JPH0797075B2 - Particle size distribution measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a particle size distribution measuring apparatus to which the Stokes sedimentation method is applied.

<Prior Art> When the particle size distribution is measured by the sedimentation method, the viscosity coefficient and the density at the temperature of the medium liquid used for the measurement in the process of data processing are required. In the past, the measurer measured the temperature of the liquid medium at the time of sample preparation, investigated the viscosity coefficient and density at that time from the constant table, and input it to the data processing device.

<Problems to be solved by the invention> However, in this conventional technique, the measurer measures the temperature each time the measurement is performed, and the viscosity coefficient and the density at that temperature are searched from the constant table for the medium, It is necessary for the measurer to input the data into the data processing device, which is troublesome and error-prone.

It is an object of the present invention to provide a particle size distribution measuring device that eliminates such drawbacks.

<Means for Solving Problems> The present invention is a particle size distribution measuring apparatus using a sedimentation method, and stores in advance viscosity coefficients and densities corresponding to respective temperatures for several kinds of medium liquids used. And a computing unit for automatically searching for the viscosity coefficient or density of the corresponding medium or both the viscosity coefficient and the density based on the type of the medium and the temperature of the sample suspension to be input. I am trying.

<Action> The type of the medium liquid is manually input, and the temperature information of the sample suspension is automatically or manually input from the measuring device, so that the viscosity coefficient corresponding to the type and temperature of the medium liquid, The density is automatically searched and used for the calculation processing of the particle size necessary for measuring the particle size distribution.

<Embodiment> The drawings are block diagrams showing an embodiment of the present invention.

For the sample suspension 2, put the sample powder and the medium liquid in another beaker 13,
It is prepared by stirring with a magnetic stirrer 17, and this is sent to the sample cell 1 by the circulation pump 11. The change in the concentration of the sample suspension 2 due to the sedimentation of particles during the measurement is detected as a change in the amount of X-ray transmission by the combination of the X-ray tube 3 and the scintillation counter 4, and is processed by the absorbance measuring circuit 5 to be processed by the XY recorder. Record on the Y-axis of 6. On the other hand, a temperature measuring element 14 for measuring the temperature of the suspension 2 is installed inside the beaker 13, and the temperature signal obtained by the temperature measuring element 14 is used as a temperature measuring circuit 15.
The signal is input to the control unit 30 via the A / D converter 16. The control unit 30 is mainly composed of a microcomputer, and executes the various calculations and programs, and controls each peripheral device, the CPU 18, the ROM 19 in which the operation procedure of the device and other calculation formula programs are written, various data and calculation results, etc. RAM20 for storing, i / o for connection with external equipment
It has ports 8 and so on. Reference numeral 21 denotes an operation switch, which allows the type and temperature of the liquid medium to be manually input or a measurement start command to be input.

In the present invention, the ROM 19 stores in advance the relationship between the viscosity coefficient or the density for each temperature, or both the viscosity coefficient and the density for some of the liquid media. And as a preparation prior to the start of measurement, it can be considered that the temperature of the medium liquid is equal to the temperature of the sample suspension, so the type of medium and the temperature of the sample suspension are input to the CPU 18, and the type And the viscosity of the liquid medium corresponding to the temperature and the temperature, or both the viscosity coefficient and the density are automatically retrieved, and the condition for the particle size calculation is set. The type of the medium is input with the operation switch 21, and the temperature of the medium is measured by the temperature measuring element 14, the temperature measuring circuit 15, the A / D converter 16
However, the temperature may be manually input by the operator from the operation switch 21 by measuring the temperature of the medium liquid.

When a measurement start command is input with the operation switch 21 when the measurement conditions are determined, the i / o port 8
Sends a signal to the driver 12 to stop the circulation pump 11 that has been working until then, and the particles in the suspension 2 in the sample cell 1 start to settle. As described above, the change in the concentration with the passage of time passes through the X-ray tube 3, the scintillation counter 4, and the absorbance measuring circuit 5, and the XY recorder 6
Is recorded on the Y-axis of. On the other hand, the particle diameter is calculated by the CPU 18 based on the viscosity coefficient and density automatically searched for, and the signal is C
It is sent from PU18 to driver 7 via i / o port 8,
The X axis of the XY recorder 6 is driven. Thereby, the particle diameter is displayed on the X axis and the concentration corresponding to the particle diameter, that is, the ratio of particles having the particle diameter is displayed on the Y axis.

In order to shorten the measurement time, the motor 10 is driven from the control unit 30 via the driver 9 to lower the cell 1 at a predetermined constant speed so that the measurement position by the X-ray tube 3 is set to the cell 1. Move it up. As a result, even small particles with slow sedimentation can be measured in a short time.

When determining the measurement conditions, the sample cell 1 and beaker
13, and by keeping the temperature of the suspension chamber constant by adjusting the temperature of the measuring chamber containing the pipe, stop measuring each time, and measure the viscosity coefficient and density at a certain temperature. The liquid medium may be stored.

<Effect> The present invention is configured as described above, and stores the viscosity coefficient and density corresponding to each temperature for several kinds of liquid media in advance in the storage unit, and inputs the type of liquid media and sample suspension. Since the viscosity coefficient and density of the corresponding liquid medium are automatically searched from the temperature of the liquid, the operator does not need to search the viscosity coefficient and density from the constant table for the liquid medium until the start of measurement. The time required for can be greatly reduced.
Further, the search operation by the measurer before the start of measurement is busy, and a search error or an input error is likely to occur, but the present invention can prevent such a search error or an input error. In addition, if the temperature of the sample suspension is automatically input using a temperature measuring element, it is not necessary for the measurer to measure the temperature and manually input it, which enables quick and error-free measurement. Become. In addition, it is possible to develop a system that supports online measurement by adding a sampler.

[Brief description of drawings]

 The drawings are block diagrams showing embodiments of the present invention. 1 ... Sample cell, 2 ... Sample suspension 14 ... Temperature detector, 18 ... CPU 19 ... ROM, 21 ... Operation switch

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shohei Ishida 1 Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto Prefecture Kyoto Sanjo Factory Sanjo Factory (72) Inventor Jun Sakai 1 Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto-shi, Kyoto Prefecture Shimadzu Sanjo Factory

Claims (3)

[Claims] 1. A particle size distribution measuring apparatus using a sedimentation method, comprising: a storage unit in which viscosity coefficients and densities corresponding to respective temperatures of several kinds of medium liquids are stored in advance; A particle size distribution measuring device, comprising: an arithmetic unit for automatically searching for the viscosity coefficient or density of a corresponding liquid medium or both of the viscosity coefficient and density based on the type and the temperature of the sample suspension. 2. The particle size distribution measuring apparatus according to claim 1, wherein the temperature of the sample suspension is automatically input to the arithmetic unit by using a temperature sensing element immersed in the suspension as a detection element. 3. The particle size distribution measuring device according to claim 1, wherein the temperature of the sample suspension is kept constant.