WO2005036115A1

WO2005036115A1 - Contactless temperature measurement

Info

Publication number: WO2005036115A1
Application number: PCT/EP2004/010974
Authority: WO
Inventors: Walter Greutmann; Ronald Stiem
Original assignee: Alcan Technology & Management Ltd.
Priority date: 2003-10-07
Filing date: 2004-10-01
Publication date: 2005-04-21
Also published as: DE10346993A1

Abstract

The invention relates to a temperature measuring device (11) for the contactless measurement of the temperature of objects (16) using a pyrometer (10). Said device is equipped with a calibration unit (20), which automatically calibrates the basic measured values (18) of the pyrometer (10). Said calibration is carried out with the aid of the measured values of a reference sensor (22), which is based on a different measuring principle than that of the pyrometer (10). A thermal element (22) is for example suitable for use as the measuring sensor for the reference temperature measurement. The reference measurement is not carried out continuously but at specific times, for example at regular intervals. The reference sensor (22) can thus be mounted so that it remains mobile. If the pyrometer (10) and the thermal element (22) are displaceably mounted, the object (16) can be measured and calibrated in various sections on its surface.

Description

Non-contact temperature measurement

The invention relates to a temperature measuring device for the contactless measurement of the temperature of objects, with at least one contactless sensor device, in particular an optical sensor device. The invention further relates to a method for operating a contactless temperature measuring device with at least one contactless sensor device, such as in particular a pyrometer device. Furthermore, the invention relates to the use of an automatically calibrating contactless temperature measuring device.

In the context of material processing, particularly in industrial manufacturing processes, it is often necessary to measure the temperature of the workpiece to be processed. Casting, forging, stamping, drawing and extrusion are just a few examples. Maintaining certain temperature limits is often essential for the manufacturing process. This can apply to the manufacturing process on the one hand (eg that an upper limit for the permissible temperatures must be observed, for example because the melting point of the material to be processed must not be reached) but also with regard to the workpiece to be manufactured because high or too low temperature, for example, can lead to internal stresses, poor load behavior or cracks in the surfaces of the workpiece.

Especially in industrial manufacturing processes, the secondary conditions to be observed, which the measuring method must meet, are a problem. On the one hand, the most accurate measurement result should be achieved. Furthermore, relatively high temperatures can often be measured. It is also desirable that the measurement not adversely affect the product to be manufactured. After all, the measurement should also be as low-wear as possible, so that the transducers only have to be replaced rarely or not at all. Finally, the measurement must also take place relatively quickly, and in some processes, such as, for example, in extrusion processes, it can also be carried out on a moving object.

In order to be able to meet these secondary conditions, contactless measuring sensors are mostly used for such temperature measuring tasks. In particular, pyrometric temperature measurement methods have become established.

The pyrometric temperature measurement is carried out using the Planck radiation laws. The total energy emitted by a body in the form of radiation depends on its temperature. However, the Planck law on radiation only applies to ideal black bodies.

Total radiation pyrometers or single-channel pyrometers can be used for such black bodies (or quasi black bodies with an emissivity ε close to 1). Calibration of the pyrometer is not necessary.

In order to determine the temperature of a real body, its emissivity (i.e. the body's radiance) must be known. The emissivity of a body is defined by the quotient of the emitted radiation from the body and the radiation from a black body with the same temperature. The emissivity can be described physically by an emissivity ε acting multiplicatively on the Plank's radiation laws. While an ideal black radiator has an emissivity ε = 1, the emissivity of real bodies is less than 1.

A body with an emissivity ε = ε _CO independent of the wavelength with dε / dλ = 0 is called a gray body. In the case of such a measurement of the total energy of the emitted radiation or the measurement of Energy of a certain spectral range of the emitted radiation a temperature lower than this corresponds to the true temperature of the body. 80 Ratio pyrometers can be used for such gray bodies. With constant ε = ε _CO independent of the wavelength with dε / dλ = 0, the ratio of the measured values P (λι) / P (λ ₂ ) is independent of ε, but dependent on the 85 object temperature T.

Furthermore, in most spectral or single-wavelength pyrometers, the emissivity can be set in order to be able to use such pyrometers for the temperature measurement of gray emitters after carrying out a corresponding calibration.

However, there are also materials whose emissivity ε (λ) depends on the wavelength. The values of ε (λ) usually fluctuate between 0.05 and 0.5. In addition, the emissivity can also depend on the surface itself.

In addition, in the case of such non-gray, “colored” bodies, it is often necessary to take into account the influence of the ambient temperature, since the influence of reflected radiation from the surroundings can no longer be neglected.

In order to reduce the measurement errors in such “colored” radiators, it is known that the radiation intensity is measured at two or more different wavelengths λ and these are combined with one another by means of a suitable mathematical combination. However, pyrometers of this type still have one relatively large measuring errors. It is also known that multi-channel pyrometers are calibrated specifically for the material to be measured. First of all, a manual calibration

115 a series of measuring points was recorded on the corresponding material, whereby in addition to the temperature as supplied by the pyrometer without correction, the actual temperature of the material, which can be determined by a thermocouple or the like. can be determined

120 is included. With this data the dependence of the emissivity on the wavelength ε (λ) can be determined, from which the inverse function f ^-1 can be determined. With this inverse function f ^_1 , based on the raw values of the pyrometer, a corrected temperature can be

125 is calculated and output.

A disadvantage of these devices is that a very high calibration effort is initially required.

130 Furthermore, due to the static correction function f ^1, changes over time in the emissivity ε (λ, t) are not recorded. Such changes in the emission characteristics can be caused, for example, by aging of the surface. It is also, for example, with

135 extrusion presses can cause the ambient radiation to change due to heating of the extrusion press during operation, which typically takes several hours, which in turn has an influence on the measured values of the pyrometer and thus on the measuring accuracy of the temperature measurement

140 solution.

In order to avoid such problems, it has been proposed in some cases to blacken highly reflective bodies, such as, for example, metallic pressed material, before the actual extrusion or 145 extrusion, by partial exposure to a layer of soot, and to measure the infrared radiation emitted by the pressed material on the sooted surfaces. This radiation emanating from the sooty areas speaks approximately of the radiation emitted by a black body.

However, this method is problematic because of the relatively complex coloring of the measurement object with soot and the necessity for the subsequent removal of the soot after the measurement and before the measurement object is processed further.

Knowing the above-mentioned prior art, the inventor set himself the task of

160 To further develop a device for the contactless measurement of the temperature of objects in such a way that it substantially eliminates or at least reduces the problems inherent in the prior art. In particular, the inventor set himself the task of

165 to propose a direction which can be used for as many different materials as possible without prior calibration and which nevertheless delivers measurements that are as accurate as possible. Changes in the background radiation should preferably also be compensated for

170. The inventor has also taken on the task of proposing a method for operating a contactless temperature measuring device which has similar advantages. Finally, the inventor has set itself the task of advantageous uses of the method mentioned

175 or to propose the device mentioned.

The teaching of the independent claims leads to the solution of the task; the subclaims indicate favorable further training. In addition, all combinations are within the scope of the invention.

180 tions from at least two of the features disclosed in the description, the drawing and / or the claims. For the specified design ranges, values within the stated limits should also be disclosed as limit values and can be used as desired. It is proposed that a temperature measuring device for the contactless measurement of the temperature of objects, with at least one contactless sensor device, in particular an optical sensor device, be further developed.

190 that at least one automatic calibration device is provided for calibrating the contactless sensor device (s), the automatic calibration device having at least one reference sensor device which is compared to at least one of the contactless sensor devices.

195 tactless sensor devices based on a different measuring principle. The actual temperature measurement can thus be carried out similarly to a conventional pyrometer with an optical sensor device which, for example, has one or more measured values in the infrared spectrum

200 records. The main measuring sensor can thus have the known advantages of contactless sensor devices, such as a fast, contactless and wear-free measurement. In contrast to known measuring devices, however, the contactless is calibrated

205 Sensor device (s) by an automatic calibration device, so that the (corrected) measured values output by the temperature measuring device can largely correspond to the actual temperatures of the measured objects. The automatic calibration takes place

210 preferably in such a way that as many, particularly preferably essentially all, sources of error are compensated for, especially those that have a large influence. For example, surface aging of the object to be measured, a change in the

215 material composition or a change in the background radiation. The automatic calibration can be carried out continuously, for example essentially continuously or at certain time intervals. It is also conceivable that an automatic potash

220 is carried out only after a manual request, it being conceivable in particular that the reference sensor device (for example a thermocouple) is guided by hand to the object to be measured. par- when the reference sensor device is guided by hand

225, a calibration button can be attached directly to the housing of the reference sensor device, for example, so that the user guiding the reference sensor device can carry out the calibration particularly easily.

230 The reference measurement values required for the automatic calibration are made available to the calibration device by at least one reference sensor device. The reference sensor device is based at least

235 compared to one of the contactless sensor devices on a different measuring principle. It makes sense here if the different measuring principle has a lower sensitivity to potential sources of error, is sensitive to other influencing variables, or to

240 potential sources of error reacted to varying degrees sensitively. The individual sources of error can be at least partially eliminated from the measured values by a suitable combination of the main measured value / main measured values and the reference measured value / reference measured values

245, so that the temperature measuring device outputs a temperature value that has a lower error.

The reference sensor device can possibly be based on a 250 measuring principle, which works more slowly, is subject to wear, adversely affects the body to be measured, etc. This is possible because the reference sensor device does not have to deliver measured values continuously, but only, for example, at fixed intervals. 255, the best possible compromise between the best possible calibration on the one hand and the lowest possible reference measurement effort on the other hand is to be sought. Of course, it is also possible that, for example, the time intervals between two reference measurements are selected to be of different sizes. For example, these can be closer together when the device is switched on for the first time. which lie, or can be chosen to be closer together if the required calibration adjustment between two calibration steps is relatively large. in the

In an extreme case, it is conceivable that the automatic calibration, for example after a certain period of time or after a certain quality of the correction function has been reached, will only carry out a reference measurement extremely rarely or not at all. It is also possible to set the time intervals in

270 depending on the required accuracy.

If the contactless sensor device is designed as a pyrometer device, in particular as a ratio pyrometer device and / or as a multi-wavelength pyrometer device.

275 det, commercially available standard components can be used, which can be advantageous, for example, with regard to the cost of the device. Furthermore, compensation methods that may be present in the pyrometers (for example in the case of multi-wavelength

280 meters and ratio pyrometers) can be used, so that the effort for the automatic calibration device can be lower or a more accurate measurement value can be achieved.

285 It is advantageous if at least one automatic calibration device has at least one programmable logic controller. Relatively complex mathematical models for calibrating the contactless sensor inputs can also be used with such generally computer-based controls.

290 directions can be used without unnecessarily driving up costs. Due to the program control, it is also possible to carry out an optimization for certain task purposes by means of appropriately adapted programs. The import of an improved or improved

295 fitted calibration program is particularly easy using an "update". If at least one automatic calibration device is a storage device for storing calibration

300 data, it is possible, for example, for calibration data to be temporarily stored, and so, for example, to switch back to a previous calibration after the device has been switched on again, so that the temperature measurement device has settled.

305 which can be done quickly. The storage device can also be fed with certain standard values, for example in a delivery state of the temperature measuring device. It is also conceivable that, for example, standard values for various industrial processes

310 commonly used materials such as metals or metal alloys are fed in, whereby the user can select a data set that seems suitable to him as a starting value. For example, when using the temperature measuring device in an aluminum

315 Select the extrusion press as the material aluminum or a suitable aluminum alloy so that the starting value is a relatively well approximated data set from which the automatic calibration takes place. This usually takes place relatively quickly, so that u. a. a reduced

320th committee can be achieved.

It is possible that at least one reference sensor device is designed as a contact-type sensor device. Contact-based measurement methods are usually from

325 structure particularly easy to implement. In addition, they are based on a completely different measuring principle as non-contact sensors. In particular, contact-based measurement methods generally have no or a reduced influence on the surface, in particular on the

330 optical properties of the surface of the body to be measured. As a result, the (potential) measurement errors that occur differ greatly from one another, so that the (potential) measurement errors can be largely compensated for.

335 In particular, it is possible that at least one reference sensor device with contacts is designed as a thermocouple. Thermocouples are standard components and deliver a very precise one in a relatively short time

340 reading. The measurement can be carried out by simply placing the thermal sensor on the surface of the body to be measured, so that the measurement can be carried out relatively gently for the body to be measured. In addition, the measurement result for thermocouples in the form of electrical

345 signals, so that the measurement result can be processed particularly easily, for example, by a programmable logic controller.

It can prove advantageous if at least one

350 contactless sensor device, at least one reference sensor device, or a plurality of these are movable in at least one direction, preferably in at least two directions, in particular displaceably and / or rotatably. Such training can make it possible

355 it becomes clear that, for example, with a moving body to be measured (as is the case, for example, with extrusion processes), the area of the surface to be measured can be the same over a certain period of time. This can be particularly the case with a contact

360th measurement method can be of great advantage, since it can avoid scratching the surface of the body to be measured. If both the contactless sensor device and the reference sensor device are movably mounted, both can be used over a longer period of time

365 measure the same area of the surface of the body to be measured. As an alternative to the feed direction mentioned, or in addition to this, the movement can take place in a direction perpendicular to it, for example. If the contactless sensor device and / or the reference sensor

370 can be pivoted in such a direction perpendicular to the extrusion direction, a temperature measurement can be carried out across the profile width of the extruded body. This means that for example temperature or surface differences

375 to the edge of the extruded profile. In the extrusion method mentioned as an example, the calibration can only take place along a profile area (e.g. if the reference sensor device is not movable perpendicular to the extrusion direction), or

380 but also along a plurality of profile areas of the extruded profile. In the latter case, different surfaces, which can arise due to extrusion effects, can also be taken into account in the calibration. In any case, a particularly good one

385 calibration are made possible, especially if these are combined with one another, since any local temperature fluctuations that may be present in the body to be measured need not have a disadvantageous effect on the measurement result. The moveable bearing can, for example, be

390 ren, which cause a pivoting movement or a longitudinal movement of the respective sensor can be realized. With stepper motors of this type, targeted control is also particularly simple. In this context it should be noted that depending on the location of the

395 area on the profile measured by the contactless sensor device (for example in an extrusion process depending on whether the area lies in the middle of the extruded profile or on its side) a different calibration function f ^"1 for calibration

400 of the measurement data can be used.

It is also advantageous if at least one optical control device is provided for checking the agreement of measured values. For example, on a

405 contactless sensor device, a laser pointer can be attached as an adjustment aid such that the light spot marks the area of the body to be measured in which the contactless sensor device records the measured value. For example, if the light spot is near the

410 surface area in which the reference sensor device (e.g. a thermocouple) takes the measurement, be made sure that the respective measured values come from the same surface area of the body. Of course, care should be taken to ensure that the light possibly emitted by the 415 optical control device does not adversely affect the measurement.

In the proposed method for operating a contactless temperature measuring device with at least one

420 contactless sensor device, such as in particular a pyrometer device, there is an automatic calibration of at least one contactless sensor device. Here, too, the automatic calibration enables a particularly good measured value that contains the largest possible number of error

425 sources can be compensated or their influence reduced without the need for time-consuming manual calibration.

It is also advantageous if the automatic calibration 430 takes place essentially continuously and / or at defined intervals.

The automatic calibration is preferably based on at least one reference measurement, which is based on a different measuring principle from that on which at least one of the contactless sensor devices is based.

At least one reference measurement is preferably carried out in the form of a contact measurement, in particular by means of 440 a thermocouple.

It has proven to be advantageous if the location of the temperature measurement, in particular the location of the contact-related temperature measurement, takes place at least temporarily in a constant area of the body to be measured and / or different surface areas of the body to be measured are recorded. In this sense, “different surface areas” are to be understood in particular as those surface areas which, owing to their different positions 450 and / or training can usually provide different measured values. For example, middle areas and lateral areas of the extruded profile can be understood as "different surface areas" in this sense in an extrusion process.

455 The proposed method and the further developments of the same have the properties and advantages described in connection with the device in an analogous manner.

460 Furthermore, the use of an automatically calibrating contactless temperature measuring device for measuring the temperature of objects and / or materials with a wavelength-dependent emission behavior

465 and / or a low emissivity. A temperature measuring device of the type described above is particularly suitable for this use. An emissivity of ε <x is to be regarded in particular as a low emissivity, where x is for example the numerical values 0.1, 0.2,

470 can take 0.3, 0.4 or 0.5. With such materials in particular, known temperature measuring devices only provide relatively poor measured values. The proposed temperature measuring device can bring out its system-specific advantages particularly well here.

475 The self-calibrating contactless temperature measuring device is particularly advantageous, in particular the self-calibrating temperature measuring device proposed above for measuring metallic materials.

480 materials, such as in particular aluminum, copper or gold, and alloys containing at least one of these metals are used. Metals usually have a very low emissivity, as well as a strongly "colored" emission characteristic (λ). This means that it can also do this automatically

485 calibrating contactless temperature measuring device can be used particularly advantageously. It is also advantageous if a self-calibrating contactless temperature measuring device, in particular

490 of the aforementioned type, for temperature measurement in forming processes, such as is used in particular in extrusion processes. With these processes it is generally possible to avoid products of reduced quality and to increase the production speed.

495 made precise temperature measurement particularly important. In addition, the proposed device can be used particularly advantageously because z. B. usually move the body to be measured in extrusion.

500

500 Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing; this shows in:

505 Fig. 1: a schematic view of the control system of a temperature measuring device according to an embodiment of the invention;

510 FIG. 2: a schematic view of the structure of a temperature measuring device according to a further exemplary embodiment of the invention;

FIG. 3: the temperature measuring device shown in FIG. 2 at different times in a simplified representation.

1 shows the schematic structure of a control system 11 according to an embodiment of the invention, 520, which explains the basic principle of the proposed automatic calibration.

As a contactless sensor for temperature measurement, which takes over the continuous part of the temperature measurement, and

525 whose measured values are to be compensated is used by an infrared camera 10 known per se. This infrared camera 10 has an objective 12 which images a specific area of the surface of the body 16 to be measured. In the present example, the infrared camera 10 measures one or more

530 wavelength ranges of the infrared radiation 14 emanating from the body 16 to be measured. The uncalibrated temperature values 18 recorded by the infrared camera 10 arrive via an appropriate data line at an evaluation system 20 which, among other things, has the calibration logic.

535 In addition to the infrared camera 10, a reference sensor based on a different measuring principle, in the present example a thermocouple 22, is provided, which measures essentially the same surface area of the body 16 to be measured. The measuring ranges of the infrared camera 10 and the thermocouple 22 are matched to one another in such a way that the measurements are not mutually obstructed.

The reference temperature values 24 determined by the thermocouple 22 are likewise transmitted to the evaluation system 20 via a corresponding data line. The evaluation system 20 compares the continuously incoming uncalibrated temperature values 18 with the reference temperature values 24 arriving in intervals, for example, and determines a compensation function for the uncalibrated temperature values 18 coming from the infrared camera 10. The temperature values 26 calibrated with the aid of the compensation function are transmitted to an interface 28 via data lines from which these can be read. The interface 28 can be, for example, an interface 28 for a person in the form of a display device, or else (possibly in parallel with it) a known computer interface such as, for example, B. RS232, V24, USB, etc. act so that the calibrated temperature values 26 provided at the interface 28 can be read particularly easily by a computer. In addition, it is possible for the evaluation system 20 to send control signals 30, for example to an adjustable holder of the thermocouple 22, via a control line. In the present example, the time interval between two reference measurements is reduced if a larger drift of the compensation function is determined between two successive reference measurements of the thermocouple 22. By reducing the time interval, the error of the calibrated temperature values 26 can be reduced, in particular for the temperature values immediately before the next reference measurement. 575 Conversely, it is of course also possible for the time intervals between two reference measurements to be increased if the drift of the compensation function is only slight.

580 FIG. 2 shows an exemplary embodiment of the invention in which, similar to FIG. 1, the contactless sensor device is in the form of an infrared camera 10 and the reference sensor device is in the form of a thermocouple 22. Both infrared camera 10 and thermal

585 element 22 are movably arranged in the exemplary embodiment shown in FIG. 2 and can be moved in a targeted manner by stepper motors 32, 33, for example by the evaluation system 20 or other control logic.

590 In the present example, the body to be measured is an extruded profile 34, a section of which is shown in FIG. 2. As indicated by the arrow labeled x, the extruded profile 34 moves in this direction.

595 The measurement setup shown in FIG. 2, consisting of infrared camera 10 and thermocouple 22, is intended to measure an area L on the upper side 35 of the extruded profile 34. Due to the movement of the extruded profile 34 in

600 the arrow direction of x, the surface area L of the extruded profile 34 to be measured shifts to the same extent. In order to compensate for this movement, the thermocouple 22 is mounted on a linear drive 36, so that the thermocouple 22 is inserted into the

605 can be shifted by the double arrow a indicated longitudinal direction. In addition, the thermocouple 22 can be brought into contact with the surface 35 of the extruded profile 36 by means of a servomotor, which is not shown here, or can be lifted off the latter.

610 In the exemplary embodiment shown in FIG. 2, the infrared camera 10 is rotatably fastened and can be pivoted in the pivoting direction indicated by the double arrow b by a further stepper motor 32. The one in

615 different spacing between the infrared camera 10 and the surface area L of the extruded profile 34 which is traveling and is to be measured in the direction of the arrow x can be compensated for by a controlled readjustment of the objective 12.

620 The opening angle of the lens 12 can also be adjusted.

Even if this is not shown in more detail in the figure, the infrared camera 10 and the thermocouple 22 can

625 can also be moved in a direction t perpendicular to the extrusion direction x. As a result, different temperatures and surface characteristics along the direction t running perpendicular to the extrusion direction x can also be taken into account in the compensation.

630 The correction function therefore depends not only on the emitted radiation from the extruded profile 34, but also on the geometric location t.

3 shows the measuring system 38 shown in FIG. 2 at 635 different times, the drive elements not being shown for reasons of clarity.

3a shows the normal state of the measuring system 38. A 640 temperature measurement is carried out continuously using the infrared camera 10, which is in a neutral position. The thermocouple 22 is in a retracted normal position in which it does not touch the surface 35 of the extruded profile 34. In a leveled-out state of the measuring system 38, it is in the normal position shown in FIG. 3a for most of the time. After a certain time interval has elapsed, a reference measurement cycle is initiated. The situation at the beginning of the reference measurement cycle is illustrated in Fig. 3b. The thermocouple 22 is moved downward in the direction yi and makes contact with the surface 35 of the extruded profile 34. In order to be able to deliver a measured value, the thermocouple 655 element 22 requires a specific setting time period of typically a few seconds. During this time, as illustrated in FIG. 3b, the thermocouple 22 is moved in the x direction in synchronization with the extruded profile 34. So that the 660 surface areas L of the extruded profile 34 measured by the thermocouple 22 and the infrared camera 10 essentially coincide, the infrared camera 10 is pivoted synchronously with the movement x of the extruded profile 34, which is indicated by the arrow zi.

665 When the temperature reference value is determined using the thermocouple 22, the thermocouple 22 is lifted in the direction y ₂ from the surface 35 of the extruded profile 34, as indicated in FIG. 3c. The thermocouple 22 then moves in the opposite direction to the direction of travel

670 x of the extruded profile 34 in the direction y _{3 back} to the neutral position shown in Fig. 3a. The infrared camera 10 is also moved back into its neutral position according to FIG. 3a, which is indicated by the arrow z ₂ . It is possible that the reset movement z _{2 of} the infrared camera

675 10 runs particularly slowly, so that the infrared camera 10 has enough time to continuously determine temperature measured values of the surface 35 of the extruded profile 34 during its resetting movement z ₂ .

680

Claims

680 PATENT CLAIMS

1. Temperature measuring device (11, 38) for contactless measurement of the temperature of objects (16, 34), with

685 at least one contactless sensor device (10), in particular an optical sensor device, characterized by at least one automatic calibration device (20) for calibrating the contactless sensor device

690 device (s) (10), the automatic calibration device having at least one reference sensor device (22), which is based on a different measuring principle compared to at least one of the contactless sensor devices (10).

695 2. Temperature measuring device according to claim 1, in which at least one contactless sensor device as a pyrometer device (10), in particular as a ratio pyrometer device and / or as a multi-wavelength

700 gene pyrometer device is formed.

3. Temperature measuring device according to one of claims 1 or 2, characterized in that at least one automatic calibration device (20) at least

705 has a programmable logic controller.

4. Temperature measuring device according to one of claims 1 to 3, characterized in that at least one automatic calibration device (20) a memory

710 device for storing calibration data.

5. Temperature measuring device according to one of claims 1 to 4, characterized in that at least one

715 reference sensor device is designed as a contact sensor device (22).

6. Temperature measuring device according to claim 5, characterized in that at least one contact

720 reference sensor device is designed as a thermocouple (22).

7. Temperature measuring device according to one of claims 1 to 6, characterized in that at least one

725 contactless sensor device (10) and / or at least one reference sensor device (22) are mounted in at least one direction, preferably in at least two directions, in particular displaceably (a) and / or rotatably (b).

730 Temperature measuring device according to one of claims 1 to 7, characterized by at least one optical control device for checking the conformity of measuring locations.

735 9. Method for operating a contactless temperature measuring device (11, 38) with at least one contactless sensor device (10), such as in particular a pyrometer device, characterized in that

740 that an automatic calibration (20) of at least one contactless sensor device takes place.

10. The method according to claim 9, characterized in that the automatic calibration essentially

745 takes place continuously and / or at defined intervals.

11. The method according to claim 9 or 10, characterized in that the automatic calibration on we-

750 is based at least on one reference measurement (22), which is based on a different measurement principle such as that of at least one of the contactless sensor device (10).

12. The method according to any one of claims 9 to 11, characterized in 755 that at least one reference measurement in the form of a contact measurement, in particular by a thermocouple (22), takes place.

13. The method according to any one of claims 9 to 12, characterized 760 that the location (L) of the temperature measurement (22), in particular the location (L) of the contact-related temperature measurement, at least temporarily in a constant area of the body to be measured (34) takes place and / or different surface areas

765 of the body (34) to be measured.

14. Use of an automatically calibrating contactless temperature measuring device, in particular a temperature measuring device according to one of the claims.

770 before 1 to 8, for measuring the temperature of objects and / or materials with a wavelength-dependent emission behavior and / or a small emissivity.

775 15. Use according to claim 14 for measuring the temperature of metallic materials, in particular aluminum, copper or gold, and alloys containing at least one of these metals.

780 16. Use of an automatically calibrating contactless temperature measuring device, in particular in addition to a use according to claim 14 or 15, for the temperature measurement in forming processes such as, in particular, extrusion processes.

785