DE102006026920B4 - Device for the suppression of measured value distorting radiation components in non-contact IR measuring devices in high-temperature furnaces - Google Patents

Abstract

contraption for suppression distorting from reading Radiation shares in non-contact working infrared radiation measuring devices in high-temperature furnaces, the between the infrared radiation measuring device (15) and the measuring object (1) in the smallest possible Distance (a) to the measurement object (1) is arranged without contact, with a arranged in the beam path, tubular shielding (2) with a sequence transverse to the beam path spaced Abschirmschilde (4) with central beam ports for eliminating overlays the measurement object radiation not belonging to the measurement object's own radiation, the inner walls (20) of the tubular Shielding system (2) together with the Abschirmschilden (4) a plurality Coaxially arranged radiation absorption chambers (5) form, thereby characterized in that the tubular interior walls (20) the radiation absorption chambers (5) in the direction of the infrared radiation measuring device (15) oblique to run inwards with an angle α> 0 °, so that after Reflections in the absorption chambers (5) resulting Strahlungsaustrittswinkelγ always greater than is the radiation entrance angle β.

Description

The The invention relates to a device for use in non-contact Temperature measurements by radiation pyrometry or thermographic Image recordings or measurements of the spectral emittance by means of Spectroscopy, in the infrared wavelength range of surface radiation a measurement object. For example, the measurement object is a moving one or non-moving solid infrared radiopaque body in a high temperature oven with typically more than 500 ° C oven internal temperature, at which the surface temperature this body based on the emitted infrared radiation contactless, For example, by using a pyrometer, is measured.

A device for the suppression of measured value distorting radiation components with the features of the preamble of claim 1, but provided for another application is known from EP 0 708 318 A1 known.

It It is known that the direct from a test object in a high-temperature furnace outgoing infrared radiation from radiation components that have their origin in the measuring object environment in the furnace interior, can be superimposed and this Radiation shares in the vast majority practical applications the objective of a selective and as accurate as possible contactless Counteract measurement of the measurement object radiation. Practical examinations at high-temperature furnaces The industry has shown that often considerable incalculable Temperature error measurements arise. The radiation components mentioned have their origin in the emanations of those objects that surrounded the actual measurement object and generally as ambient radiation of the object to be measured. Is the measurement object located? inside a high-temperature furnace, so for example, can be mounted inside Heating elements that are hot interior walls or a flame may be such objects, with mostly each radiator for themselves or every subarea in this environment a temperature which is different from the object to be measured is usually higher and may have a different emission coefficient. The environment can also be done, such as in intermediate oven cooling zones, consist of surrounding infrared radiating objects, which are predominantly have a lower temperature than the measuring object itself in practical cases mostly inhomogeneous directional and intensity-dependent ambient radiation meets the object to be measured and is partially reflected there and partially absorbed.

The Radiation components reflected from the test object environment on the test object or the directly directed from surrounding objects Ambient radiation superimposed partially and directionally with the direct measurement object's own radiation. Get this superimposed reading falsifying Radiation shares in the mouth the beam path facing the measurement object and consists of this beam path input area and the thereon immediately follow the zones of the beam path, as from existing practical technical construction known her only from an inside smooth and mostly for Infrared radiation well reflective pipe, so they go unhindered to the meter and usually cause serious measurement errors.

State of the art

One called tube with smooth inner walls called the sight tube is from the product range (Prospectus No. S4M100G / 119) of LAND Instruments GmbH, 51381 Leverkusen, known. For example, these are often used in high-temperature furnaces, heating chambers and at higher Ambient temperatures used. Sight tubes preferably find Use for viewing the measuring spot on the measuring object surface Steam, smoke and flames etc. It should be noted that in applications with additional cooling the smooth interior walls this primarily for reducing the intensity of secondary radiation serves, that is the temperature-dependent Own radiation of these inner walls, on a relative to the temperature and radiation of the measured object low level and thus the significant reduction in the Own radiation of the inner walls caused measurement errors.

In most practical applications of a non-contact working infrared radiation measuring device are already in Input range of a beam path Measurement value of distorting radiation components in front.

Thereby requires no device or structure inside the beam path input area present, which already causes in the area near the measurement object, that the superimposed Radiation components of the emitted direct radiation from the object to be measured be separated or this measured value falsifying radiation components repressed be leads to that this superimposed reading falsifying Radiation shares almost unhindered to that at the other end of the beam path located infrared measuring device reach.

In a connected infrared radiation measuring device, such as a pyrometer, it is then no longer possible, the received from different sources of radiation Meßobjektumgebung superimposed infrared radiation from the actual direct measurement objects to be measured to distinguish radiation. The resulting and mostly not insignificant temperature measurement error is mainly dependent on the temperature difference between the measurement object and the radiation sources of the measurement object environment and on the size of the emission or reflection coefficient of the measurement object. These variables determining the temperature measuring error are mostly of a temporary nature, that is to say that, for example, the temperature of the surrounding heating radiators and the temperature of the surrounding walls change during the technological process.

Around the adulteration of the measured values by the measured values which distort the radiation To minimize or eliminate significantly, in particular Range of pyrometric temperature measurement various methods and Devices have become known.

at some are mostly complicated mathematical evaluation methods, where from a variety of radiation measurements, known Boundary conditions and necessary assumptions about the state of the DUT surrounding infrared radiating objects for determining the temperature of the measured object is used. These procedures are however too inaccurate and for dynamic processes, for example, with the change of surface properties on moving objects or with changes in ambient radiation go along, completely unusable.

Furthermore, from the US-A-2,611,541 a measuring arrangement is known in which in principle in the immediate vicinity of the measuring spot on the measuring object surface as evenly as possible radiated matched ambient radiator with a known temperature is extra attached. In this case, an approximately constant ambient radiation is provided whose radiator temperature is known and is used in a specific way to compensate for the measurement errors. This solution is characterized by great effort and is difficult to integrate into existing technical systems.

From the EP 0 708 318 A1 For example, a system for determining the temperature of wafers for semiconductor fabrication is known. This invention relates to non-contact measurement of the radiation of an object in a radiation environment, such as a semiconductor wafer in a RTP chamber, and to determine the temperature of the object by utilizing the radiance measurement plus a sub-measure of the emissivity of that object. The "background radiation" (background radiation, ambient radiation) superimposed during the radiance measurement is largely eliminated by using spatial and angular filtering, starting with problems with the ambient radiation of the measurement object (wafer) which is surrounded by heating elements / lamps in a chamber The illustration is a combined multiple measurement and calculation, pulsed laser measurement and control of the heating elements.

to suppression the measured object ambient radiation in the radiance measurement becomes a elongated angle filter assembly used. It consists, as shown, of a set of simple connected in series pinholes, in which the radiation of the Ambient radiator suppressed becomes. This simple design of an angle filter assembly is for use in high-temperature furnaces not suitable. At the for Suitable for high-temperature furnaces Dimensions of this assembly will be the shielding effect for reading falsifying Radiation shares significantly lower than this, as stated the inventor with smaller dimensions and the geometric Arrangement, with the observation of a small spot and available Small diameter of the free beam passage in radiation measurements on wafers. It's in high-temperature furnaces too much higher Duration radiation intensities to expect from a few kW. This in turn requires that it be in the shielding used reinforced opportunities for adequate Number of reflections and associated energy absorption for the Falsifying the measured value Radiation shares and a sufficient cooling would have to give. at the simple parallel arrangement of the pinhole is the well-known adverse effect that the size of the entrance angle of a Radiation in the aperture interspaces equal to the exit angle is and therefore larger leftovers distort the measured value Radiation can enter the infrared radiation measuring device. That such simple systems only a relatively low shielding effect own, is already known from experiments on high-temperature furnaces.

Furthermore, an arrangement of an inner shielding body in an infrared radiation device of the DE 3716358 C2 known. It is the object of this patent to provide a device, in particular for the suppression of infrared interference of the meter housing and its lens frame to create. The among others from the EP 0 708 318 A1 already known shielding body is arranged near the detector of the measuring device. For physical reasons, it is no longer possible with this invention to separate the superimposition already formed close to the measurement object between the measurement object intrinsic radiation and the measured value of the ambient radiation of the measurement object. The measuring device is placed away from the measuring object. The disturbing intrinsic radiation of a measuring device or its immediate surroundings For the most part, exercise is not associated with the radiation from the surroundings of the measurement object.

Further, another development is based on the AT 390 326 B on the use of a pulsed auxiliary radiator, which periodically changes the temperature of the test object in the region of the measuring spot by less than 1 K, that is, the surface temperature is increased periodically in the region of the measuring spot and lowered again by heat conduction and radiation. The temperature is measured by means of a synchronous to the auxiliary radiator frequency measuring ratio pyrometer. In this method, only the alternating components emitted by the measurement object at the measurement spot are used for temperature measurement. Messwertverfälschende radiation fractions, which arise as mentioned above and can get over the beam path to the pyrometer, are not modulated radiation components and are not taken into account in the evaluation. The disadvantage of this solution is that in this method immobile objects must be present. For example, according to this method, the measurement of the surface temperature of a moving steel strip is not possible because of the constant change of the surface in the region of the measuring spot.

at Another method is to reduce the influence distorting from reading Radiation components on the temperature measurement, for example, two Pyrometer used, with the first pyrometer, the radiation of the measured object measures and the second pyrometer measures the radiation from a selected area of the Measurement object environment. From the signals of both pyrometer measurements becomes the temperature of the measured object is determined. In this process are size Temperature measurement error expected, because it is assumed that the temperatures of the surrounding radiating objects are constant and the values of reflection, absorption and emission both at Measured object as well as remain constant with the objects of the environment. For example, the method is typical for dynamic ones Heating processes, with changing temperatures in radiant heaters and DUT and changing Emission coefficient, because of the expected large temperature measurement error not suitable.

A distorting others for the purpose of reducing the influence of reading Radiation components used on the temperature measurement device consists of a cooled Sight tube with smooth inner surfaces, around its mouth in addition a connected to the sight tube and usually circular also chilled Shield is attached, is from the report no. EUR 20463 EN, ISBN 92-894-4237-9, 2002, p. 107 46, 87, European Commission / Steel Research known. The sight tube is close together with shield the target surface arranged inside a high temperature furnace without touching it. It there is a necessary and mostly small gap, the safe non-contact measuring object movement parallel to the shielding surface allows. By means of this shield, in the middle of which the mouth of the Sight tube is a shield of the measuring spot environment achieved on the measuring object, so that the radiation of the surrounding objects can no longer hit the spot spot environment directly; short Reflection paths to the mouth the sight tube are not possible.

Yet continue to get shares of ambient radiation by multiple Reflections between the shield and the object to be measured in the beam path and thus to the infrared radiation measuring device.

at Use of a small shield or at too great a distance the object of measurement is the effect of shielding the ambient radiation insufficient. On the other hand, large diameter shields require at the location complex construction measures. When used in High-temperature furnaces This is usually also energetically opposite to the heating process a not inconsiderable cooling performed.

task It is the object of the present invention to provide a device for use at non-contact Temperature measurements by radiation pyrometry or thermographic Image recordings or measurements of the spectral emittance by means of Infrared spectroscopy, with which the directly from the Measurement object derived measuring value falsifying radiation components as close as possible to the measurement object be completely eliminated. The particular by these radiation components removed at one at the other end of the associated beam path attached infrared radiation measuring device commonly evoked Measurement errors should not occur by using this device can arise. The device is intended to meet the aforementioned disadvantages with regard to applicability do not have and for the Use in harsh and extreme industrial environments, typically within high temperature furnaces, at ambient temperatures of 500 ° C and more, be suitable. The device is intended in particular by an advantageous compact design be integrable in existing infrared measuring devices.

This object is achieved with features of claim 1. The device according to the invention contains in its interior a tubular, advantageously profiled shielding system. This consists of several successively coaxial angeord Neten and cooled or regulated tempered radiation absorption chambers and Abschirmschilden and this device is arranged without contact between the infrared radiation measuring device and the measurement object in the smallest possible distance from the measurement object. Due to the special shape and dimensioning of the radiation absorption chambers and shielding shields, a radiation angle change to other radiation absorption chambers is always effected by the infra-red measuring device resulting in a substantial increase in the number of reflections associated with the reduction of radiation intensity , which leads to an elimination of these measured value distorting radiation components. At the same time, almost exclusively only the directly emitted radiation components corresponding to the actual infrared radiation of the measurement object are transmitted through this device, so that only these unadulterated radiation components reach the remotely mounted infrared radiation measuring device and its measured values consequently correspond substantially more precisely to the actual measurement object intrinsic radiation.

By the bevel the cylinder jacket inner surfaces of the absorption chambers, the number of reflections is the reading falsifying Radiation shares significantly increased and thus essentially absorbed.

advantageous Embodiments of this device according to the invention are in the dependent claims 2 to 11 indicated.

invention exposition

following the invention will be with reference to the accompanying drawings based on a preferred embodiment explained in detail. It shows

1 a schematic sectional view of the sight tube SR with inner shielding system, in an arrangement with the measurement object and connected infrared radiation measuring device;

2 a schematic detail to 1 with radiation absorption chamber and two shields as part of the inner shielding system and an exemplary representation of the reflections and deflection of infrared radiation in the radiation absorption chamber.

This in 1 shown sight tube (SR) with inner shielding system ( 2 ) is arranged so that the distance (a) to the surface of the measurement object ( 1 ) is kept as small as possible, but does not come into contact with this surface. The measuring object ( 1 ) may be, for example, both a dormant and a solid non-infrared radiopaque body moving past the sight tube entrance.

at moving measuring objects, for example heated steel strips in the High temperature furnace in a rolling mill, becomes the minimum distance by deviant movement of the band and by other technical Requirements limited. A touch The sight tube (SR) with the passing band must be excluded become.

This in 1 shown sight tube (SR) with inner shielding system ( 2 ) is arranged so that its optical axis ( 13 ) perpendicular to the surface of the measurement object ( 1 ), wherein for the measurement object ( 1 ) is predetermined, that it is not infrared radiation permeable and has sufficiently large dimensions to avoid direct irradiation from the Meßobjekthintergrund in the sight tube entrance.

In this arrangement close to the measuring object of the sight tube (SR) with inner shielding system (FIG. 2 ), only the own radiation of the test object ( 1 ), exemplified by measurement object intrinsic radiation ( 11 ) and the object to be measured ( 1 ) reflected radiation, exemplified by the reflection of the ambient radiation ( 12 ), to the entrance of the sight tube (SR). The ambient radiation ( 12 ) may, for example, from the surface of a radiant heater for heating steel strip in Hochtempe temperature furnace, wherein such a radiant heater has a higher temperature than the measured object steel strip.

The above-mentioned measured value falsifying radiation components arise, illustrated by the example 1 , with the reflection of the ambient radiation ( 12 ) on the test object ( 1 ). The beam representation of a single ambient radiator ( 12 ) is a simplification of the presentation 1 , Real measurement object environments may consist of a plurality of ambient radiators, wherein their beam direction and the angle of incidence may be very different in their reflection at the measurement object near the measurement spot,

It should be emphasized that, because of the arrangement of the viewing tube (SR) close to the object of measurement, the radiation originating from the measuring object environment can only ever reach the viewing tube entrance with radiation directions that differ substantially from the direction of the measuring object surface normal. An example of this is the radiation of a single ambient radiator ( 12 ), which after a single reflection on the measurement object ( 1 ) "Obliquely" into the entrance (mouth) of the sight tube (SR) arrives.

The sight tube (SR) consists in its inner core of a shielding system ( 2 ) with specially shaped and dimensioned and cooled or regulated tempered shields ( 4 ) and radiation absorption chambers ( 5 ) facing the optical axis ( 13 ) is arranged coaxially. The shielding system ( 2 ), consisting of good heat-conducting material, filled with a plurality of circular shield shields arranged one behind the other ( 4 ) and radiation absorption chambers ( 5 ) almost completely the inside of the sight tube (SR). The inner walls of the radiation absorption chambers ( 5 ) have an inwardly inclined conical shape, wherein the diameter of the radiation absorption chamber ( 5 ) to the beam exit opening of the viewing tube (SR) is reduced (see also detailed representation 2 ).

The shielding system ( 2 ) is advantageously designed so that it together with the over the entire length in its outer walls introduced preferably spirally encircling cooling channels ( 3 ) forms a heat-resistant compact unit, the one for the overall function of the sight tube (SR) required good cooling or controlled temperature of the shields ( 4 ) and the walls of the radiation absorption chambers ( 5 ). A the cooling channels ( 3 ) covering and adapted pipe ( 7 ) encloses the shielding system ( 2 ) and separates the in the cooling channels ( 3 ) flowing heat carrier (for example, cooling water) from other areas of the sight tube (SR) and to the outside. The cooling of the shielding system ( 2 ) is designed, for example, that it is advantageously operated in the heat transfer circuit with a recooling system.

Between the outer tubular heat-resistant jacket ( 8th ) of the sight tube (SR) and the inner tube ( 7 ) is a filling of heat-resistant heat insulating material ( 9 ), for example mineral wool. Thus, the sight tube (SR) together with flange ( 6 ) can be used advantageously for installation close to the measurement object in measuring openings with flange and for continuous operation within process engineering systems at high ambient temperatures within high-temperature furnaces.

In the 1 shown beam directions show that only the object to be measured ( 1 ) outgoing portions of the sample object radiation ( 11 ), which extend through parallel or approximately parallel radiation direction to the optical axis (FIG. 13 ) of the sight tube (SR) and the connected connecting tube ( 14 ), unhindered by the imaging optics ( 16 ) to the internal infrared sensor ( 17 ) of the infrared radiation measuring device ( 15 ) reach.

It is known to the person skilled in the art that the device measuring infrared radiation ( 15 ) is a device installed outside of zones with extreme environmental conditions, such as high temperatures in high-temperature furnaces, and is not in the immediate vicinity of the measuring object. The connecting pipe ( 14 ) in 1 substitutes all between the flange ( 6 ) of the usually extreme environmental conditions exposed sight tube (SR) and the infrared radiation measuring device ( 15 ) used structural elements.

The of the optical axis ( 13 ) in the radiation angle substantially different proportions of the Meßobjekteigenstrahlung ( 11 ) and the object to be measured ( 1 ) in the vicinity of the measuring spot reflected "obliquely" incident portions of the ambient radiation ( 12 ) together form an overlapping radiation, the geometrically due to the shields ( 4 ) of the shielding system ( 2 ) or in the radiation absorption chambers ( 5 ).

All the after 1 "Oblique", that is essentially different from the optical axis ( 13 ), in the entrance of the sight tube (SR) incident radiation components are generally measured value distorting radiation components, since it is superimposed radiation from different sources of infrared radiation and these radiation components necessarily reflected on the inner surfaces of the entire beam path and as superimpositions to infrared radiation measuring device ( 15 ) can get.

These measured value falsifying radiation components make due to their off-axis radiation directions on the shield shields ( 4 ) of the shielding system ( 2 ) inside the sight tube (SR) and are on their surfaces and at the oblique walls of the radiation absorption chambers ( 5 ) reflects or absorbs. The measured value distorting radiation components forcibly pass through a high number of successive reflections (reflection points), which, depending on their angle of entry at the sight tube entrance in different sections of the shielding system ( 2 ) and in several adjacent radiation absorption chambers ( 5 ) of the shielding system ( 2 ) respectively. As a rule, with each reflection taking place, part of the radiation energy present is absorbed by the shields ( 4 ) of the shielding system ( 2 ) or the walls of the radiation absorption chambers ( 5 ) absorbed. The absorbed energy is absorbed by the well-conducting material of the shielding system ( 2 ) to the heat transfer medium in the cooling channels ( 3 ) derived.

In 1 is an example of the course of the reflections within the shielding system ( 2 ) for the original ambient radiation ( 12 ) net. For those parts of the sample object radiation ( 11 ), which with their radiation direction on the shielding system ( 2 ) meet, also multiple reflections will come about.

It can be calculated according to how many reflections the initial intensity of an incident measurement value-distorting radiation is reduced to a specific minimum that is required in comparison to the direct radiation of the measurement object and that does not influence more measurement errors. In this case, the required for this minimum number of reflections by both the constructive dimensions of the shielding ( 2 ) as well as by the absorption coefficient of its inner surfaces. For example, the larger the absorption coefficient, the lower the number of required reflections.

The lowering of the energy of the measured value of distorting radiation components to a level which is insignificant for the measurement is also given by the fact that, as a result of sufficient cooling or regulated temperature of these shielding shields ( 4 ) to a constant low value, no additional secondary emitters with measured value falsifying effect can arise. Secondary radiators are surface areas that reach higher temperatures due to the absorption of radiant energy and thus themselves become intense infrared radiation sources.

There is also a mutual and multiple shading by shields ( 4 ) in the shielding system ( 2 ) that makes it impossible for the remotely located infrared radiation measuring device ( 15 ) the reflections taking place in the radiation absorption chambers ( 5 ) Can be "observed".

The following is based on 2 by way of example the representation of the reflections and deflection of infrared radiation in a radiation absorption chamber ( 5 ) explained. 2 is a detailed representation of the rotationally symmetrical shielding system ( 2 ) of the sight tube according to the invention.

In the schematic detail 2 be half-sided two shields ( 4a and 4b ) and the radiation absorption chamber ( 5 ). The centers of shielding shields ( 4a and 4b ) lie on the optical axis ( 13 ). In this half-side sectional view, the radiation absorption chamber ( 5 ) through the lower shield ( 4a ), the spaced above upper shield ( 4b ) and the inclined inner wall ( 20 ) limited. The inclination of the inner wall ( 20 ) is determined by the angle α. It is the shield shield opening ( 4c ) and the shield shield opening ( 4d ). The outer wall ( 7a ) of the shielding system ( 2 ) is shown here without cooling channels.

In 2 is exemplified in the radiation absorption chamber ( 5 ) incident beam ( 8th ) and the reflections taking place on the two shields ( 4a and 4b ) and on the inclined inner wall ( 20 ). The direction of the radiation absorption chamber ( 5 ) incident beam ( 8th ) is characterized by the perpendicular to the entrance angle β and the direction of the radiation from the absorption chamber ( 5 ) after several reflections again emergent beam ( 9 ) by the perpendicular to the vertical outlet angle γ.

Due to the special shape of the radiation absorption chamber ( 5 ) caused by the inclination of the inner wall ( 20 ) is characterized by the angle α, it is achieved that the exit angle γ is always greater than the entry angle β and thereby conditionally the exit jet ( 9 ) always in one of the nearest radiation absorption chambers ( 5 ) of the shielding system ( 2 ) and not on the remote infrared radiation measuring device ( 15 ) is aligned. As a result, subsequent further reflections run in other radiation absorption chambers ( 5 ) of the shielding system ( 2 ) of the sight tube (SR), so that even with a high reflectivity of the surfaces of the shielding ( 2 ) used material, as is the case, for example, in heat-resistant stainless steel, there is always a sufficiently large number of reflections that leads to almost complete degradation of the energy of the measured value distort the radiation components.

In addition, the particular shape of the radiation absorption chamber ( 5 ), that by the principle of the multiplication of the reflections with increasing number of used radiation absorption chambers ( 5 ) and shields ( 4 ) always accompanied by a further increase in the shielding effect.

A highly absorbent additional surface coating of the shields is provided under special measuring conditions. By dividing the number of reflections necessary for sufficient radiation energy absorption into a plurality of radiation absorption chambers ( 5 ), there is also the advantage that the inner diameter of the radiation absorption chambers ( 5 ) can be kept relatively small, with further advantages for the cooling of the shielding system ( 2 ) and for a compact design of the sight tube.

Claims (11)

Device for suppressing measured values of distorting radiation components in non-contact infrared radiation measuring devices in high-temperature furnaces, which are connected between the infrared radiation measuring device ( 15 ) and the measurement object ( 1 ) at the smallest possible distance (a) to the measured object ( 1 ) is arranged without contact, with a arranged in the beam path, tubular shielding system ( 2 ) having a sequence of screening shields arranged at a distance from the beam path ( 4 ) with central beam passage openings for eliminating superpositions of the measurement object radiation which does not belong to the measurement object radiation, wherein the inner walls ( 20 ) of the tubular shielding system ( 2 ) together with the shields ( 4 ) a plurality of coaxially arranged radiation absorption chambers ( 5 ), characterized in that the tubular inner walls ( 20 ) of the radiation absorption chambers ( 5 ) towards the infrared radiation measuring device ( 15 ) run obliquely inwards at an angle α> 0 °, so that after reflections in the absorption chambers ( 5 ) is always greater than the radiation entrance angle β. Device according to claim 1, characterized in that that the angle is α ≤ 20 °. Device according to claim 1 or 2, characterized in that the shielding system ( 2 ) consists of good heat conducting material with correspondingly large values of cross-sectional areas and screening shield thicknesses for good heat dissipation, all its inner surfaces radiant energy receiving surfaces and the outer surfaces of the shielding ( 2 ) integrated cooling channels ( 3 ) for a flowing heat transfer medium for the removal of the absorbed energy, in uniform heat conductive contact with all shields ( 4 ) and cause a homogeneous temperature distribution, so that the temperature of the inner surfaces of the shielding ( 2 ) is maintained at a substantially lower and predetermined temperature compared to the radiation temperature of the measurement object by a controlled heat transfer medium temperature and the formation of measured value of falsifying secondary radiation of the surface elements of the shielding system ( 2 ) even with high thermal energy radiation into the shielding system ( 2 ) and accordingly high energy absorption is prevented. Device according to at least one of claims 1 to 3, characterized in that the shielding system ( 2 ) limiting inner surfaces have a high absorption factor. Device according to at least one of claims 1 to 4, characterized in that the shielding system ( 2 ) are subjected to limiting inner surfaces of a serving for increasing the absorption factor treatment. Device according to at least one of claims 1 to 5, characterized in that all in the shielding system ( 2 ) shielding shields ( 4 ) are arranged parallel to one another and the associated coaxial to the optical axis ( 13 ) shield shield openings ( 4c . 4d ) are circular and have the same diameter. Device according to at least one of claims 1 to 6, characterized in that the radiation absorption chambers ( 5 ) with shielding shields ( 4 ) Fill 85% to 100% of the length of the device. Device according to at least one of claims 1 to 7, characterized in that the tubular shielding system ( 2 ) through a cooling channels ( 3 ) tightly covering and adapted pipe ( 7 ), which is concentrically surrounded by an outer shell made of heat-resistant and corrosion-resistant material ( 8th ), the gap with heat-resistant, heat-insulating material ( 9 ) is filled, so that the functional and reliable use of the device in the vicinity of the measuring object is possible at high ambient temperatures of 500 ° C and more. Device according to at least one of claims 1 to 8, characterized in that on the side of the infrared measuring device ( 15 ) a flange ( 6 ) fitted with the outer shell ( 8th ), the pipe ( 7 ) and the shielding system ( 2 ) is firmly connected and adapted for the connection of external ele ments and contains cooling duct connections. Device according to at least one of claims 1 to 9, characterized in that its radiation inlet opening close of the measurement object according to the rule D / a ≥ 2, where D is the outer diameter of the device and a the distance of the beam entrance opening from the Measuring object is. Device according to at least one of claims 1 to 10, characterized in that its longitudinal axis at an angle of 90 ° ± 10 ° to the measuring patch plane of the measurement object is aligned.