JPH06201560A - Automatic measuring apparatus for amount of mass change - Google Patents

Abstract

(57) [Summary] [Objective] To provide a low-cost, highly reproducible and highly reliable mass change amount automatic measurement device that eliminates the variation in the mass change amount due to the arrangement position of the sample in the heating dryer. [Structure] In a heating dryer containing a plurality of samples, an environment sensor is arranged in each of a plurality of sample placement positions, or one of a plurality of regions, and the setting is performed based on the output of each environment sensor. An arithmetic means for correcting the drying time is provided, and the heating and drying time of the sample is automatically adjusted for each region corresponding to each environment sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to automatically measure the change in mass of a sample before and after heating so that, for example, the volatile content, moisture content, ash content, etc. of the sample can be derived automatically. Regarding measuring device.

[0002]

2. Description of the Related Art Generally, it is possible to calculate the moisture content and volatile content of a sample by measuring the change in mass before and after heating and drying the sample. A device that automatically and consistently includes sample handling operations has already been put into practical use.

This type of conventional apparatus is equipped with a mass measuring unit such as an electronic balance, a heating and drying device, a handling mechanism, and a setting device for measuring conditions such as heating time, and the sample mass before the heating and drying process is measured. After that, the sample is conveyed into the heat dryer by the handling mechanism, and after the set heat drying time has elapsed, the sample is taken out from the heat dryer by the handling mechanism and the mass is measured again.

In such a conventional apparatus for automatically measuring the amount of mass change, the heating and drying time of the sample is often long, so that a large number of samples can be accommodated in the heating and drying device for measurement. We are working to improve efficiency. In addition, the temperature inside the heating dryer is usually controlled based on the output of a temperature sensor placed inside the dryer, and a fan for stirring the internal atmosphere is used in order to make the temperature inside the heating dryer uniform. There are also those with a fan for circulating hot air.

[0005]

By the way, since the heating / drying device generally has temperature unevenness, a sample containing a large number of samples may have a different sample temperature depending on the arrangement position of the samples even if the heating time is the same. The total amount of heat received by will greatly differ, and the amount of change in mass will differ depending on the position placed in the heating dryer. In addition, when the temperature of the inner wall of the dryer becomes high, infrared rays are radiated from the inner wall, but the amount of infrared rays received by the sample also differs depending on the arrangement position in the dryer, especially when heating while drawing a vacuum. When a so-called vacuum dryer for drying is used, the influence thereof becomes great, which is one of the causes of deteriorating the reproducibility of the measured value of the mass change amount.

[0006] Here, in the case where a fan for stirring the atmosphere or circulating hot air is provided in the heating dryer, although it is slightly effective in eliminating the temperature unevenness, the difference in the infrared radiation amount cannot be eliminated. Not only that, the amount of air received by the sample differs depending on the position in the dryer, which also causes a variation in the measurement results.

The present invention has been made in view of the above circumstances, and eliminates the difference in the amount of change in mass due to the position of the sample in the heating and drying device, which results in high efficiency and variation in measurement results. It is intended to provide an automatic measuring device for a small amount of mass change.

[0008]

In order to achieve the above object, in the mass change amount automatic measuring apparatus of the present invention, one or a plurality of sample placement positions in a heating dryer containing a plurality of samples. Each area is provided with an environment sensor consisting of at least one of a temperature sensor, an air volume or wind speed or pressure sensor, and an infrared sensor, and is set by a setting device based on the output from each environment sensor. Provided with a calculation means for correcting the heating and drying time,
For each sample placement position in the area corresponding to each environmental sensor,
The heating and drying time of the sample is automatically adjusted.

Here, the type of the sensor to be arranged as the environment sensor should be determined according to the type of the heating / drying device to be used. For example, in a drying device having a fan for stirring the atmosphere, an air flow rate or a wind speed or wind pressure sensor is used. An infrared sensor needs to be provided in a drier having a large amount of infrared radiation from the inner wall, and only a temperature sensor is required if these factors can be ignored.

[0010]

According to the present invention, in the case where the temperature inside the heating dryer and the stirring fan are provided, the influence of the air volume (or wind speed or air pressure) received by each sample and the amount of radiant infrared rays are large. In that case, instead of making the amount of infrared rays received by the sample uniform, measure environmental factors such as temperature unevenness, air volume unevenness, infrared unevenness in multiple areas in the dryer, and set according to the measurement results. The heating and drying time is adjusted for each area.

That is, the inside of the heating dryer is divided into a plurality of regions consisting of one or a plurality of sample arrangement positions, an environment sensor is arranged for each region, and the detection result of each of the environmental factors is determined. By correcting the set heating and drying time for each area, the variation in the measurement result due to the temperature unevenness and the air volume unevenness in the heating dryer can be eliminated.

[0012]

1 is a block diagram showing the configuration of an embodiment of the present invention. A sample transfer robot 3 is arranged between the electronic balance 1 for measuring the sample mass and the heating / drying device 2. The sample transfer robot 3 is based on a control signal from the actuator controller 10 (Not shown) Transfer the sample prepared on the electronic balance 1, transfer the sample on the electronic balance 1 into the heating dryer 2, transfer the sample in the heating dryer 2 onto the electronic balance 1. The transfer and the transfer of the sample on the electronic balance 1 to the sample rejection unit (not shown) can be performed.

The heating dryer 2 is a hot-air circulating dryer in this embodiment, and includes a heater 21 and a motor 22.
Therefore, while having the fan 23 that is given rotation,
There are three stages of sample mounting shelves A to C inside, and two samples W can be placed on each of the sample mounting shelves A to C. The heater 21 is driven and controlled by a signal from the temperature adjusting circuit 24. In the temperature adjusting circuit 24, a temperature sensor 25 is provided at an appropriate place in the heating dryer 2 for detecting a representative temperature in the dryer. Is introduced to control the heater 21 so that the temperature in the heating dryer 2 matches the set temperature.

The heating dryer 2 is provided with an automatic door 26 that can be opened and closed by driving a motor or the like.
The automatic door 26 is used for the actuator controller 10
In response to a control signal from, the sample transfer robot 3 opens and closes in synchronization with the sample loading / unloading operation.

Environmental sensor units 4A to 4C are provided at the central portions of the respective stages A to C of the heat dryer 2. Each of the environment sensor units 4A to 4C includes a temperature sensor, an air flow sensor, and an infrared sensor, and their outputs are incorporated in the control unit 5.

The control unit 5 includes each environmental sensor unit 4A.
4C, the electronic balance 1, the actuator controller 10 and the temperature adjusting circuit 24 described above are connected, and the keyboard 6 for setting the measurement conditions such as the temperature of the heat dryer 2 and the heat drying time, the measurement conditions and A CRT 7 and a printer 8 for displaying and printing measurement results and the like are connected.

The control unit 5 collects the sample weight before drying and the sample weight after drying from the electronic balance 1 to obtain the moisture content and the like, and outputs the data to the CRT 7 and the printer 8 together with the measurement conditions and the keyboard 6 and the keyboard 6. From the measurement conditions input from the above, the heating time after correction described below, and the mass before drying of each sample together with the arrangement position in the dryer 2 and the like, from the environment sensor units 4A to 4C. Based on the correction coefficient calculation unit 53 that calculates the drying time correction coefficients α _{A to} α _C described later based on the output, the correction coefficient calculated by the correction coefficient calculation unit 53, and the heating and drying time set via the keyboard 6. It is composed of a drying time calculation unit 54 that calculates the time to be actually heated and dried, and a timer unit 55. Although the control unit 5 is shown here as a block diagram for each function of each unit, it is actually composed of a microcomputer and peripheral devices such as an AD converter and various interfaces.

Next, the operation of the above embodiment of the present invention will be described. First, prior to the measurement, the measurement conditions such as the heating and drying temperature and the heating and drying time t are input from the keyboard 6 to activate the system.

When a start command is given to the system, the sample transport robot 3 sequentially mounts the samples W ... W prepared on the sample table on the electronic balance 1 and after measuring the mass of each sample before drying, Each of them is transferred into the heating dryer 2. The mass data of each sample is stored in the storage unit 52 together with the sample arrangement position in the dryer 2 and the timing data of the timing unit 52 at the time of transfer.

During this time, the outputs of the environmental sensor units 4A to 4C provided in each stage of the heating dryer 2 are sampled moment by moment, and the temperatures T _A , T _B , and T _C in the vicinity of the respective sensor units 4A to 4C are sampled. , Air amounts W _A , W _B , W _C , and infrared amounts IR _A , IR _B , IR _C are stored in the storage unit 52 in the control unit 5.

The correction coefficient calculation unit 53 uses these data, based on the following equations (1) to (3), and the drying time correction coefficient α for each stage in which the environmental sensor units 4A to 4C are placed. Find _A ~ α _C.

Α _A = f (T _A , W _A , IR _A ) ... (1) α _B = f (T _B , W _B , IR _B ) ... (2) α _C = f ( T _C, W _C, where IR _C) ···· (3), for the practical use function f, but determined based on the structure of the heating dryer 2 to be used, qualitatively, the temperature data T is When the temperature is higher than the set temperature, the value of the coefficient α is small, and when the individual air volume data W is larger than the average value of all the air volume data, the value of the coefficient α is small. A function is used that reduces the value of the coefficient α when it is larger than the average value of infrared data. The degree of influence of each data on the magnitude of the coefficient α is based on an experiment or the like in which the same sample is placed on each part, so that the variation in the mass change amount due to the difference in the stages in the heating dryer 2 becomes constant in advance. Determine empirically.

The drying time correction coefficients α _A , α _B and α _C of each stage thus obtained are sent to the drying time calculating section 54, and the following (4) to (6) using these coefficients are used. By the calculation of the equation, the previously set heating and drying time t is corrected,
The actual heat-drying times τ _A , τ _B and τ _{C of} the sample W placed on each of the stages _{A to C} are obtained.

Τ _A = α _A × t ··· (4) τ _B = α _B × t ··· (5) τ _C = α _C × t ··· (6) Each heating after correction The drying times τ _A , τ _B and τ _C are stored in the storage unit 52. Then, the corrected heating and drying time is sent to the actuator controller 10, and the sample W
Is the time τ _A , τ corresponding to each placed stage
_When only _B or τ _C stays in the heating dryer 2, the sample is transferred to the electronic balance 1 by the sample transfer robot 3, and the mass after drying is measured.

The data processing unit 51 calculates the amount of change or the rate of change of the mass of each sample before and after drying, and the result is calculated along with the corrected heating and drying time corresponding to each of the samples.
The image is displayed or printed on the RT 7 or the printer 8.

According to the embodiment of the present invention as described above, even if the environments such as the temperature, the air flow rate, the infrared radiation amount, etc. in each stage in the heating dryer 2 are different from each other, depending on the detection result of each environment. The drying time is automatically corrected for each stage, and the occurrence of measurement error due to the sample arrangement position in the dryer 2 is suppressed.

It should be noted that the sensor for detecting the air volume may be a sensor for detecting the wind speed or the wind pressure at every moment, and the wind speed sensor may detect the change amount of the resistance of the nichrome wire in the energized state, A pressure sensor that can detect minute pressure fluctuations can be used as the wind pressure sensor.

Further, in the above embodiments, since the heating dryer having the fan therein is used, the air flow sensor is included in the environment sensor unit, but when the dryer not having the fan is used, the air flow sensor is not necessary. In addition, if the sample is arranged so as not to be easily affected by the infrared radiation from the inner wall surface of the dryer, it is not necessary to provide the infrared sensor.

Furthermore, in the above-described embodiment, the environment sensor unit is provided for each stage in the multi-stage dryer, and the drying time is corrected for each stage, but the present invention is not limited to this. Alternatively, each stage may be further divided into a plurality of regions, and the arrangement of the environmental sensor unit and the correction of the drying time may be performed for each region, or in the one-stage dryer, each sample placement position may be appropriately set. Alternatively, the environment sensor unit may be arranged in each of the areas, and the drying time may be corrected.

Further, according to the present invention, the technique of removing the influence of the position of each sample inside the dryer by moving the sample arrangement position inside the dryer with time, and the number of rotations of the fan are appropriately changed. Does not interfere with the combination with technology.

Furthermore, in the above-mentioned embodiment, one electronic balance is described for measuring mass before and after drying, but dedicated electronic balances may be used for measuring mass before and after drying. Needless to say.

[0032]

As described above, according to the present invention,
The inside of the heating dryer for drying the sample is divided into a plurality of areas, and the temperature, the air volume or the wind speed or the wind speed is applied to each of the areas.
Since a sensor for detecting environmental factors such as the amount of radiant infrared rays is provided, and it is configured to automatically adjust the set drying time for each area based on the output of the environmental sensor,
Even if temperature unevenness or air flow unevenness exists in the dryer, the measurement result of the mass change amount of the sample is hardly affected by the position inside the dryer, and the reproducibility and reliability of the data are improved.

Further, by adopting the present invention, it is not necessary to take various hardware measures in order to make the temperature distribution in the dryer uniform, and a low-cost and highly accurate mass change amount automatic measuring device is provided. Will be obtained.

[Brief description of drawings]

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

[Explanation of symbols]

 1 Electronic Balance 2 Heat Dryer 21 Heater 23 Fan 26 Automatic Door A to C Sample Placement Rack 3 Sample Transfer Robot 4A to 4C Environmental Sensor Unit 5 Control Unit 51 Data Processing Unit 52 Storage Unit 53 Correction Coefficient Calculation Unit 54 Drying Time Calculation part 55 Clock part 6 Keyboard 7 CRT 8 Printer 10 Actuator controller

Claims (1)

[Claims] 1. A mass measuring unit for measuring the mass of a sample, a heating / drying device in which a plurality of samples can be arranged, a handling mechanism for moving the sample between them, and a heating / drying time for the sample are set. An apparatus equipped with a setting device for automatically measuring a change amount or a change rate of a sample mass before and after a heating and drying process for a set time, wherein one or a plurality of sample placement positions in the heating and drying device are provided. Each area is provided with an environment sensor including at least one of a temperature sensor, an air volume or speed or pressure sensor, and an infrared sensor, and the setting device based on the output from each environment sensor. It is equipped with a computing unit that corrects the set time by, and is configured so that the heating and drying time of the sample is automatically adjusted for each sample placement position in the area corresponding to each environmental sensor. An automatic measuring device for the amount of change in mass.