DD279309C2 - APPARATUS FOR CONTACTLESS MEASUREMENT OF THE TEMPERATURE OF INTERNAL WALKS - Google Patents

Description

According to the invention the object is achieved in that concentrically to the longitudinal axis of a Meßohiiktes a measuring tube made of transparent, optically homogeneous material in the region of the front side of the measurement object in this projecting movable or fixed interchangeable, wherein the end face of the protruding into the measurement object measuring tube an outward or has inward conical or lenticular shape, which has a plane ground annular surface perpendicular to the longitudinal axis of the measuring object protruding from the object to be measured, at which one or more deflection prisms or mirrors adjoin one another in the optical axis, following lenses lying in deflected optical axis, Apertures and radiation receiver are arranged.

According to a further feature, the deflecting prisms or mirrors are provided with apertures having flat side surfaces. Preferably, the measuring tube according to the invention consists of quartz glass. In an advantageous embodiment of the invention, at least one of the panels is movable.

Above all, the advantage of the invention is that with the device according to the invention, the surface temperature in the optical spectral region of a defined annular region on the inner wall in the high-temperature region can be measured exactly and unadulterated.

Ausführungsbeispiul

The invention will be explained in more detail using an exemplary embodiment.

Fig. 1: Shows the basic structure of the device according to the invention

 Fig. 2-5: Show design forms of the front side of the measuring tube.

In an advantageous embodiment for measuring the temperature profiles or for controlling the temperature regime in the protective tube or heater of fiber optic Ziehanlagen the measuring tube 2, consisting of quartz glass, from below concentrically into the test object 1, in this case in the protective tube or the heater introduced. In this case, the upper end face 3 of the measuring tube 2 preferably has an inwardly conical or lenticular contour corresponding to Fig. 2 or 4, because the received temperature radiation, which reaches the receiver 12, such as photoreceptor, this case no influence by position or shape of the is subject to spoiled goods. Depending on the task, the measuring tube 2 can be slidably or permanently installed in the axial direction. A lenticular contour acc. 4 and 5 is advantageously carried out so that the radiation of a nearly circular ring portion of the measuring object 1 is forwarded in the measuring tube 2 parallel to the longitudinal axis. The projecting from the Rozipienten annular surface 4 of the measuring tube 2 is ground flat, it is followed by a 90 ° -Umlenkprisma 6, which has a breakthrough with ground flat, polished side surfaces for the implementation of the fiber optic fiber 5 and the blunt preform.

In the so deflected by 90 ° optical axis 7, an objective 8 is arranged so that it sharp images the exit plane of the deflecting prism 6 on the field of view diaphragm 10. This is designed as a solid contour aperture that leaves a circular ring corresponding to the ring surface 4 free. It is connected to a glass body 11 which conducts the radiation to a receiver 12.

In the focal plane of the lens 8 is a pinhole 9 with gradually variable diameter. By changing the diaphragm diameter, the angular range can be varied by the radiation guided parallel in the quartz tube, within which the radiation falls on the receiver. By means of the refraction on the front side 3 of the measuring tube 2, the width of the ring zone used for signal extraction can thus be varied within limits.

In another embodiment, in which the upper end face 3 of the measuring tube 2 is ground conically (Fig. 2 or 3), in position-fixed measuring tube 2, the position of the measuring location on the thermowell or Heizeroberfläche be varied in that the annular üesichtsfeldblende 10th is movable, such that the diameter of the diaphragm ring is varied.

Claims (4)

1. A device for non-contact measurement of the temperature of inner walls of tubular objects to be measured by known deflection prisms, optical imaging and receiver systems, characterized in that concentric with the longitudinal axis of the measurement object (1) a measuring tube (2) made of transparent, optically homogeneous Material in the region of the front side of the object to be measured (1) in this protruding movable or fixed interchangeable, wherein the end face (3) in the measuring object (1) projecting measuring tube (2) has an outwardly or after inneliegende cone or lens shape in that the face (4) of the measuring tube (2) protruding from the object of measurement (1) has a flat ground ring surface (4) perpendicular to the longitudinal axis, to which one or more deflection prisms or mirrors (6) adjoin in the optical axis deflected optical axis (7) lying below lenses (8), aperture (9; 10) and one or more Empfä are arranged (12). 2. Apparatus for non-contact measurement of the temperature of inner walls of tubular DUTs according to claim 1, characterized in that the measuring tube (2) consists of quartz glass. 3. A device for non-contact measurement of the temperature of inner walls of tubular DUTs according to claim 1-2, characterized in that the deflection prisms or mirrors (6) have openings with flat side surfaces. 4. A device for non-contact measurement of the temperature of inner walls of tubular DUTs according to claim 1-3, characterized in that at least one of the apertures (9; 10) is movable. For this 2 pages drawings Field of application of the invention The invention relates to a device for non-contact measurement of the temperature of inner walls, in particular tubular DUTs, for example heating or Schulzrohre, as they are used in the production of Lichlwellenleitern or as atomizers in atomic absorption spectroscopy. Characteristic of the known state of the art In heating or protective tubes in fiber optic drawing systems, a radially symmetric temperature distribution of the inner wall is desired, which, however, may have disturbances within certain limits. In contrast, the temperature field in the axial direction has significant gradients. Of interest, because relevant to the technological effect, is the knowledge of an effective temperature value of a ring area within the hsißesten zone. In this case, a channel along dbi cylinder axis must remain free to carry out the preform or the withdrawn fiber. Until now, fiber optic technology relinquished knowledge of the internal wall temperature and controlled the heating power with the help of a temperature signal obtained in the outer heater area, which required constant corrections based on the control of other technological parameters. An additional continuous measuring bore in the surface of the Hoiz- or protective tubes, as it is known from the atomizer in the ASS ago, led to disturbances within the protective gas regime, to disturbances within the radial symmetry of the temperature field (depending on the size of the bore), the resulting obtained temperature signal would be subject to further error influences through the thermowell and heater walls. A method according to DE-OS 2338585 (lead fiber optic bundles from the inside in the vicinity of the measuring point) is not possible because of the high temperatures of the heater, which led to the destruction of the fibers. For the same reason and because of the disturbance of the gas flow conditions, a method according to DE-OS 3118080 is not feasible. Since graphite in the high temperature range already represents a relatively good heat conductor, there is also no heat conductor analogous to DE-OS 3414694, which provides a solution to the problem. Object of the invention The aim of you invention is to provide a cost-effective device with which in particular the effective surface temperature of inner walls of tubular objects to be measured in the high temperature range without additional breakthrough in the outer surface of the test object and additional technological parameters can be measured. Explanation of the essence of the invention The object of the invention is to develop a device with which a surface temperature in the optical spectral range of a defined annular region of the inner wall in the high temperature range can be measured accurately without causing disturbances within the protective gas regime and the radial symmetry of the temperature field and to error influences on the temperature signal comes.