JPS62100640A - Specific surface area measuring instrument - Google Patents

Abstract

PURPOSE:To enable the occurrence of a misdiscrimination or a misoperation to be prevented by a reading corresponding weight data in a memory from the result of the read of a cell number when an adsorbed quantity is measured and computing a specific surface area by dividing the value of the whole surface area of a specimen obtained from the measured value of the adsorbed quantity by the weight of the specimen. CONSTITUTION:A specimen container (a) is mounted to a measuring unit (b) and an adsorption gas is introduced into the container (a). The quantity of the gas adsorbed by a specimen is measured by adsorbed quantity measuring means (c) and the measured quantity of the adsorbed gas is converted into the surface area of the specimen by surface area computing means (d). When the container (a) is mounted to the measuring unit (b), a reader (e) reads an identification symbol M marked on the container (a). A memory 5 associatively stores the identification data of a plurality of the specimen containers inputted from outside and the weight data of the specimen in the containers. Specific surface area computing means (g) computes the specific surface area of the specimen from the surface area data of the specimen in the container (a) obtained by the means (d) and the specimen weight data in the memory 5 corresponding to the result of the read of the symbol M marked on the container (a).

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to an apparatus for measuring the specific surface area of powder or granular materials.

<Prior art> When measuring the specific surface area of powder or granular materials, conventionally, the sample to be measured is sealed in a sample container and the amount of gas adsorbed on the sample is measured using a flow method or a volumetric method. Measure the total surface area of the sample. Then, the weight of the sample is separately measured, and the specific surface area is calculated from the measured value.

When there are a large number of samples to be measured, the sample container is usually marked with an identification symbol such as a number, and the measured values of the weight and total surface area of the sample are written on a sheet of paper in correspondence with the identification symbol. A method of converting to specific surface area is adopted. Alternatively, in conventional, more automated devices, data is not written in the ξJE, but when measuring the amount of adsorption, the measurer has had to read the identification symbol attached to the sample container and input it using a keyboard, etc. .

<Problems to be Solved by the Invention> In all conventional devices, in order to match the total surface area data with the weight data, the measurer reads the identification symbol of the sample container when measuring the adsorption amount (total surface area). It is necessary to perform operations such as recording or inputting, and there is a risk that reading errors, operational errors, etc. will occur. In addition, with conventional devices, only the total surface area (m) of the sample in the sample container is displayed when measuring the adsorption amount, so the measurer can later convert it to the specific surface area (m/g) using the sample weight. I needed to.

The purpose of the present invention is to directly calculate and display the specific surface area of a sample without the need for the measurement person to read an identification symbol or perform any operations based on the results when measuring the specific surface area. The object of the present invention is to provide a specific surface area measuring device that can improve the efficiency of specific surface area measuring work and cope with LA.

<Means for Solving the Problems> The configuration of the present invention will be explained based on the basic conceptual diagram shown in FIG.

A sample container a containing a sample is attached to the measurement unit, an adsorbed gas is introduced into the sample container, and the adsorption amount measuring means C measures the amount of gas adsorbed by the sample in the sample container a. The measured amount of adsorption is converted into the surface area of the sample by the surface area calculating means d.

A reading device e is disposed near the measuring section, and this reading device e can read the identification mark M attached to the sample container a when the sample container a is attached to the measuring section.

The memory 5 can store identification data of a plurality of sample containers input from the outside and weight data of the sample placed in each sample container in association with each other. The specific surface area calculation means g uses the surface area data of the sample in the sample container a obtained by the surface area calculation means d and the sample weight data in the memory 5 corresponding to the reading result of the identification mark M attached to the sample container a. Calculate the specific surface area of the sample.

<Operation> By attaching the sample container a to the measurement unit, the identification symbol M attached to the sample container a is automatically read, and the corresponding one is selected from the data group stored in the memory f. The IT data of the material to be used is accessed. Then, the specific surface area of the sample is calculated from the weight data and the total surface area measurement data of the sample in the sample container a by the surface area calculating means d. The specific surface area of the sample can be displayed or recorded immediately without reading the identification symbol M or performing any operations based on the reading result.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a configuration diagram of an embodiment of the present invention. This example shows an example in which the present invention is applied to an adsorption amount measuring device using a flow method. To measure the amount of adsorption by the flow method, for example, a mixed gas made by mixing N2 as an adsorbed gas and He as a non-adsorbed gas at a ratio of 3=7 is used, and the N211 degree of the mixed gas before and after being adsorbed to the sample is used. From the difference, N depending on the sample
2 Physics “You can know the amount of adsorption.

The mixed gas is introduced into the piping of the device from the gas inlet, and the on-off valve 2. Pressure regulating valve 3. It passes through the flow rate control valve 4, during which the flow rate is kept constant. A constant flow rate of the mixed gas is guided into a cold tramp 5 using liquid nitrogen as a refrigerant, where impurities in the gas, especially water vapor, which has an adverse effect on the next stage thermal conductivity detector (hereinafter referred to as TCD) 6, are introduced. etc. are removed.

The cleaned mixed gas passes through the primary side of the TCD 6 and reaches the measuring section 7. Note that a septum 8 is provided in the middle of the pipe for injecting a reference gas for calibration into the pipe for surface area conversion. Further, the TCD 6 is maintained at a constant temperature by a temperature control circuit 9.

The measurement unit 7 includes a sample cell 10 containing a sample to be measured.
is attached, and its sample cell 10 can be immersed in liquid nitrogen. By cooling the sample cell 10 with liquid nitrogen, N2 in the mixed gas is physically adsorbed onto the sample surface.

Note that by removing the liquid nitrogen after reaching adsorption equilibrium, the sample is warmed to room temperature, which causes the adsorbed N2 to be desorbed.

The mixed gas that has passed through the sample cell 10 reaches the selector valve 12 via the sample scattering prevention filter 11 . This selector valve 12 allows selection of either the short path 13 or the long path 14 to be used. Generally, a short path 13 is used, and a long path 14 is used when the sample surface area is large. The mixed gas that has passed through either of these channels is guided to the secondary side of the TCD 6.

-While a constant mixture of gases always flows on the next side,
On this secondary side, the mixing ratio of gases flowing during adsorption/desorption by the sample changes. - Changes in the gas mixture flowing between the upstream side and the secondary side are detected by the TCD 6.

The mixed gas that has passed through the secondary side of the TCD 6 passes through a flow meter 15 and reaches a degassing section 16 . In this degassing section 16, the sample cell 10' is heated by the mantle heater 17 and a mixed gas is caused to flow therein, thereby degassing the sample as a pre-measurement treatment. The mixed gas that has passed through the salt gas section 16 is discharged to the outside of the apparatus from the gas outlet 19 via the backflow prevention section 18.

The output of the TCD 6 is increased by the amplifier 20,
After being divided by the division circuit 21, the CPU 23. ROM24. It is incorporated into a microcomputer equipped with RAM25 and the like.

A known formula for calculating the total surface area of the sample from the integral value is written in the ROM 24, and furthermore, a formula for calculating the specific surface area for dividing the obtained total surface area by the weight of the sample is written, as will be described later. There is.

Now, a first cell number identification sensor 26 is disposed adjacent to the measurement section 7 described above. The output of the first cell number identification sensor 26 is input to the microcomputer via a cell number reading circuit 27 and an input/output port 28. The first cell number identification sensor 26 can read the cell number M of the sample cell 10 attached to the measuring section 7 in cooperation with the cell number reading circuit 27, as will be described later. That is, as shown in FIG. 3, which is an external perspective view of the vicinity of the sample cell 10 attached to the measurement section 7, the holder section 10a of the sample cell 10 includes:
A cell number writing section 10b is attached, and a cell number M is written in this cell number writing section 10b, as shown in an enlarged view in FIG. When the sample cell 10 is attached to the measuring section 7, the cell number writing section 10b is configured to be located at a position corresponding to the arrangement position of the first cell number identification sensor 26.

For example, the cell number M adopts a 7-segment system,
Necessary segments are passed through to display a unique number in each cell. The first cell number identification sensor 26 includes a light emitting section and a light receiving element disposed at a position corresponding to each segment, and supplies the output of each light receiving element to the cell number reading circuit 27. The cell number is read and the data is entered into the microcomputer.

The cell number reading circuit 27 is also supplied with the output of a second cell number identification sensor 29 similar to the first cell number classification sensor 26 . This second cell number identification sensor 29 is disposed in an electronic balance 30 that can transfer weighing data to a microcomputer. The attached cell number M is read and the data is input into the microcomputer along with the weight data. Then, for each sample cell, the internal sample weight data corresponding to the cell number is
Stored in M25.

FIG. 5 shows an external perspective view of the electronic balance 30 with the second cell number identification sensor 29 attached, and FIG. 6 shows a side view of the sample cell 10 placed on the JTu 30aJ2. A positioning block 31 is fixed on the pan 30a of the electronic balance 30, and the positioning block 31 positions the sample cell 10 during weight measurement.As a result, the cell number writing section 10b reads the second cell number. It is configured to be located at the position of the identification sensor 29.

When determining the specific surface area of multiple samples using the above embodiments of the present invention, after each sample is sealed in a sample cell,
First, the weight is measured using the electronic balance 30. Thereby, each sample weight data is stored in the RAM 25 in correspondence with the cell number of each sample cell.

Next, when an arbitrary sample cell 10 is attached to the measuring section 7, its cell number M is read. When the measurement of the adsorption amount of the sample in the sample cell 10 is completed, the total surface area of the sample is calculated based on the measurement results, and the cell number M
Based on the read result, the corresponding weight data is read out from the weight data group stored in the RAM 25, and the specific surface area of the sample is calculated by dividing the total surface area by the sample weight using the specific surface area calculation formula. is calculated and, for example, display 3
2.

In addition, the cell number may be represented by another method, for example, a barcode method, instead of the above embodiment, and in this case,
The cell number identification sensors 26 and 29 may be constructed of barcode leagues. Further, in the above embodiment, an example was shown in which the second cell number identification sensor 29 was disposed on the electronic balance 30, but the position where it is disposed is not particularly limited. It is also possible to later place a sample cell at that location and read the cell number. Furthermore, the second cell number identification sensor 29 is not necessarily required; for example, the sample weight may be measured using a separate balance, and the data may be input into the microcomputer together with the cell number. Furthermore, the method for measuring the amount of adsorption is not limited to the above-mentioned flow method, and it goes without saying that a capacitance method may be used.

Effect> As explained above, according to the present invention, a cell number is attached to each sample cell, and a means is provided for reading the cell number when the sample cell is attached to the measurement section, and the amount of sample M is A memory is provided to store the weight data in correspondence with the cell number, and when measuring the adsorption amount, the corresponding weight data in the memory is read out based on the cell number reading result, and the total surface area of the sample determined from the adsorption amount measurement value is read out. Since the specific surface area is calculated by dividing the value by the weight of the sample, there is no need for the measurer to identify the cell number or perform operations based on the results when measuring the amount of adsorption. As a result, not only is the measurement work simplified, but there is no risk of identification or operation errors. In addition, since the specific surface area is immediately displayed or recorded, the measurer does not have to calculate the specific surface area from the total surface area and weight as in the past, and the efficiency of the measurement work is improved.

Furthermore, if the cell number is read by a similar reading means during weight measurement and the data is automatically stored in the memory along with the weight data, the effect will be even greater and it will also be possible to cope with LA. I can do it.

[Brief explanation of drawings]

FIG. 1 is a basic conceptual diagram showing the configuration of the present invention, FIG. 2 is a configuration diagram of an embodiment of the present invention, FIG. 3 is an external perspective view of the vicinity of the sample cell IO installed in the measurement section 7, and FIG. 4 is an enlarged view of the cell number writing section 10b, FIG. 5 is an external perspective view of the electronic balance 30 with the second cell number identification sensor 29 attached, and FIG. 6 is the pan 3 of the electronic balance 30.
FIG. 2 is a side view showing a state in which a sample cell 10 is placed on 0a. 6...TCD, 7...Measuring section, 10...Sample cell 10b...Cell number writing section 21...Integrator circuit, 23...CPU24...
・ROM, 25...RAM26...1st
Cell number identification sensor 27...Cell number reading circuit 29...Second cell number identification sensor 30...Electronic balance

Claims (2)

[Claims] (1) In an apparatus in which a sample container containing a sample is attached to a measuring section, an adsorbed gas is introduced into the measuring section, and the surface area of the sample can be determined from the amount of the adsorbed gas adsorbed by the sample in the container. A reading device is installed near the sample container and reads the identification symbol attached to the sample container when the sample container is attached, and the identification data of multiple sample containers and the sample weight data in each sample container are input from the outside. a memory that stores data in association with the above, surface area measurement data of a sample in a sample container attached to the measurement section, and a sample weight in the memory corresponding to the reading result of an identification mark attached to the sample container; 1. A specific surface area measuring device, comprising a specific surface area calculation means for calculating the specific surface area of the sample from the data. (2) A patent claim characterized in that the input of the identification data to the memory is the input of the result of reading the identification symbol of the sample container by a reading device provided at an arbitrary location separately from the reading device. The specific surface area measuring device according to item 1.