JP4505158B2 - Particle size distribution measuring device and control program for particle size distribution measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a particle size distribution measuring device such as a laser diffraction / scattering particle size distribution measuring device and a control program for the particle size distribution measuring device for measuring the particle size distribution of a granular material.
[0002]
[Prior art]
In recent years, in a laser diffraction / scattering type particle size distribution measuring apparatus, there is an automatic dispersion medium supply unit that supplies a dispersion medium (also referred to as a solvent) and a cleaning liquid to a measurement unit. In addition, there is a method in which a sample solution to be measured is automatically injected and stirred to obtain a sample solution which is circulated to obtain a particle size distribution by circulation. In addition, there is a type in which a cleaning liquid is supplied after measurement so that the circulation system of the measurement unit can be cleaned.
[0003]
FIG. 4 is a diagram of an overall configuration showing an example of a particle size distribution measuring apparatus 20 that has been used conventionally. 2 is a measuring unit, 3 is a process such as a personal computer connected to the measuring unit 2 by a communication line or the like. Part.
[0004]
The measurement unit 2 includes, for example, two types of dispersion media 4a and 4b, an automatic dispersion medium supply unit (hereinafter referred to as a reservoir unit) 4 that can selectively supply the cleaning liquid 4c, and a plurality of measurement target samples S. ₁ A sample holder 5 that can sequentially put one measurement target sample Sm out of .about.Sn. Further, a mixing unit 6 that mixes the sample Sm to be measured with the dispersion media 4a and 4b to generate the sample solution S, a pump 7 that circulates the sample solution S, a cell 8 through which the sample solution S flows, A circulation system 11 is formed by an electromagnetic valve 9 for draining the sample solution S and an ultrasonic generator 10 for preventing the generation of particle lumps in each particle contained in the sample solution S.
[0005]
Further, a laser light source 12 for irradiating the cell 8 with laser light and a plurality of detectors 13 (13a to 13n) for measuring the intensity of the transmitted light Lt and scattered light Ls of the laser light are provided. Forms the optical system 14. Reference numeral 15 denotes a measurement unit that outputs a control signal and inputs a measurement value to each of the units 4 to 14 described above.
[0006]
FIG. 5 is a diagram showing an example of a setting screen Wp showing an example of setting of the measurement unit 2 executed by the processing unit 3. As shown in FIG. 5, the user can make settings related to the cleaning operation in the particle size distribution measuring apparatus 20 in advance using the setting screen Wp. The setting screen Wp shown in this example includes an input unit 21 that selects the type of liquid used for cleaning the circulation system 11 and an input unit 22 that sets the number of cleaning operations described later. In this example, the liquid used for cleaning is the dispersion medium A (that is, the dispersion medium 14a), and the number of cleanings is set to one.
[0007]
FIG. 6 shows a plurality of samples S to be measured. ₁ It is a flowchart which shows the content of the process by the control program performed by the said process part 3 when measuring the particle size distribution of -Sn sequentially. In FIG. 6, Sp1 is a step of injecting a predetermined dispersion medium into the mixing unit 6 using the reservoir unit 4 or the like, and Sp2 is agitating the injected dispersion medium using the centrifugal pump 7 or the like and in the circulation system 11 The step Sp3 is a step of performing blank measurement using the injected dispersion medium.
[0008]
Sp4 is the sample S to be measured ₁ Step of sequentially putting Sn to the mixing unit 6 using the sample holder 5 or the like, Sp5 is the sample S to be measured ₁ ~ Sn is mixed and stirred in a dispersion medium to form a sample solution S and the sample solution S is circulated in the circulation system 11, Sp6 is a step of measuring the particle size distribution of the sample solution S, Sp7 is a solenoid valve This is a step of draining the measured sample solution S by opening 9. That is, these steps Sp <b> 1 to Sp <b> 7 indicate the measurement procedure of the measurement target component.
[0009]
Sp8 is a step of injecting a liquid for cleaning the circulation system 11 into the mixing unit 6 using the reservoir unit 4 or the like (in this case, the dispersion medium 14a defined by the setting screen Wp shown in FIG. 5). Sp9 is a step of stirring the dispersion medium 4a using the centrifugal pump 7 or the like and circulating the circulation system 11 to circulate the circulation system 11, and Sp10 is a step of draining the washed dispersion medium 4a. That is, these steps Sp8 to Sp10 indicate the cleaning procedure of the circulation system 11.
[0010]
Sp11 counts the number of times after executing the cleaning procedure, and determines whether or not the cleaning procedure has been executed a predetermined number of times (in this example, once determined by the setting screen Wp shown in FIG. 5). This is a step to judge. That is, the circulation system 11 is repeatedly washed a set number of times.
[0011]
Sp12 is cleaned for a set number of times, and then all samples S to be measured ₁ Is a step of determining whether or not the particle size distribution measurement of ~ Sn has been completed, and the measurement target sample S that has not yet been measured ₁ If there is ~ Sn, the process returns to step Sp1. That is, by performing a series of processes shown in FIG. ₁ The particle size distribution of ~ Sn can be measured fully automatically.
[0012]
[Problems to be solved by the invention]
However, in the particle size distribution measuring apparatus 20 described above, when the circulation system 11 is automatically cleaned, the reference number of times of cleaning is fixed to the number of times previously input to the program (in the above example, once). As a result, it has not been possible to confirm whether the entire circulatory system 11 has been sufficiently cleaned. For this reason, it has adhesive properties such as mud and paint Strong sample After the measurement, the circulatory system is not sufficiently cleaned by the predetermined number of washings, and the data used in the previous particle size distribution measurement remains in the part where the circulatory system tends to accumulate. It was a vicious circle and could not be measured accurately.
[0013]
In such a case, it may be considered that apparently sufficient cleaning is performed by wiping off the dirt in the cell 8. Since it is often a part away from the cell 8 such as the vicinity of the generator 10, the measurement value may become inaccurate due to mixing of the samples used in the previous particle size distribution measurement.
[0014]
Further, if the number of cleanings is increased in order to sufficiently wash the circulatory system 11, the cleaning liquid and the washing time are increased by repeating extra washing even though the circulatory system is actually washed sufficiently. Would be wasted. A large number of samples S to be measured ₁ When measuring -Sn, it was inevitable that the waste time for cleaning became a big problem.
[0015]
The present invention relates to a particle size distribution measuring device and a particle size distribution measuring device that automatically determine the degree of contamination of a circulating system including cells and automatically perform cleaning until the amount of contamination is sufficiently reduced in the particle size distribution measuring device. The purpose is to provide a control program.
[0016]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the particle size distribution measuring device of the present invention includes an automatic dispersion medium supply unit that supplies a dispersion medium or a cleaning liquid, and a sample to be measured mixed and stirred in the dispersion medium to generate a sample solution. A circulation system for circulating the sample solution to the cell; Circulated to cell An optical system having a light source for irradiating the sample solution with light and a detector for measuring the intensity of transmitted light and scattered light from the light source; After draining the sample solution from the circulation system after measurement, From automatic dispersion medium supply unit In the circulatory system Supply dispersion medium or cleaning liquid Then A cleaning operation is performed by circulating the dispersion medium or cleaning liquid in the circulation system and stirring and washing. Sequentially The processing unit to perform And the processing unit is configured to determine the degree of contamination of the circulation system after being agitated and washed based on the output of the detector, and it is determined that the degree of contamination has not reached a predetermined value or less. If it is determined that the means for repeating the cleaning operation, the degree of contamination has reached the predetermined value or less, the cleaning operation is stopped and the dispersion medium or cleaning liquid used for the cleaning operation is drained from the circulation system, Means to prepare for the next measurement (Claim 1).
[0017]
In the above-described present invention, even if no person is present, the apparatus can automatically determine the degree of contamination of the circulatory system including the cell based on the output of the detector, and can repeatedly perform an appropriate cleaning operation. . The degree of contamination of the circulatory system is determined based on the output of a detector that measures the intensity of transmitted light, reflected light, and scattered light. Therefore, at least one of transmitted light, reflected light, and scattered light is determined. It is possible to accurately determine the degree of contamination of the circulatory system using one intensity. Further, the stirring and cleaning of the circulation system using the dispersion medium or the cleaning liquid can stir and remove the measurement target sample remaining in the entire circulation system, thereby cleaning the entire circulation system including the cells.
[0018]
That is, by performing the cleaning operation as in the present invention, it is possible to reliably prevent the previous measurement target sample from being mixed at the stage of measuring the particle size distribution of the next measurement target sample, and data obtained by automatic measurement. Reliability is improved. Also, The processing unit is Dirty degree of circulatory system Since the cleaning operation and its repetition are stopped when it is determined that the temperature has reached a predetermined value or less set in advance, the circulation system is sufficiently cleaned so as not to adversely affect the next particle size distribution measurement. Since the cleaning operation can be stopped at this stage, the repetition of the cleaning operation can be suppressed to a length suitable for the actual situation, and the measurement time can be shortened accordingly. It is possible to eliminate waste of cleaning liquid and cleaning time due to extra cleaning. Furthermore, since the cleaning operation can be easily performed using an existing hardware configuration, cost reduction can be achieved. The cleaning operation may be repeated by increasing the number of repetitions of the series of operations or by increasing the time for performing the stirring and cleaning of the circulation system.
[0019]
It has a sample holder that can hold a plurality of measurement target samples and can supply each measurement target sample to the circulation system, and has the following operations: supply of dispersion medium, circulation of dispersion medium, blank measurement, It is possible to measure the particle size distribution of multiple samples to be measured sequentially by loading the sample to be measured, stirring and circulating the sample to be measured, measuring the particle size distribution, draining the sample solution, and performing the washing operation in order. In this case (claim 2), it is possible to sequentially measure the particle size distribution of a plurality of measurement target samples. Also in this case, since the length of the cleaning operation is adjusted according to the type of the sample to be measured, time is not wasted for useless cleaning.
[0020]
The processing unit In Dirt on the circulatory system The degree judgment means The transmittance of transmitted light obtained from the output of the detector is predetermined. Set Predetermined value Whether or not to decide Is set to Case (Claim 3) and the processing unit In The scattered light obtained from the output of the detector by the means for determining the degree of contamination of the circulatory system Strength is preset Predetermined value Whether or not Judge Is set to In the case (Claim 4), contamination of the circulatory system can be accurately determined. In particular, an existing optical system can be used as a detector for obtaining an output used as a criterion for determination as long as it is a particle size distribution measuring apparatus. Therefore, the above-described contamination determination requires an additional hardware configuration. It can contribute to cost reduction.
[0021]
The detector for judging contamination of the circulatory system is not limited to diverting an optical system for particle size distribution measurement, and a separate light source and detector may be provided at an appropriate place in the circulatory system. Needless to say, it is good. In this case, it is possible to more reliably detect the absence of residual particles in the circulation system by providing an optical system for dirt detection at a place where dirt is most likely to adhere in the circulation system. .
[0023]
The control program of the particle size distribution measuring apparatus of the present invention includes an automatic dispersion medium supply unit that supplies a dispersion medium or a cleaning liquid, and a sample to be measured mixed and stirred in the dispersion medium to generate a sample solution. A circulating system, an optical system having a light source for irradiating light to the sample solution circulated in the cell, a detector for measuring the intensity of transmitted light and scattered light from the light source, and supply of the automatic dispersion medium A control program for a particle size distribution measuring apparatus having a unit, a circulation system, and a processing unit for controlling an optical system, the control program comprising: Ru The sample solution is drained from the circulation system after measuring the intensity of the transmitted light and scattered light. After The dispersion medium or cleaning liquid is supplied from the automatic dispersion medium supply unit, and the dispersion medium or cleaning liquid is circulated to the circulation system. Seduction Agitation washing, We perform washing operation to drain this sequentially Determining the degree of contamination of the circulation system after being agitated and washed based on the output of the detector, and if it is determined that the degree of contamination has not reached a predetermined value or less, Said When the cleaning operation is repeated and the degree of contamination is determined to have reached the predetermined value or less, a series of processes for stopping the cleaning operation and draining the dispersion medium or cleaning liquid used for the cleaning operation from the circulation system is performed. According to the fifth aspect of the present invention, they are programmed so as to be executed sequentially.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
The particle size distribution measuring apparatus 1 of the present invention is formed with the same hardware configuration as the conventional particle size distribution measuring apparatus 20 shown in FIG.
The sample holder 5 constituting the particle size distribution measuring apparatus 1 of the present invention includes, for example, a measurement target sample S. ₁ .About.Sn, each of the 24 cups 5a rotates around the rotation shaft 5b, and the measurement target sample S is instructed by an instruction from the personal computer 3 (processing section). ₁ To Sn are sequentially charged into the mixing unit 6.
[0025]
FIG. 1 is a diagram showing an example of a setting screen W showing a setting example of the measuring unit 2 by the personal computer 3 of the laser diffraction / scattering particle size distribution measuring apparatus 1 of the present invention. FIG. 2 is a setting screen shown in FIG. In accordance with the setting of W, the personal computer 3 executes the control program P and a plurality of measurement target samples S ₁ It is a figure which shows the procedure when measuring the particle size distribution of -Sn sequentially.
[0026]
As shown in FIG. 1, the user can make settings related to the cleaning operation in the particle size distribution measuring apparatus 1 in advance using a setting screen W. The setting screen W shown in this example includes an input unit 16 for selecting the type of liquid used for cleaning the circulation system 11 and a reference input unit 17 for repeating a cleaning operation used when performing a cleaning operation described later. Have.
[0027]
In the setting shown in this example, the dispersion medium A is selected as the liquid used for stirring and cleaning described later, and the sample S to be measured from the automatic dispersion medium supply unit 4 during the cleaning operation of the circulation system 11. ₁ It is set so that the same dispersion medium 4a as that when measuring the particle size distribution of ~ Sn is supplied. In addition, it is set so that the determination of whether or not the cleaning operation needs to be continued by detecting the contamination of the circulation system 11 (described as “rinse standard”) is performed based on the transmittance. In this example, the circulation system 11 may be free from contamination when the transmittance is 99% or more (100% when there is no cell contamination) from the measured value of the transmitted light Lt by the detector 13a ( In other words, it is determined that it has been sufficiently washed).
[0028]
The example shown in FIG. 1 shows an example of setting in the particle size distribution measuring apparatus 1 of the present invention, and does not limit the present invention. That is, for example, the dispersion medium used for the cleaning operation may be a dispersion medium 4b different from the dispersion medium 4a used when the particle size distribution measurement is performed, or the cleaning liquid 4c may be used. Furthermore, the reservoir unit 4 may be able to select more types of dispersion media or cleaning liquids, and the dispersion medium used for the cleaning operation may be changed in accordance with the degree of dirt removal.
[0029]
Further, the detection of the cleaning state is not limited to the transmittance of the transmitted light Lt, and may be determined by the intensity of the scattered light Ls or the reflected light. Furthermore, it is also conceivable to set the detection of the cleaning state based on a combination of two or more measured values of transmitted light Lt, scattered light Ls, or reflected light outside the figure. In the case where the cleaning state is detected based on the intensity of the scattered light Ls or the reflected light, the cleaning can be completed assuming that the dirt can be sufficiently removed when the value becomes a predetermined value or less. Furthermore, it can be set to determine whether or not to continue the cleaning operation from the degree of change in the intensity of transmitted light, scattered light, and reflected light before and after the cleaning operation.
[0030]
In addition, in this example, the setting screen W or the like can be used to set the type of the dispersion medium used for the cleaning liquid and the reference for detecting the cleaning state of the circulation system. Needless to say, it may be determined in advance.
[0031]
FIG. 2 shows a plurality of measurement samples S. ₁ It is a flowchart which shows the content of the process of the control program P which the personal computer 3 performs when measuring the particle size distribution of -Sn sequentially. The processing contents shown in FIG. 2 will be described below with reference to FIG.
[0032]
In FIG. 2, S <b> 1 is a step of injecting water (hereinafter simply referred to as water 4 a) as a dispersion medium 4 a for particle size distribution measurement into the mixing unit 6 using the reservoir unit 4. That is, the reservoir unit 4 that has received a command from the personal computer 3 has an electromagnetic valve 4d for taking out the water 4a (the reservoir unit 4 also has electromagnetic valves 4e and 4f for taking out the dispersion medium 4b and the cleaning liquid 4c. And the pump 4g is driven to inject water 4a into the mixing unit 6 and supply water until the floating ball 4h reaches a predetermined height. 4i is a controller that controls the solenoid valves 4d to 4f and the pump 4g by checking the water level from the position of the floating ball 4h.
[0033]
S <b> 2 is a step of stirring the injected water 4 a using the centrifugal pump 7 and the like and circulating the water 4 a into the circulation system 11. By this step S1, the water 4a is filled in the circulation system 11, and bubbles mixed in the circulation system 11 can be removed.
[0034]
S3 is a step of performing blank measurement using the injected water 4a. The intensities of the transmitted light Lt and the scattered light Ls obtained for the blank measurement are used in the calculation of the particle size distribution and stored in the personal computer 3.
[0035]
S4 is the sample S to be measured ₁ In this step, the sample Sm to be measured is sequentially put into the mixing unit 6 using the sample holder 5 from .about.Sn.
[0036]
S5 is a step in which the sample solution Sm is mixed and stirred in the water 4a to form the sample solution S and the sample solution S is circulated in the circulation system 11. That is, by driving the pump 7 in accordance with a command from the personal computer 3, the sample 4 to be measured can be mixed in the water 4a and can be circulated in the circulation system 11 while stirring it.
[0037]
In addition, the particle size distribution measuring apparatus 1 of this example prevents the formation of a lump of the measurement target sample Sm by driving the ultrasonic transmitter 10, and the sample solution S circulating in the circulation system 11 is sufficient. It is comprised so that it may be disperse | distributed to and stirred.
[0038]
S6 is a step of measuring the particle size distribution of the sample solution S. That is, when the sufficiently stirred sample solution S circulates in the circulation system 11, the laser light is irradiated from the laser light source 12 to the cell 8 according to a command from the personal computer 3, and the intensity of the transmitted light Lt and each scattered light Ls generated at that time. Are detected by the detectors 13a to 13n. The output of the detectors 13a to 13n is taken into the personal computer 3 and analyzed, whereby the particle size distribution of the measurement target sample Sm is obtained.
[0039]
S7 is a step of draining the measured sample solution S by opening the electromagnetic valve 9. That is, these steps S <b> 1 to S <b> 7 indicate the measurement procedure of the measurement target component. When the measurement target sample Sm is not an adherent particle, almost all the measurement target sample Sm is discharged by the waste water in step S7, so that almost no particles are left in the circulation system 11. However, when the measurement target sample Sm is adhesive particles such as mud or paint, some particles are left in the circulation system 11.
[0040]
S8 is a liquid for cleaning the circulation system 11 in the mixing unit 6 using the reservoir unit 4 or the like (in this case, since the dispersion medium A is selected on the setting screen W shown in FIG. 1, the water 4a is used. This is a step of injecting.
[0041]
S9 is a step of stirring and washing the circulation system 11 by stirring the water 4a using the centrifugal pump 7 and the like and circulating it in the circulation system 11, that is, used for measuring the particle size distribution of the sample Sm to be measured. The same dispersion medium 4a (water) as above is circulated through the circulation system 11 to be stirred and washed. Normally, sufficient washing can be performed by using the same dispersion medium 4a used in the particle size distribution measurement in step S9 of the stirring washing. However, in this step S9, the washing liquid 4c or the like is used. It is also possible to increase the cleaning power.
[0042]
S10 is a blank measurement performed using the water 4a after stirring and washing. At this time, when the measurement target sample Sm is hardly left in the circulation system 11, the transmitted light Lt having almost the same transmittance as that of the blank measurement in Step S3 is obtained, and the scattered light Ls almost zero is detected. . However, when the measurement target sample Sm remains in the circulation system 11, the transmitted light Lt becomes weak and the scattered light Ls becomes strong. Therefore, the personal computer 3 records the result of the blank measurement in step S10.
[0043]
S11 is a step of draining the washed water 4a. That is, the measurement target sample Sm dropped from the circulation system 11 by the stirring and washing step S9 is discharged. That is, these steps S8 to S11 indicate the cleaning operation of the circulation system 11.
[0044]
S12 is a step of determining the degree of contamination of the circulation system 11 based on the measurement value of the step S10. In the case of this example, as shown in the setting screen W of FIG. 1, the degree of contamination is determined by the measured value of the transmitted light Lt being 99% or more of the value at the time of the blank measurement in step S3. If the measured value of the transmitted light Lt does not reach 99%, it is determined that the degree of contamination is large, and the cleaning operation from step S8 is repeated once again.
[0045]
By determining the degree of contamination of the circulation system 11 based on the measured value of the transmitted light Lt in the blank measurement after the circulation cleaning of the circulation system 11, the contamination in the entire circulation system 11 can be determined. It is possible to reliably determine whether or not the measurement can be performed. Although not described in this example, it is possible to accurately determine the degree of contamination of the circulation system 11 from the measured values of the scattered light Ls and the reflected light.
[0046]
The cleaning operations S8 to S11 for performing the circulating cleaning are repeatedly performed according to the cleaning state of the circulation system 11 until the degree of contamination is sufficiently reduced. Therefore, when almost no measurement target sample Sm remains in the circulation system 11 during drainage. In some cases, the cleaning operation S8 to S11 may be performed once, but in the case of the adherent measurement target sample Sm, it may be necessary to perform the cleaning operation several times continuously. In any case, since the minimum necessary cleaning can be performed, the entire circulation system 11 is prevented while avoiding wasteful use of the dispersion media 4a and 4b and the cleaning liquid 4c associated with increasing the number of cleaning operations S8 to S11. Thorough cleaning can be performed.
[0047]
S13 is all measurement target samples S ₁ Is a step of determining whether or not the particle size distribution measurement of ~ Sn has been completed, and the measurement target sample S that has not yet been measured ₁ If ~ Sn remains, the process can be returned to the step S1 to proceed to the next measurement. That is, by performing a series of processes shown in FIG. 2, the particle size distribution measuring apparatus 1 has a plurality of measurement target samples S without an operator. ₁ The particle size distribution of .about.Sn can be measured automatically and the measurement results can be stored in the personal computer 3.
[0048]
In the case of this example, since the same water 4a as the dispersion medium used for measuring the particle size distribution is used for cleaning the circulation system 11, the blank measurement in step S10 is performed in step S3 according to the determination in step S13. If it can be determined that the circulatory system 11 has been cleaned to the same extent as the measurement, the process is skipped to step S4 as indicated by the phantom arrow, and blank measurement is performed among steps S1 to S7 indicating the measurement procedure. It is also possible to skip the steps S1 to S3 and move to the next measurement.
[0049]
Further, although the cleaning operations S8 to S11 show an example in which the repetition of the cleaning operations S8 to S11 is adjusted by changing the number of repetitions, the time for executing step S9 for performing the agitation cleaning is increased. The repetition of the cleaning operations S8 to S11 may be adjusted.
[0050]
FIG. 3 is a diagram showing another example of the cleaning operation. In FIG. 3, step S7 for draining is the same as step S7 in FIG. That is, FIG. 3 shows an operation following step S7 in FIG.
[0051]
In FIG. 3, S14 is a step of injecting the same dispersion medium (for example, water 4a) as the dispersion medium used for particle size distribution measurement into the circulation system 11, S15 is a step of stirring and washing the water 4a, and S16 is stirring and washing. A step of performing blank measurement using the subsequent water 4a, S17 is a step of draining the measured water 4a. The detailed operations of these steps S14 to S17 are almost the same as those of steps S8 to S11 already described in detail.
[0052]
Next, S18 is a step in which the blank measurement in step S16 is compared with the previous blank measurement to detect the amount of change in dirt. That is, when performing the first cleaning, the result of the blank measurement in step S3 shown in FIG. 2 before the particle size distribution measurement is compared with the transmittance to determine whether a large amount of dirt is attached. to decide. If the change amount of the dirt level is small, the process jumps to step S13 in FIG. 2 to prepare for the next measurement.
[0053]
If it is determined in step S18 that the amount of change in dirt is large, the reservoir unit 4 executes a step of supplying the cleaning liquid 4c to the mixing unit 6 according to a command from the personal computer 3. (Step S19)
[0054]
S20 is a step of stirring the cleaning liquid 4c using the centrifugal pump 7 to clean the circulation system 11, and S21 is a step of draining the cleaning liquid 4c. When the cleaning operations S19 to S21 using the cleaning liquid 4c are completed, the process jumps to step S14, and the cleaning operations S14 to S17 using the water 4a are executed again.
[0055]
In the subsequent step S17, the result of the blank measurement in the previous step S16 and the result of the blank measurement in the current step S16 are compared, and the process jumps to step S13 in FIG.
[0056]
As shown in this example, by using the amount of change in dirt, it is determined whether or not to continue the cleaning operation, so that the dirt that does not fall off even by the cleaning operation as shown in steps S14 to S21 can be used forever. Repeating the cleaning operation can be eliminated. In other words, the next sample S to be measured ₁ At the time of measurement of particle size distribution measurement using ~ Sn, the sample S to be measured ₁ The cleaning operation can be terminated if it is dirt that is not likely to be mixed into ~ Sn.
[0057]
Even if a limited value is provided for the number of times of cleaning, and the circulating system 11 is not cleaned even after the limited number of times of cleaning, various modifications such as issuing a warning of occurrence of an abnormality can be considered.
[0058]
Further, in the step S20 of stirring and washing using the above-described washing liquid, the washing operation can be repeated by adjusting the length of the washing time according to the size of the dirt. Similarly, the cleaning operation may be repeated depending on the length of the cleaning time in the above-described steps S9 and S15 of the stirring cleaning.
[0059]
Moreover, each example mentioned above is the measurement object sample S. ₁ There are a plurality of Sn, and each measurement target sample S ₁ Although the particle size distribution measuring apparatus 1 that automatically measures the particle size distribution of ~ Sn is illustrated, the present invention may also be used when measuring the particle size distribution of one sample to be measured. Needless to say.
[0060]
In addition, in each of the above-described examples, in the cleaning operation, after supplying the dispersion medium or the cleaning liquid, the supplied dispersion medium or the cleaning liquid is circulated through the circulation system to perform stirring cleaning. An example of the cleaning operation for draining the cleaning liquid is shown, and this makes it possible to perform the cleaning while minimizing the waste of the dispersion medium or the cleaning liquid, but the present invention is not limited to this.
[0061]
That is, the cleaning operation of the present invention supplies the dispersion medium or cleaning liquid and circulates the supplied dispersion medium or cleaning liquid to the circulation system to perform stirring cleaning, and simultaneously drains some of the stirring medium cleaned or cleaning liquid. It may be a thing. In this case, repeated washing with stirring can be performed by increasing the washing time. Further, in this case, the personal computer 3 performs the cleaning operation, and checks the degree of contamination of the circulation system 11 including the cell 8 based on the light transmittance and the scattered light intensity, and the contamination of the cell becomes below a certain value. Sometimes it has a function of stopping the cleaning operation.
[0062]
The control program P may be incorporated in the personal computer 3 in advance, but the control program P is recorded on a recording medium such as a CD-ROM or a floppy disk, and the conventionally used particle size is used. Needless to say, the control program P for executing the above-described processing may be installed in the processing unit of the distribution measuring apparatus 20. Furthermore, it goes without saying that the processing unit 3 for executing the control program P can be variously modified such as a microcomputer built in the measuring unit 2.
[0063]
【The invention's effect】
The particle size distribution measuring device and the control program for the particle size distribution measuring device of the present invention determine the degree of contamination from the intensity of transmitted light, scattered light, etc. in a predetermined part in a circulation system such as a cell, and adjust to the degree of contamination. Since the entire circulatory system is cleaned, it is possible to surely remove dirt that adversely affects the analysis of the next sample to be measured, and to eliminate waste of cleaning liquid and cleaning time due to extra cleaning. Therefore, even if the operator is not attached, the particle size distribution measuring device automatically determines the degree of contamination and performs appropriate cleaning, so that the reliability of the measured value can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a setting screen of a particle size distribution measuring apparatus of the present invention.
FIG. 2 is a diagram showing a flow of processing by a control program for analyzing a plurality of samples to be measured using the particle size distribution measuring apparatus of the present invention.
FIG. 3 is a diagram showing another example of a cleaning operation by the particle size distribution measuring apparatus.
FIG. 4 is a diagram showing an overall configuration of a particle size distribution measuring apparatus.
FIG. 5 is a diagram illustrating an example of a setting screen of a conventional particle size distribution measuring apparatus.
FIG. 6 is a diagram illustrating a measurement procedure for analyzing a plurality of samples to be measured using a conventional particle size distribution measuring apparatus and a flow of processing of a cleaning operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Particle size distribution measuring apparatus, 3 ... Processing part, 4 ... Automatic dispersion medium supply unit, 4a, 4b ... Dispersion medium, 4c ... Cleaning liquid, 5 ... Sample holder, 8 ... Cell, 11 ... Circulation system, 12 ... Light source, 13a to 13n: detector, 14: optical system, P: control program, S: sample solution, S ₁ ~ Sn, Sm ... sample to be measured, S8 to S12, S14 to S21 ... cleaning operation.

Claims (5)

An automatic dispersion medium supply unit for supplying a dispersion medium or a cleaning liquid, a circulation system for mixing and stirring a sample to be measured in the dispersion medium to generate a sample solution, and circulating the sample solution to the cell;
An optical system having a light source for irradiating light to the sample solution circulating in the cell, and a detector for measuring the intensity of transmitted light and scattered light from the light source;
After the measurement, drain the sample solution from the circulation system, supply the dispersion medium or cleaning liquid from the automatic dispersion medium supply unit to the circulation system, circulate the dispersion medium or cleaning liquid to the circulation system, perform agitation washing, and drain A processing unit for sequentially performing cleaning operations,
The processing unit is a means for determining the degree of contamination of the circulatory system after being agitated and washed based on the output of the detector, when it is determined that the degree of contamination has not reached a predetermined value or less, Means for repeating the cleaning operation, when it is determined that the degree of contamination has reached the predetermined value or less, the cleaning operation is stopped and the dispersion medium or cleaning liquid used for the cleaning operation is drained from the circulation system, and the next measurement is performed. A particle size distribution measuring apparatus, comprising:   It has a sample holder that can hold a plurality of measurement target samples and can supply each measurement target sample to the circulation system, and supply of a dispersion medium, circulation of the dispersion medium, blank measurement, input of the measurement target sample, The particle size distribution of a plurality of measurement target samples can be sequentially measured by sequentially performing stirring and circulation of the measurement target sample, measurement of the particle size distribution, draining of the sample solution, and the cleaning operation. Particle size distribution measuring device.   The means for determining the degree of contamination of the circulatory system in the processing unit is set to determine whether or not the transmittance of transmitted light obtained from the output of the detector has reached a predetermined value set in advance. The particle size distribution measuring apparatus according to claim 1 or 2.   The determination unit for the degree of contamination of the circulatory system in the processing unit is set to determine whether or not the intensity of scattered light obtained from the output of the detector has reached a predetermined value set in advance. The particle size distribution measuring apparatus according to claim 1 or 2. An automatic dispersion medium supply unit for supplying a dispersion medium or a cleaning liquid, a circulation system for mixing and stirring a sample to be measured in the dispersion medium to generate a sample solution, and circulating the sample solution to the cell, and a sample to be circulated to the cell An optical system having a light source for irradiating the solution with light, a detector for measuring the intensity of transmitted light and scattered light from the light source, the automatic dispersion medium supply unit, the circulation system, and a processing unit for controlling the optical system; A control program for a particle size distribution measuring apparatus having
After the sample solution after the measurement of the intensity of the transmitted light and the scattered light that due to the detector the light was drained from the circulation, the dispersion medium or the cleaning liquid is supplied to the dispersion medium or cleaning liquid from the automatic dispersion medium supply unit the performs circulated allowed攪拌cleaning the circulatory system, which sequentially performs a washing operation for draining, to determine the contamination degree of the circulation system after being stirred cleaned on the basis of the output of the detector, dirt degree If but which are determined not to reach the following preset predetermined value, the cleaning operation of repeating, if the dirty degree is determined to have reached to be not more than the predetermined value, the cleaning operation the cleaning operation is stopped A control program for the particle size distribution measuring apparatus, wherein the processing unit is programmed to sequentially execute a series of processes for draining the dispersion medium or cleaning liquid used in the circulation system from the circulation system. .

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