JPH0473740B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for measuring light scattering of fine particles present in various liquids.

(Prior art and problems) Conventionally, a square optical cell with a square cross section as shown in Fig. 4 is used for scattering photometry, and the liquid to be measured is placed in the cell and the square optical cell is heated. A light source emits a constant beam of parallel light from the side perpendicular to the axis through a filter and slit, and the light scattered by the liquid to be measured is received by the light receiving part from the front of the rectangular optical cell. There are some things that can be observed with increased width. As shown in Figure 5, this rectangular optical cell allows for accurate measurements because it does not cause diffuse reflection of incident light, but since the four sides are made of optical glass and each side is bonded by vapor deposition, each
It is expensive at 5,000 yen, and conventional measuring devices require at least 10 of these square cells, which alone accounts for a considerable amount of price.

Therefore, the inventor of the present invention tried various ways to measure the scattered light intensity by using an ordinary cylindrical test tube (round cell) instead of the above-mentioned square optical cell. Similar to the above method, when a constant beam of parallel light is irradiated from the side of the test tube and observed from the front, the parallel light is diffusely reflected on the inner surface of the test tube as shown in Figure 6, and only the liquid to be measured is scattered. Light was something that could not be measured. In this test tube, even when the liquid is transparent, parallel light is diffusely reflected on the inner surface of the test tube, so there is a problem in that this diffusely reflected light affects the light receiving section.

(Means for Solving the Problems) The present invention uses a commercially available inexpensive test tube (round cell) to perform the same light reception measurement as a conventional square optical cell. As shown in Fig. 3, by irradiating a test tube with a constant incident angle of parallel light from a side position that is deviated by a certain angle α from a right angle to the axis of the test tube, the reflected light of the parallel light inside the test tube is is curved in the opposite direction by an angle equal to the incident angle from a right angle to the axis, and the portion through which the incident light ' and the reflected light ' do not pass is measured from the front.

[Example] As shown in FIG. 1, the present invention emits a constant luminous flux from a light source above the side of a test tube, which is a round cell, through a diaphragm and deviating by a constant angle α from perpendicular to the axis of the test tube. A method in which parallel light is irradiated, the part of the parallel light inside the test tube that does not cross the incident light ′ and reflected light ′ is received from the front by the light receiving part, and this is further amplified by the amplification part and observed. be.
That is, the principle of the method of the present invention is that, as shown in FIG. The reflected light ' is reflected downward at an angle twice the incident angle α of the incident light ', and when viewed from the front, a portion (a dot pattern portion) through which neither the incident light nor the reflected light passes is created.
In the present invention, light is received from the front center part' of this part by a light receiving section, and the diffusely reflected light by the fine particles in the liquid to be measured is measured.

If the angle α of the incident light is too large, less light will enter the test tube, and if it is too small, diffuse reflection will occur within the test tube, which will affect the light receiving section, so it is preferably about 45°. , is not particularly limited.

The method of the present invention is carried out in the form shown in FIG. 2, by way of example. In other words, the test tube is placed in pressure contact with the inner corner of the flat L-shaped cell holder, and placed on one of the right-angled outer surfaces (side surfaces) of the cell holder, pointing diagonally downward toward the center of the test tube. Provide a light source at a predetermined position on the other external surface (front) (the part where the incident light and reflected light do not cross)
If a light-receiving section is provided in the test tube for measurement, setting the test tube is reliable, easy, and convenient.

In addition, if the light source and light receiving part of the cell holder are made to be able to slide vertically and horizontally using appropriate means depending on the diameter of the test tube, it will be adaptable even if the diameter of the test tube changes. .

(Effects of the Invention) As described above, the present invention does not make the incident angle of the parallel light perpendicular to the axis of the test tube, but tilts it up and down at a certain angle α to deflect the reflected light on the inner surface of the test tube in a certain direction. By securing a part within the parallel light where the incident light and reflected light do not pass through, and using this part as the light receiving part, it is possible to obtain the same photometric performance as a conventional square cell even using a commercially available inexpensive test tube. effective. Therefore, a measuring device employing the method of the present invention is inexpensive and has high industrial applicability.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram schematically showing a measurement form according to the present invention, Fig. 2 is a perspective view schematically showing an example of a measuring device, and Fig. 3 shows the principle of the method of the present invention, and A is a plane. Fig. 4 is a schematic perspective view of the conventional device, Fig. 5 shows the principle of measurement using a conventional square cell, A is a plan view, B is a front view, and Fig. 6 is a front view.
The figures show the principle of using test tubes in the conventional method, with A being a plan view and B being a front view. 1...test tube, 2...parallel light, 3...reflected light,
5...Light source, 7...Light receiving section.

Claims (1)

[Claims] 1. Put the liquid to be measured in a cylindrical test tube, and irradiate it with a constant beam of parallel light from a side position with the incident angle of the light deviated by a certain angle from the right angle to the axis of the test tube,
A scattering photometry method in which a portion of the parallel light in a test tube that does not cross the reflected light is observed from the front.