6) based on said TDI-value (TDI) and said TDI-value threshold (TDI-Th).

22. A system according to claim 20 or 21, wherein said processor (17) is configured to provide an indication on said fourth screen (S4) of whether said TDI-value (TDI) is within said TDI-value threshold (TDI-Th).

23. A system according to any one of claims 20-22, wherein said processor (17) is configured to perform calibration only if said TDI-value (TDI) is within said TDI-value threshold (TDI-Th).

24. A system according to any one of the preceding claims, wherein said system is configured to receive an end calibration input from a user.85705PC014125. A system according to claim 24, wherein• said GUI is a touch-sensitive display and is configured to receive said end calibration input by a user touching the display in a designated area of said GUI, and / or• said system comprises one or more buttons configured for the user to input said end calibration input.

26. A system according to any one of the preceding claims, wherein said system is configured to receive a cancellation calibration input from a user during an ongoing calibration process, and if said cancellation calibration input is received, said processor (17) terminates said ongoing calibration process.

27. A system according to claim 26, wherein• said GUI is a touch-sensitive display and is configured to receive said cancellation calibration input by a user touching the display in a designated area of said GUI, and / or• said system comprises one or more buttons configured for the user to input said cancellation calibration input.

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