TEMPERATURE CALIBRATOR WITH ADVANCED FUNCTIONALITY

Abstract

The present invention combines the functionalities of a multifunctional process calibrator with a heating and/or cooling unit (also called as a dry block). The heating and/or cooling unit and the process calibrator are integrated in a single housing forming the arrangement. The arrangement allows using several digital communication protocols i.e. fieldbus protocols. Temperature sensor simulation is possible as well. Pressure measurement and/or calibration is also enabled. The arrangement is supplied with internal rechargeable battery, which enables all other functionalities without mains power, except the use of the heating and/or cooling unit, where the mains power is required.

Claims

1. An arrangement configured to measure or calibrate at least a temperature sensor, wherein the arrangement comprises: a processor; at least one pair of connecting terminals; a heating and/or cooling unit, comprising at least one heating and/or cooling element for heating and/or cooling a desired part of the arrangement; an insert configured as a place for a temperature sensor to be calibrated, wherein the arrangement further comprises: a process calibrator capable of operations, measurements and generations concerning at least two different quantities; wherein the heating and/or cooling unit and the process calibrator are integrated in a single housing forming the arrangement.

2. The arrangement according to claim 1, wherein the at least one heating and/or cooling element is a Peltier element or a resistive heating element, depending on a desired temperature area of the arrangement.

3. The arrangement according to claim 1, wherein the arrangement comprises a user interface, comprising LED indicators, a screen, and a keyboard, where the LED indicators are configured to show warning signals to a user, and a screen is configured to show connection instructions relating to the at least one pair of connecting terminals to the user relating to a desired measurement or calibration.

4. The arrangement according to claim 1, wherein the arrangement is configured to comprise at least two different fieldbus protocol modules enabling communication in at least two different fieldbus protocols.

5. The arrangement according to claim 4, wherein the fieldbus protocols are selected among a group of HART, FOUNDATION Fieldbus and Profibus fieldbus protocols.

6. The arrangement according to claim 1, wherein the arrangement comprises: an internal, rechargeable battery, which is configured to provide power supply to at least one functionality of the arrangement except for the use of the at least one heating and/or cooling element.

7. The arrangement according to claim 1, wherein the arrangement comprises: a temperature sensor signal simulation configured to create a temperature sensor signal based on a temperature input value, and to feed the created temperature sensor signal to a desired location in a measurement circuit in the field.

8. The arrangement according to claim 1, wherein the arrangement comprises a pressure measurement module configured to measure or calibrate pressure of a pressure sensor.

9. The arrangement according to claim 1 erg, wherein the arrangement further comprises: a plurality of resistance (R) or resistance temperature detector (RTD) measurement channels, and a plurality of thermocouple measurement channels.

10. The arrangement according to claim 1, wherein the arrangement is configured to execute performed settings, method steps, measurements, calibrations, and data transmission/receptions by applying a calibration software, which is common in the process calibrator and in an external computer used in a control room, allowing data flow between the arrangement and the external computer, and measurement/calibration data storage to a desired location.

11. The arrangement according to claim 3, wherein the arrangement is configured to inform excessive heat within the arrangement with a warning indicator via the LED or via the screen.

12. The arrangement according to claim 11, wherein the arrangement further comprises: an accelerometer, which is configured to sense, whether an inclination angle of the arrangement exceeds a threshold angle or whether the arrangement has tipped over to its side, and a fan, wherein the arrangement is configured to switch off the heating and/or cooling elements and to turn on the fan.

13. The arrangement according to claim 1, wherein the arrangement comprises a connection to an external temperature controller or to an external pressure controller.

14. The arrangement according to claim 1, wherein the arrangement comprises reference sensors, which comprise a memory chip configured to store sensor coefficients, and wherein the arrangement is configured to automatically read and use the sensor coefficients after the insertion of the reference sensors into the arrangement.

15. A method for measuring or calibrating at least a temperature sensor, wherein the method comprises the steps of: controlling an arrangement by a processor; allowing connections to instruments or sensors to be measured by at least one pair of connecting terminals; performing heating and/or cooling of a desired part of the arrangement by a heating and/or cooling unit comprising at least one heating and/or cooling element, when desired; placing a temperature sensor in an insert for calibration, wherein the method further comprises the steps of: performing at least one operation and/or measurement and/or generation by a process calibrator, where the process calibrator is capable of operations, measurements and generations concerning at least two different quantities; wherein integrating the heating and/or cooling unit and the process calibrator in a single housing forming the arrangement.

16. A computer program for measuring or calibrating at least a temperature sensor, the computer program comprising program code which is executable in a processor, wherein the computer program is configured to execute the steps of: controlling an arrangement by the processor; where the arrangement comprises at least one pair of connecting terminals for connections to instruments or sensors to be measured, and the arrangement allows a temperature sensor to be placed in an insert for calibration; performing heating and/or cooling of a desired part of the arrangement by a heating and/or cooling unit comprising at least one heating and/or cooling element, when desired; wherein the computer program is further configured to execute the step of: performing at least one operation and/or measurement and/or generation by a process calibrator, where the process calibrator is capable of operations, measurements and generations concerning at least two different quantities; wherein the heating and/or cooling unit and the process calibrator are integrated in a single housing forming the arrangement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 illustrates an embodiment according to the present invention, showing an arrangement comprising a dry block and a multifunctional process calibrator.

DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention addresses the drawbacks mentioned in the background, and presents an arrangement which reduces the number of required devices, and makes the calibration process much more convenient for the user.

[0031] The present invention introduces an arrangement for a versatile temperature calibration with advanced functionalities. Such an arrangement is achieved with embodiments which comprise a multifunctional process calibrator, and a dry block i.e. a temperature heat source, and certain additional features not common in the market currently.

[0032] In other words, the present invention in its many embodiments comprise a single integrated calibration device, which comprises the functionalities of a multifunctional process calibrator, and the heating and cooling operability achieved by heating and/or cooling elements of a dry block. In other words, it can be said that the present invention is an advanced temperature dry block integrated with characteristics of a multifunctional process calibrator. The dry block gives a user a possibility to heat and cool the calibrated sensor(s) to a desired stable temperature, usually via a metal block integrated in the device.

[0033] In an embodiment of the present invention, a versatile and portable automated temperature calibration arrangement is achieved by combining a multifunctional process calibrator and a dry block. A dry block is a temperature calibrator that applies heating and/or cooling to the metal block so that the metal block will reach a specific temperature and maintain that temperature. Usually the dry block may have at least one interchangeable insert, where holes are drilled. These holes can be accommodated by temperature sensors, which are to be calibrated. An important thing is that the temperature sensor close fits into the hole physically so that there is a good heat transfer between the sensor and the insert.

[0034] This arrangement is able to generate a desired temperature in a wide range by heating and/or cooling elements which can be e.g. Peltier elements or resistive heaters based on the desired temperature range. In addition to that, the arrangement is able to measure and simulate temperature, and also to measure and simulate a wide range of electrical signals provided by the multifunctional process calibrator. Also pressure measurement and calibration is possible in an embodiment of the present invention.

[0035] The arrangement is designed to be used in wide range of industrial environments, and also it is able to minimize the impact of varying environmental conditions (such as temperature or moisture levels, for instance), and variations in incoming AC power for the arrangement.

[0036] FIG. 1 illustrates a general embodiment of the arrangement 11 according to the present invention, where a multifunctional process calibrator 12 and a heating/cooling functionality of a dry block 22 are integrated together. It is notable that not all possible functional entities are shown there; only some of the common parts are shown for illustrative purposes.

[0037] The arrangement 11 comprises a multifunctional process calibrator 12, which in turn comprises a processor 15, a memory 16, a User Interface (“UI”) 13 comprising a screen, LED indicators, and possibly a keyboard (or alternatively a touch screen and LED indicators), and connecting terminals for the sensor 21 to be measured or calibrated. The arrangement 11 comprises an insert 20 where the temperature sensor 21 to be calibrated can be placed. The heating and/or cooling unit 22 comprising heating and/or cooling element(s) is a relevant part of the arrangement 11. Furthermore, there can be an accelerometer 23 for measuring an inclination angle of the device (i.e. the arrangement housing). Such sensing means 23 is also capable to detect a full tipping of the device over its side. There is an internal, rechargeable battery 17, a fan 18 and a plurality of fieldbus protocol modules 19 (at least two of them). In an embodiment, there are three different fieldbus protocol modules. The arrangement 11 can be used in the field by the user 24. There can also be an external computer in a control room (not shown), where measurement/calibration data can also be shown, analyzed and stored.

[0038] Many alternative and additional functional modules are possible, and they are disclosed elsewhere in this description.

[0039] The arrangement is provided with a modern user interface, which in an embodiment is a touch screen providing multi-color information, multilingual instructions possibilities, and graphical and numerical viewing possibilities. This results in an easy and enjoyable user experience. The touch screen is built so that it is able to receive accurate input data, no matter whether the user is using bare fingers, hands with gloves or some form of a stylus.

[0040] In an embodiment, the arrangement is configured to provide support for a plurality of digital fieldbus protocols and corresponding communication principles. These functionalities can be integrated in the manufactured arrangement e.g. in a form of parallel modules, each applying a dedicated fieldbus protocol. In an embodiment, the supported fieldbus protocols are at least two from the group of HART, FOUNDATION Fieldbus and Profibus fieldbus protocols. An imminent advantage of using a plurality of supported fieldbus protocols is that a single arrangement allows calibrating a group of instruments which communicate under more than one fieldbus protocol, without a need to use two or more separate calibrator devices for all the calibrations.

[0041] The arrangement according to the invention can be considered as “a mobile calibration laboratory”, which replaces a large number of conventional, separate single-function calibration devices. Thus, the arrangement is a compact solution, allowing the user to carry it easily with him/her in the field environment (such as a plant, factory or automation line). This is a great advantage of the presented arrangement.

[0042] In an embodiment, the heating and cooling processes by the dry block are designed so that there are no overshoots even in the case where the heating and cooling speed is relatively large. This improves efficiency and shortens the measurement and calibration times. The maximum velocity for the rate of change of the temperature can be set by the user.

[0043] In an embodiment, the process calibrator according to the arrangement comprises a plurality of resistance (R) or RTD measurement channels, and a plurality of thermocouple measurement channels. In a more detailed embodiment, the number of the resistance/RTD measurement channels can be three, and the number of thermocouple measurement channels can be two. There can also be connection(s) for measuring and/or generating various DC electrical signals.

[0044] In an embodiment, the arrangement comprises an ability to create a simulated temperature sensor signal. Such a need often arises when a temperature sensor is calibrated in the dry block of the arrangement, in connection of calibrating temperature measurement loops and/or instruments. In this situation, it is common that a signal created by a temperature sensor needs to be fed into a measurement circuit. This embodiment creates a simulated temperature sensor signal, which can be fed to an appropriate location in one or more measurement circuits. In an embodiment, the presented arrangement simulates signals based on an RTD (i.e. resistance temperature detector) or from a thermocouple measurement, and the arrangement can forward it to a desired place in a measurement circuit (or simulate several signals and feed them to a plurality of desired locations). In other words, the temperature sensor signal simulation means that a sensor is “mimicked” and the simulation means generates an appropriate resistance value (concerning a RTD sensor) or voltage value (concerning a thermocouple) so that it corresponds to the sensor's “output” when the sensor is placed in that particular temperature. In practice, the simulation means works so that the user may input a temperature value (i.e. a temperature input value) to a simulating device, e.g. 100° C., and the simulating device will simulate a correct resistance or voltage, which the sensor would output, if it located in that particular inputted temperature (i.e. in the temperature input value). An advantage of this embodiment is that the dry blocks according to the prior art have not been capable of doing this. A further advantage is that the user does not have to carry a separate device for the sensor simulation.

[0045] In an embodiment, the arrangement can be connected to an external pressure module which can be used for various pressure measurements and calibrations. This is very useful for a calibration technician, because temperature calibrations are very often accompanied with a need to perform also pressure calibrations. In practice, there can be either a multivariable process transmitter which measures both temperature and pressure, or there can be several distinct temperature or pressure sensing devices which need to be calibrated. With such an external pressure module, the sensors measuring these two quantities can be calibrated with a single arrangement. In prior art, there has not been presented a dry block which would be able to measure or calibrate pressure as well; or at least this has been unheard of. With the presented embodiment, a single arrangement i.e. device is able to measure and calibrate both temperature sensors and pressure sensors; relieving the amount of carrying equipment in the field by the calibrator user. This is a further practical advantage of this embodiment.

[0046] In an embodiment, the arrangement comprises a battery which is internal and rechargeable from 220V mains voltage. Of course, the same functionality may be enabled with using at least two batteries as well. In an embodiment, the battery allows using the various features of the arrangement when the mains voltage is not available for some reason, except for the heating and/or cooling elements (embodied with Peltier elements or resistive heating elements, for instance) which would require the use of the mains voltage because of a higher required power. This means that a desired mode of the arrangement may be used without mains power connection, such as e.g. the measurements by the process calibrator, the field communicator functionality or communication according to the calibration software between the calibrator and the external computer in the control room of the factory. In prior art, dry blocks in the market require a mains AC voltage input as a power supply for every functionality they support. Instead, with the presented embodiment of the invention, all functionalities, except the heaters, may be operated by taking the power from the internal battery. This makes the usage and the workplace selections much more free, because it is not always necessary to find a mains AC 220 V input for the arrangement to work. This gives flexibility for the use situations of the arrangement.

[0047] The arrangement may execute all the performed settings, method steps, measurements, calibrations and data transmissions/receptions by applying a calibration software. The calibration software can work in co-operation with the operations available in a control room, or generally, in an external computer used by e.g. a manager of the measurement/calibration actions. The common calibration software enables calibration processes, where work orders may be supplied by the manager, and received by the process calibrator, where the user can view them on the screen. When the measurements and/or calibrations according to the work order have been completed, the calibration software enables the results to be sent back to the control room (or to other external computer or server). The measurements, savings and data transmissions can be implemented as an automated process, after the measurement scheme and the settings have been input or otherwise selected by the user or the manager. Electronic signatures or passwords can be enabled for user identification, and the transmitted data can also be protected with an appropriate encoding/decoding method for protecting data against data tampering or unauthorized access. When the measurement and/or calibration data is received by the control room equipment, the data can be set for viewing, analysis or storage in an appropriate server. Thus, the results can be accessed later anytime. The advantage of the calibration software is a fully paperless process concerning the calibrations and reporting of the calibration results.

[0048] Concerning different fieldbus protocols, the arrangement may provide all required loop supply and impedances concerning communication according to a given fieldbus protocol. Thus, according to the needed fieldbus protocol, the user may select and activate a desired module relating to the selected fieldbus protocol, and there is no need for extra devices or functional modules in order to communicate from the field.

[0049] The arrangement according to the present invention is provided with a plurality of safety features. The main safe concern arises from large heat which is possible during use of a dry block, and the temperature may be even up to +660° C. In an embodiment, the arrangement may output a red indicator light in the front face or on the screen of the process calibrator or the dry block, which will turn on, when the temperature of the dry block exceeds a predetermined temperature limit indicative dangerously hot measurement unit. In an embodiment, the hot unit may be informed to the user by both giving a red indicator light (e.g. through a LED) on top of the dry block, and additionally on the screen of the process calibrator.

[0050] In an embodiment, the safety features comprise applying an accelerometer in the dry block for detecting an inclination (i.e. tilt) angle of the dry block compared to an upright position. If the inclination angle exceeds a predetermined inclination threshold angle, the arrangement will warn the user that the calibration accuracy can be jeopardized through too large inclination angle. Furthermore, when the threshold is exceeded, also the heating and/or cooling elements can be switched off and a fan of the dry block can be also switched on then. In the rare case of the dry block totally tipping over to its side for some reason, the same actions can be performed: Switch off the heaters and turn on the fan for quick cooling of the device, and thus, the ignition probability of a fire can be minimized.

[0051] In an embodiment, the arrangement may apply a functionality where it may calibrate sensors which are physically short or used in sanitary applications, such as in food, beverage or pharmaceutical industries. Many sensors in sanitary application may comprise a flange. This requires a dedicated type of insert, a very short reference sensor and a flexible cable for that sensor. Then, the cover of the dry block comprises groves meant for the reference sensor cable. This structure allows an accurate calibration of a sensor provided with a flange.

[0052] In an embodiment, the arrangement comprises a possibility to connect the arrangement to an external temperature controller or an external pressure controller. Thereafter, the communication between such entities is enabled. In this way, it is possible to e.g. extend the applicable temperature range if the currently used dry block allows a temperature range not enough for the desired use situation. The use of the external pressure controller allows calibrating e.g. various pressure instruments in the field by using the multifunctional process calibrator.

[0053] In an embodiment, the reference sensors used in the arrangement comprise a memory chip which is configured to store the sensor coefficients. The arrangement is configured to automatically read and use these coefficients when the reference sensor is inserted into the arrangement. This ensures correct temperature measurements each time the measurement is performed. Such a reference temperature sensor can be called as a smart reference temperature sensor. In a further embodiment, the smart reference temperature sensor is implemented as a straight sensor, and in another embodiment, the smart reference temperature sensor is implemented as a bent sensor. The latter embodiment allows convenient calibration of sensors with connection heads.

[0054] A main advantage of the arrangement according to the present invention derives from the fact that the device is a multifunctional tool integrated to a compact solution. Thus, it is a very versatile system. It provides excellent accuracy and metrological performance as well. The arrangement will replace a large number of conventional, and separate single-functioned devices. The arrangement in an embodiment comprises a dry block, a temperature calibrator, an electrical calibrator, a pressure calibrator, a multi-bus field communicator, a loop supply, and a note pad as well, thus providing an extensive number of different functionalities. All this can be implemented in a singular housing, which is well carriable by a worker in the field. The device to be carried thus weighs less and it is easier and more convenient to carry and keep with the worker in the field without e.g. risk of forgetting one of the several required devices. Thus, the integrated arrangement is very practical in industrial use situations in the field, and it has great usability. A multi-bus field communicator provides accessibility with different kinds of instrumentation. Finally, an automated documenting functionality obtained by the calibration software enables a full digitalization of the calibration process, which saves paper, and removes the possibility of missing documents in a paper form in the field. This enhances the usability experience even more.

[0055] It is possible to combine separate features disclosed above and in the dependent claims so that any two or more features are applied in common in the invented arrangement. In an embodiment, there are four main features which are interconnectable with any combination comprising two, three or all of them. These four main features are the digital fieldbus protocols, temperature sensor simulation, pressure measurement and the internal rechargeable battery (or batteries).

[0056] Thus, the present invention is discussed through three different aspects, namely an arrangement, a method and a computer program (and a computer program product, correspondingly), all desired to measure or calibrate at least a temperature sensor with advanced functionalities.

[0057] The present invention is not restricted merely to embodiments presented above, but the present invention may vary within the scope of the claims.