JPS5960244A - Electronic sedimentation balance - Google Patents

Abstract

PURPOSE:To make it possible to perform realtime measurement of sedimentation rate and the like of sedimenting powder without waiting for the completion of sedimentation, by displaying the computed sedimentation rate and the like together with the elapsed time, based on the detected load value, which undergoes tare subtraction process in a processor. CONSTITUTION:A control part 5 in a processor including a CPU and the like converts the weight of powder sample from a load detecting part 1 into the weight in a medium liquid. This is based on the density of the powder sample in a pan 2 that is set by a keyboard 9; the density of the medium liquid in a suspended a sedimentation dish 4; and the like. Tare substration porcess is performed on the detected load value when the powder sample is dispersed in the medium liquid. Then the start of measuring is instructed. After the specified time, a sedimentation rate is computed from the detected load value by the processing of the control part 5. The elapsed time and the sedimentation rate are displayed on a display device 8. The proper elapse time thereafter is determined by the control part 5 based on the sedimentation rate. The sedimentation rate of the sedimenting powder is displayed together with the elapsed time in realtime at every predetermined elapse time. By the similar way, diameter of particles and the change in sedimentation rate are computed and displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sedimentation bottle for determining the particle size distribution of o'5) bodies.

As one method for measuring the particle size distribution of powder, a sedimentation balance method based on Stokes' law has been used for a long time. In conventional sedimentation balances, a sample uniformly stirred in a medium is deposited on the sedimentation plate 1, and the sedimentation curve according to the elapsed time and G after the start of sedimentation is recorded on a recording paper. For example, it was necessary to wait for the sample to complete sedimentation, calculate the sedimentation rate, etc. based on the sedimentation weight at the time of completion of sedimentation, and calculate the O'η degree distribution. In addition, changes in recording time due to differences in sedimentation speed of the sample to be measured are fixed at several stages depending on the feed speed of the recording paper, which has the disadvantage that it may be difficult to perform h'l Kn during subsequent analysis. have.

The present invention has been made in view of the above, and an object of the present invention is to provide an electronic sedimentation balance that can display elapsed time, sedimentation rate, etc. every moment during the sedimentation process without waiting for the completion of sedimentation.

The feature of the present invention is that the test 1 in air (the powder weight is converted into the weight in the medium and stored, and the sample powder is expanded into the medium)
At the same time as the measurement start signal is issued, the sedimentation rate is calculated by dividing the weight of the sediment in the sedimentation dish by the converted sample weight in the medium described in 1-1, and the measurement start signal is issued. ) departure 4L1
The elapsed time of & is displayed moment by moment (2)).Furthermore, by converting the elapsed time described above into a particle diameter using the Stokes equation, the deposition rate and deposition change rate for a given particle diameter can be calculated. etc. can be displayed.

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

The multi-layer detection unit 1 is provided with a weighing pan 2 and a sinking ti11.4 suspended from a lower hook 3 provided on the same line of load action as the weighing pan 2, and is used for load detection. Section I detects the load acting on these weighing pans 2 and sinking pans 4, digitally changes them every predetermined period of time, for example, every 0.2 seconds, and outputs them to the control section 5. The sedimentation ItlL 4 is submerged in a sedimentation container 6 filled with a medium, and a container 7 for holding sample 1 powder is placed on the weighing pan 2. In this state, the load detection unit It is set so that the output of 1 becomes 0. The control unit 5 is composed of a microphone I:]
Central processing unit (CI) which executes various 6ij calculations and controls each peripheral device, only-memory IJROM which stores processing programs, load detection 1
It is made up of i+4 random access memory RAMs, etc., each having an area for storing digital data from 1 and 1 area as various registers, and these are connected to each other by a line. The control unit 5 includes a display 8 that displays elapsed time, sedimentation rate, rate of change in sedimentation, particle i, etc. based on commands from the control unit 5, various operation keys such as the tare bow 1 key, and initial condition setting. A keyboard 1'9 equipped with a numeric keypad etc. is connected.

Next, the function of the embodiment of the present invention will be explained along with the method of use.

FIG. 2 (al, (1)l) is a flowchart of the embodiment of the present invention, without showing the processing block J.

First, prior to measurement, various constants, ie, the density ρf of Todoroki's material, the density ρS of the medium, the viscosity η of the medium, etc., are input from the keyboard 9 (STI). Next, when Mr. S fl labor body of arbitrary weight is put into the container 7 on the tray 2,
The moxibustion data from the load detection unit 1 becomes a value corresponding to the weight, and the control unit 5
Random access memory IJ RAM is loaded. Random access memory lJRAM & maximum n-1-
One data storage area is provided, and the latest data (G, oldest I, I, etc.) 5'-ta dn is discarded every time 10 data are taken in (ST2, 5T3). Random access memory RAM
Of the -1-events taken in, the latest i (if one column is 3 (fixed) data Q, then the Hei 1 phrase (direct WO) is calculated and displayed on the display 8 (S''T5).

ST8, ST9). When the sample powder measured as 1, . In this state, if you press the 100% key on the keyboard 9, the following equation (1) shows that 1 - is the average value Wo (sample weight in air), sample O, 1, and medium density ρf. and ρS, it is converted to the sample type JiWd in the medium and stored in the deposition rate register, and the deposition rate Q is calculated using the following equation (2).
[-1 is calculated (S'T'1.5TIO). In this case, the deposition rate QO is 100%, and in order to confirm that the weight Wd in the medium of the sample placed on the weighing pan 2 is the maximum deposition, the value 100% is displayed. 8, and the 100% key ON flag is turned on (STIL ST!1). After 100% is displayed, when the sample powder in the container 7 on the scale pan 2 is uniformly dispersed into the medium in the sedimentation container 6 and the tare key is pressed, the load detection Cm l at that point is The average value of the output of WO
is stored in the tare amount register as tare it, and at the same time, tare subtraction processing is performed. The deposition rate QO is calculated by dividing the tared average value wr by the series of Wd (s'V6, S T12. S T13
). Pressing this tare key means a command to start sedimentation measurement of the sample powder dispersed in the medium, and the calculated sedimentation rate QO and elapsed time 0 seconds are displayed on the display 8. , the tare subtraction ON flag is set seven times and the 100% key flag is reset (ST14). Shen'l at this point
The rate Q, 0 is naturally 0% because the average value W() after the tare weight subtraction process is O. As time passes, particles with larger diameters start to be deposited in the sedimentation pan 4, but after the tare subtraction key is pressed, the detection data d□ output from the load detection unit 1 at predetermined intervals is The tare weight is subtracted by the amount t (ST15), and each time data is taken in (0
, every 2 seconds) the counter S is incremented by one count (STlG). The tared data dO is the weight in the medium of the sediment (71 samples) in the sedimentation dish 4, and the sedimentation rate Q() is calculated by dividing this value by Wd. (ST17).

Then, the unit for displaying the elapsed time on the display 8 is selected in accordance with the deposition rate QO when the value of the counter S reaches 5, that is, when 1 second has elapsed after the start of the measurement. For example, if the deposition rate QO at that point is 1% or more, it is 1 second, 0.
The most suitable time display unit is selected according to the sedimentation speed of the sample, such as "1 second or more", 10 seconds fl'+ if less than 1 second, 1 minute mark if less than 0.1 second, and so on. The SO, Sl, and M flags are sorted seven times according to (ST22.
5T23. 5T24°5T25. S”r2G,
After S'T"27)O, the elapsed time and the product MI rate QO in that time unit are displayed moment by moment on the display 8 (ST
30. 5T35). Detection of the elapsed time 'F is based on the counter S which is incremented by one count each time the data is captured (every 0.2 seconds), and the display time is 11'.
If 1 second is selected in the digit, the counter S is reset to 0 every time the counter S reaches 5, and the counter S is reset to 0.
Increment O by 1 count and display the value of the counter SO on the display 8.S'V19°S T315. S
'r37), if 10 seconds or 1 minute is selected, each time the counter S reaches 50 or 300, the counter S is reset to O, the counter s1 or Display the value of M on the display 8 (ST20. 5T40, 5T41. 5T21.5
T44.5T45). If 1 second or 10 seconds is selected as the display time unit, the counter So or Sl is reset to 0 every time the elapsed time reaches 60 seconds.
Turn the minute counter M by 1 count 71-7 (ST
38. S”T39, ST/12.5T43)
. A state in which the elapsed time 'r and the deposition rate QO are displayed on the display 8 is shown in FIG. 3 (ta). Figure 3 (al) shows that the elapsed time after the start of sedimentation is 9 minutes and 53 seconds, and the sedimentation rate at that time is 86.2%. While the rate QO is being displayed moment by moment, the elapsed time T is converted into the settling particle diameter Dj by the following equation (3) derived from the Stokes equation (
ST47).

Dj-, r K/T...(3) However, K = 1877 t(/g (pf - ps)I
l: distance δ11 from the medium liquid level to the sedimentation type; g: acceleration of gravity; and the value of the particle fMDj is a preset value, for example, Q, 1 me! m, 0.15 μm, 0.2. c.
+m... When reaching an integer multiple of an arbitrary value or its vicinity, the deposition rate QO at that point is subtracted from the deposition rate Ql at the time when the set particle diameter is reached immediately before, and the deposition change rate ΔQO is calculated. is calculated. Then, the sedimentation rate Q□ described by -1x is stored in the first sedimentation rate register, and the first display bus flag is set (Sr4B, 5T4q).
. Note that the previous deposition rate Q1 is stored in the first deposition rate register when particle 1\Dj reaches the previous setting value, and if the particle diameter Dj reaches the setting value for the first time, the value of Ql is 0. Then, the calculated particle diameter Dj and deposition rate QO
is displayed for one second along with the auxiliary display symbol (Sr29.
S'F50. S'T'31. 5T32. 5T
33. 5T34. 5T51. 5T35°S T5
2. After S T53), Dj and sedimentation change rate ΔQQ
is displayed for one second along with the auxiliary display symbol (Sr2B,
5T55. 5T3L 5T53. 5T52.
5T32°S'r54. ST35. S
Ta2) o This Dj and the sedimentation change rate ΔQo are displayed on the display 8.
The state displayed is shown in FIG. 3(b). In Fig. 3 fbl, an auxiliary display symbol is displayed indicating that the particle diameter Dj and the deposition change rate ΔQO are displayed, and the previously set particle diameter (
For example, 15. +1 m) and the currently set particle size of 1011 m
It is displayed that there is a particle size distribution of 23.1% between the two. After the deposition rate QO and the deposition change rate ΔQQ are displayed together with the particle diameter for one second each, the elapsed time T and the deposition rate QO are displayed again every second. When the call key provided on the keyboard 9 is pressed, the particle diameter DJ is calculated by equation (3) from the elapsed time T at any point in time (ST46.ST56), and the deposition rate Q at that time is calculated.
The deposition rate Q1 at the time when the call key was pressed immediately before is subtracted from O to calculate the deposition change rate ΔQO, and it is displayed in the same procedure as when the set particle diameter is reached (Sr57
). Incidentally, the deposition rate Qo when this call key is pressed is stored in the second deposition rate register, and is used as Ql when the next time ■•I'l+low- is pressed. Figure 3 (() shows the state in which the particles i\1)j and the deposition rate Qn at that point are displayed by operating the call key. Figure 3 (
In C), when the call key is pressed, 1 is displayed, along with an auxiliary display symbol indicating that the settled particle size is 28.3/1 m and 28. ．．
It is indicated that 52.3% of the particles are distributed over 311 m. As sedimentation progresses, the sedimentation rate QQ reaches a predetermined value,
For example, when 90% is reached, the contents of all flags and registers are cleared (STI8.S'r58), so Sr4 to Sr5. Sr6. Sr7. The average value Wo (sedimented weight) is displayed by Sr1, indicating that the measurement is complete.

In this way, the weight of the sample placed on the weighing pan in the air is converted to the weight in the medium, and the amount of the sample diffused in the sedimentation container deposited in the sedimentation mold is the above-mentioned weight of the sample in the medium ♡. The deposition rate is calculated and displayed moment by moment along with the elapsed time. Further, the elapsed time is converted into a sedimentation particle size, and each time the value reaches a predetermined value, the particle size, sedimentation rate, and sedimentation change rate are held and displayed for a certain period of time. Also, press the call key at the elapsed time, Part 9.
The sedimentation particle diameter is calculated from the elapsed time at 94j, and G is held and displayed for a certain period of time along with the sedimentation rate and sedimentation change rate at that point.

As explained above, according to the present invention, the elapsed time and sedimentation rate are displayed immediately after the start of the measurement, and the elapsed time and sedimentation rate can be directly displayed. ．．
There is no need for +i. In addition, since the optimal elapsed time display unit force (is selected depending on the sedimentation rate at the initial stage of sedimentation start), there is no need to adjust the 8'A even for samples with different sedimentation velocities. When the diameter reaches the preset value, the particle diameter, sedimentation rate, and deposition changes are displayed for a certain period of time, so you can see the distribution status of the particles f') in the sample. It is possible to omit the analysis work after the measurement is completed, such as sequentially checking the J shop and fL part during the measurement.In addition, by pressing the call key, you can select the Zunawara particle at any elapsed time. diameter,
It is possible to find the deposition value of G vs. 1, especially the desired abduction diameter and its cloth range information (if the funeral is j:I), it is for Y7.

[Brief explanation of drawings]

Fig. 1 does not show the structure of the embodiment of the present invention, and Fig. 2 (i+) shows its processing program II graph. Figure (81, fill, (c
1 is an external view showing the display state of the display device of 16 examples of the present invention. ■...? 1; j weight detection section, 2... weighing plate,
4... Sedimentation dish, 5... Control section, 6... Sedimentation 1 (child container).

Claims (1)

[Claims] (]) A weighing pan, a settling mold suspended in a medium in a settling container, and the loads of the weighing pan and the settling mold are detected and digitally converted at predetermined intervals. The weight of the sample powder placed on the plate as described above is converted to the weight of the sample in the medium using the sample density and medium density that have been input in advance and is stored. The sample 15) on the above-mentioned balance plate is diffused into the above-mentioned medium, and the detected load is used as the tare amount, and subsequent load detection values are subjected to tare subtraction processing, and the process proceeds to "C above-mentioned sedimentation type" 2. means for calculating the sedimentation weight per weight of the sample; means for calculating the sedimentation rate by dividing the sedimentation weight by the weight of the sample in the medium after a measurement start signal is issued; An electronic sedimentation balance equipped with means for displaying the time elapsed from the time the start signal is generated. (2) Convert the above elapsed time T to a particle diameter Dj using the following formula, and each time the particle diameter reaches a preset value, calculate the amount based on the particle diameter at that point, the sedimentation rate, and the sedimentation rate at that point. 2. The electronic sedimentation balance according to claim 1, wherein the sedimentation change rate, which is calculated by subtracting the sedimentation rate at the time when the immediately preceding set particle diameter is reached, is held and displayed for a certain period of time. 1) j =,,r18ηI(/g(ρf−ρS)・′F
Here, η: Medium viscosity coefficient 11: Distance from the medium surface to the settling mold g: Acceleration of gravity ρr: Sample density ρS: Medium density (3) At any above elapsed time, key operation can be performed to 3. The electronic sedimentation balance according to claim 1, wherein the electronic sedimentation balance is configured to calculate particle diameter, sedimentation rate, and sedimentation change rate and hold and display them for a certain period of time. (4) The display of the elapsed time can be changed in accordance with the value of the sedimentation rate after a predetermined time has elapsed from the time when the measurement start signal is generated. The electronic sedimentation balance according to item 1, item 2, or item 3. (51lx recording measurement start signal) The first aspect of the present invention is characterized in that the signal is generated when the command key for the tare subtraction processing is pressed. The electroprecipitation bottle according to paragraph 2, paragraph 3, or paragraph 4.