Arrangement in connection with measuring window of refractometer, and refractometer

• US 10,113,960 B2
• Filed: 06/27/2016
• Issued: 10/30/2018
• Est. Priority Date: 06/29/2015
• Status: Active Grant

• Current Assignee: Vaisala Oyj
• Original Assignee: Janesko Oy
• Inventors: Kamrat, Esko
• Primary Examiner(s): Decenzo, Shawn
• Application Number:
  US15/193,669
• Publication Number:
  US 20160377538A1
• Time in Patent Office: 855 Days
• CPC Class Codes: G01N 2021/434 Dipping block in contact with sample, e.g. prism
• CPC Class Codes: G01N 21/43 by measuring critical angle

Abstract

An exemplary arrangement includes a prism-shaped measuring window, which has a measuring surface adapted to contact a substance being measured. A first surface is adapted to direct light originating from a light source to the measuring surface through the measuring window. A second surface is adapted to direct totally reflected light from an interface between the measuring surface in contact with the substance being measured and a substance being measured outside of the measuring window. A first lens arrangement is adapted to focus the light from the light source on the first surface. A second lens arrangement is adapted to focus the totally reflected light passing through the second surface to a device used for analysis. A lens in each of the first and second lens arrangements closest to the measuring window is integrated into the measuring window and establishes optical refractive power in the first and second surfaces.

Claims

1. An arrangement in connection with a measuring window of a refractometer, the arrangement comprising:

a prism-shaped measuring window, which has a measuring surface adapted to contact a substance being measured;

a first surface through which light originating from a light source is adapted to be directed to the measuring surface through the prism-shaped measuring window;

a second surface, through which totally reflected light from an interface between the measuring surface in contact with the substance being measured and the substance being measured, is adapted to be directed outside of the measuring window for analysis; and

a first surface normal of the first surface and a second surface normal of the second surface having an intersection point at the interface between the measuring surface in contact with the substance being measured and the substance being measured, the intersection point being adapted to a center point of the measuring surface;

wherein a totally reflected part of light directed to the measuring surface along the first surface normal is adapted to be directed outside of the measuring window along the second surface normal;

a first lens arrangement and a second lens arrangement, each of the first lens arrangement and the second lens arrangement including at least two lenses,

wherein the first lens arrangement is adapted to focus the light originating from the light source on the first surface, and the second lens arrangement is adapted to focus the totally reflected light passing through the second surface to a device used for analysis,

wherein a lens in each of the first and second lens arrangements that is closest in relation to the measuring window is integrated into the measuring window, and surfaces of the lens in each of the first and second lens arrangements is adapted to form the first and second surfaces, respectively, which have optical refractive power, and

wherein the lens in each of the first and second lens arrangements that is closest in relation to the measuring window is of a same material as a material of the measuring window and is adapted to form a seamless structure with the measuring window.

2. The arrangement as claimed in claim 1, wherein the first and second surfaces are spherical or aspherical surfaces.

3. A refractometer comprising:

a measuring window; and

an arrangement as claimed in claim 1 in connection with the measuring window.

4. A refractometer comprising:

a measuring window; and

an arrangement as claimed in claim 2 in connection with the measuring window.

5. An arrangement in connection with a measuring window of a refractometer, the arrangement comprising:

a triangular prism-shaped measuring window, which has a measuring surface adapted to contact a substance being measured;

a first surface through which light originating from a light source is adapted to be directed to the measuring surface through the triangular prism-shaped measuring window;

a second surface, through which totally reflected light from an interface between the measuring surface in contact with the substance being measured and the substance being measured, is adapted to be directed outside of the measuring window for analysis; and

a first lens arrangement and a second lens arrangement,

wherein a first lens of the first lens arrangement is adapted to focus the light originating from the light source on the first surface, and a second lens of the second lens arrangement is adapted to focus the totally reflected light passing through the second surface to a device used for analysis,

wherein a third lens in the first lens arrangement and a fourth lens in the second lens arrangement that are closest in relation to the measuring window are each integrated into the measuring window, and surfaces of the third lens and the fourth lens are adapted to form the first and second surfaces, respectively, which have optical refractive power, and

wherein the first lens and the third lens are arranged to have a common center axis;

wherein the second lens and the fourth lens are arranged to have a common center axis;

wherein the third lens and the fourth lens are of a same material as a material of the measuring window and is adapted to form a seamless structure with the measuring window;

wherein the second surface and the second lens arrangement including the second surface form an optical system having a focal length at a distance of which a light-sensitive surface of a device used in the analysis is set.