JPH0562828U - Optical measuring device - Google Patents

Abstract

(57) [Summary] [Purpose] The measurement window is not contaminated by dust,
Moreover, an optical measuring device configured so as not to interfere with the optical measurement is provided. [Arrangement] An optical measuring device, wherein light is projected onto a measuring object (A) through a measuring window (2) or light from the measuring object (A) is received for measurement, and the measuring window (2) is used.
A perforated plate (4) is arranged on the front surface of the via a space (8),
It is characterized in that a purge gas as a pressure gas is introduced from the periphery of the void into the void and the purge gas can be discharged to the outside through the porous plate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical measuring device such as a radiation thermometer and an infrared moisture meter which are used in a relatively dusty environment.

[0002]

[Prior Art]

 Generally, in an environment with a lot of dust, for example, in an alloying furnace for hot-dip galvanized steel sheets, it is necessary to prevent the measurement window from becoming dirty in order to ensure measurement accuracy when performing optical measurements. .. Therefore, measures such as mounting a transparent plate on the window frame and constantly spraying purge gas on it are taken.For example, a light source is provided inside the measuring device, and light is emitted from the light source to the measurement target through the measurement window. If the measurement window needs to be made quite large as in an optical measurement device that irradiates and receives the reflected light again through the measurement window to the inner sensor to perform measurement, There is a problem of measurement uncertainty due to insufficient purging and inconsistent removal of dirt.

[0003]

[Problems to be solved by the device]

 Therefore, in an optical measurement method that has a light source inside, irradiates this light to a measurement target, and measures its optical properties, such as reflectance, absorptance, and roughness, with the reflected light from the target. However, it is necessary to devise to prevent stains.

[0004]

[The purpose of the device]

 The present invention has been made based on the above circumstances, and an object thereof is to provide an optical measuring device configured so that the measurement window is not contaminated by dust and does not interfere with optical measurement. ..

[0005]

[Means for Solving the Problems]

 Therefore, in the optical measuring device of the present invention, as is apparent from the illustrated embodiment, light is projected onto the measuring object (A) through the measuring window (2) or the measuring object (A) emits light. In an optical measuring device adapted to receive and measure light, a perforated plate (4) is disposed in front of the measurement window (2) through a void (8), and the void is surrounded by the void. It is characterized in that a purge gas as a pressure gas is introduced into the inside and the purge gas can be discharged to the outside through the porous plate.

[0006]

[Action]

 Therefore, dust that tries to enter the inside of the device from the outside through the hole of the perforated plate (4) is pushed out from the measurement window (2) by the pressure gas discharged from the hole of the perforated plate (4). Since it is returned, it does not adhere to the portion of the measurement window (2), so that an accurate measurement result can be secured for a long period of time.

[0007]

【Example】

 Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings. A measurement window 2 is opened on the front surface of the apparatus main body 1 in this embodiment. A transparent plate 3 made of quartz glass is mounted on the inner circumference of the inner frame 2A formed along the inner circumference of the measurement window 2, and the outer frame 2B formed along the outer circumference of the front part of the transparent plate 3 is attached. A perforated plate 4 called a punching metal is attached to the front end face of the. Inside the inner frame 2A, a storage passage 6 for introducing and storing purge gas through a purge pipe 5 arranged in the apparatus main body 1 is continuously formed in the circumferential direction, and the storage frame 6 of the outer frame 2B is formed. A straightening passage 7 is continuously formed in the inner circumference in the circumferential direction. Gas nozzles 6A are formed at a plurality of positions along the circumferential direction of the partition walls of the storage passage 6 and the rectifying passage 7, and the inner circumference of the rectifying passage 7 that forms the periphery of the gap 8 between the transparent plate 3 and the perforated plate 4 is formed. Is divided by a porous straightening plate 7A so that a clean pressure gas, for example, a purge gas such as air or nitrogen gas can be introduced uniformly from the straightening plate 7A into the space 8. ing. The current plate 7A can be formed of a sintered metal plate body. Further, a light source 9 is arranged inside the apparatus main body 1 so as to face the measurement window 2, and a sensor 10 composed of a light receiving element is arranged on one side thereof. The light emitted from the light source 9 through the measurement window 2 is reflected by the surface of the measuring object A and measured by the sensor 10 inside the measuring device. In this embodiment, optical paths 11 and 12 for guiding the reflected light to the sensor 10 are formed so as to penetrate the inner frame 2A and the outer frame 2B, respectively.

The pore diameter in the porous plate 4 and its distribution condition should be selected appropriately, and the discharge pressure of the purge gas discharged from the holes of the porous plate 4 should be taken into consideration.

In such a configuration, the light emitted from the light source 9 to the measurement target A through the transparent plate 3 and the porous plate 4 is received by the sensor 10, and the reflectance, the water absorption rate, the roughness, etc. Information can be obtained. Then, in the process of such measurement, since the purge gas as the pressure gas is discharged from the holes of the porous plate, the dust dispersed and floating in the external atmosphere does not approach the measurement window 2 and is exposed to the outside. It is pushed away, so the window does not get dirty over a long period of time, ensuring stable and accurate measurements. The measurement window having a porous plate on the front surface may be a measurement window dedicated to light projection, a measurement window dedicated to light reception, or a measurement window for both light projection and light reception. ..

[0010]

[Effect of the device]

 As described in detail above, the present invention provides a porous plate with a gap in front of a window in an optical measuring device, and introduces a pressure gas as a purge gas into the void inside the porous plate. However, since it is configured such that it can be discharged to the outside through the perforated plate, it is possible to prevent dust from adhering to the outside of the window and to prevent the optical measurement from being disturbed. That is, the dust that is about to enter the inside of the device from the outside through the holes of the perforated plate is pushed back to the outside from the window by the pressure gas discharged from the holes of the perforated plate, and the dust does not enter the window. It does not adhere, thus ensuring accurate measurement results over a long period of time.

[Brief description of drawings]

FIG. 1 is an overall schematic cross-sectional plane showing an embodiment of the present invention.

FIG. 2 is likewise an enlarged front view of a main part showing a specification mode.

FIG. 3 is likewise an enlarged cross-sectional plan view of a main part.

[Explanation of symbols]

1 Device Main Body 2 Measurement Window, 2A Inner Frame, 2B Outer Frame 3 Transparent Plate 4 Perforated Plate 5 Purge Pipe 6 Storage Passage, 6A Nozzle 7 Rectifying Passage, 7A Rectifying Plate 8 Gap 9 Light Source 10 Sensor 11, 12 Optical Path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiromichi Omiya 32-8 Kumano-cho, Itabashi-ku, Tokyo Chino Co., Ltd. (72) Yoshimi Fukutaka 1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama Prefecture ) Kawashima Steel Works Mizushima Steel Works

Claims (1)

[Scope of utility model registration request] 1. An optical measuring device for projecting light to a measuring object through a window or receiving light from the measuring object for measurement, wherein a porous plate is arranged on the front surface of the window through a gap. The optical measuring device is characterized in that a purge gas as a pressure gas is introduced from the periphery of the void into the void and the purge gas can be discharged to the outside through the porous plate.