JPS61112927A - Apparatus for analyzing heat weight - Google Patents

Abstract

PURPOSE:To remove the noise containing in measured data and the differentiated data of the measured data, by replacing the differentiation circuit in a heat wt. analytical apparatus and the RC filter contained therein with a differential operation circuit and a digital filter part. CONSTITUTION:A data processing part 14 processes the digital data from an A/D converter 13 and has a measured data input part 16 for inputting time data, temp. data and wt. data from a time differentiating timer 15 and A/D converters 12, 13 and temporarily storing measured data, a differential operation part 17 for operating differentiation from the measured data or the data after the removal of noise according to a differential method and a digital filter part 18 for removing the noise of the measured data or the differentiated data obtained by differential operation. A data output part 19 outputs time data, temp. data, wt. data, wt. data from which noise was removed, differentiated data and the differentiated data from which the noise was removed in various combinations.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermogravimetric analysis device for detecting temperature changes and weight changes of materials, and particularly to a device for removing noise contained in detected weight data. .

[Conventional technology]

Figure 3 is a configuration diagram of a conventional thermogravimetric analyzer (CI)
(:t) is the sample pan on which the sample is placed, which together with the sample forms the sample part; (3) is the weight pan on which the weight is placed to balance the sample part for measurement; The parts that together form the weight part are: (ri) is the beam for balancing the sample part and the weight part, (3) is the beam support part that supports the beam (da), and (6) is the beam support part that supports the movement of the beam (da). A photoelectric conversion element that converts optical information detected by light into electrical information, (7) a temperature detection section that detects the temperature of the sample section, and (ff) a weight change detection section that detects changes in the weight of the sample section. , (9) is a differentiating circuit that differentiates the signal obtained by the weight change detection section (A'), (/θ) is an RC filter inserted in the plate circuit at ℃, (11) is temperature data, weight data, This is a recorder that records differential data, etc.

A conventional thermogravimetric analyzer is configured as described above. For example, when the sample part is heated by the heater (1) at a constant rate of temperature increase, when the mass of the sample on the sample plate (2) changes, the beam support part 0
) The beam (ri) supported by the beam (ri) is tilted, so this movement is detected with light or the like and used as weight data.The differential circuit (ri) outputs the differential data, and the temperature data obtained by the temperature detection section (7) is obtained. At the same time, three types of data are recorded on the recorder (ll).

[Problem that the invention seeks to solve]

However, as mentioned above, conventional thermogravimetric analyzers detect minute changes in the beam (4') by maintaining balance and use them as recorded signals. ) is further emphasized in the differential data, so the RC filter (io) installed in the differential circuit may not remove it, or if the filter is strengthened to remove it, the signal will be significantly affected. This will cause a delay.

For this reason, it is no longer possible to obtain highly reliable differential data, which poses a problem in that it poses a problem when performing various data analysis, especially reaction kinetic analysis.

An object of the present invention is to provide a thermogravimetric analyzer that removes noise contained in measurement data and differential data of measurement data.

[Means for solving problems]

In the thermogravimetric analyzer according to the present invention, the differential circuit and the RC filter included therein in the conventional thermogravimetric analyzer are replaced with a differential calculation section and a digital filter section. The differential calculation section performs time or temperature differentiation on the input weight data, and the filter section performs filter processing on the input weight data.

It is preferable to use a Fourier digital filter in the filter section.

[Effect]

According to the technical means of the present invention, the measured weight data is filtered and then subjected to differential calculation processing, or the unprocessed measured weight data is processed through differential calculation processing and then filtered. Data is output along with the data.

〔Example〕

FIG. 2 is a block diagram showing an embodiment of the present invention, and the reference numeral (
1) to Cg) indicate parts that are completely the same as the above-mentioned conventional device. (ll) and (13) are A/D converters that convert analog data into digital signals such as signals detected by the temperature detection section (ri) and weight change detection section (g), respectively;
The A/D converter (13) is a data processing unit that processes digital data from the A/D converter (13). The measurement data input section (1) inputs data and weight data and temporarily stores the measurement data, and the differential calculation section (1) calculates the differential from the measurement data or the data after noise removal using the difference method etc.
? ), it has a digital filter section (/r) that removes noise from the measured data or the differential data obtained by the differential calculation section (17). Also, (/de) is a data output section that can output time data, temperature data, weight data, noise-removed weight (da) data, differential data, noise-removed differential data, etc. in various combinations.

In the thermogravimetric analyzer configured as above, the measurement data input section (1g) is connected to the digital filter section (1g).
16) Noise removal and differential calculation unit for measurement data from (
It is possible to remove noise from differential data from /7), 0 weight machine data, and temperature differential data). Therefore, the measurer can obtain data that is not affected by noise, and since the obtained data is digital data, it can be processed directly on a computer, making it suitable for various data analyses, especially reaction kinetic analyzes that handle differential data. Get reliable results.

In addition, the processing procedure in the digital filter section (tB) may be any method as long as it has the function of removing noise without imparting distortion, but for example, the data is converted into the frequency domain by Fourier transform (FFT) processing, and its high frequency components are removed. After - FF that inversely transforms into time series data by inverse FFT processing
Analog R for processing such as T digital filter
There is no data delay that occurs with C filters, and noise can be removed with relatively little distortion.

As can be seen from Figures 1 and 2, the data sent from the data processing unit (/l) to the data output unit (iq) is output from the measured data input unit (16) without performing any filter processing or differential calculation. Temperature data and weight data sent directly to section (19), ■Measurement data input section (/A
) is sent to the digital filter section (tg) and subjected to filter processing, then subjected to differential calculation in the differential calculation section (17) and sent to the data output section (19), and ■Measurement data input section (16) After being sent to the differential calculation unit (17) and subjected to differential calculation, it is sent to the digital filter unit (7g).
There are three types of data: weight data, which is sent to the computer, filtered, and sent to the data output section (19).
is essentially unchanged. In addition, it is also possible to output data only for differential calculation or filter processing.

Further, as shown in FIG. 3, when performing filter processing on an asynchronous function such as weight data, it is sufficient to have a function of providing a window function.

In Fig. DA, an FF'T digital filter is adopted for the digital filter section (1g), and the weight data, differential calculation section (1g) is used.
For comparison, the differential data calculated in step 7) and the result of outputting the differential data after removing noise in the digital filter section (ttB to the data output section (/9)) as shown in Fig. 5. The experimental results are shown showing differential data from which noise has been removed using an RC filter.The temperature change on the horizontal axis corresponds to the time change.In Figure 1, the differential data from which noise has been removed using an FFT digital filter is It has been shown that only noise is removed without causing any data delay due to smoothing as in conventional analog RC filters.

Furthermore, in the present invention, the measurement data inputted to the measurement data input section (16K) can be stored on a magnetic tape, disk, etc., and then retrieved as needed.

In addition, in the above explanation, the present invention is used to remove noise from measurement data,
Although the case where the present invention is used for computing differential data and removing noise from differential data has been described, the present invention is not limited to this, and it goes without saying that it can be similarly utilized for other devices.

〔Effect of the invention〕

As explained above, the present invention has a simple structure in which a differential operation section and a digital filter section are attached to a part of the device, and it is possible to remove noise that could not be removed with conventional analog RC filters, and it is possible to perform various data analysis. ,
This method has the advantage that highly reliable results can be obtained even in reaction kinetic analysis, which is particularly susceptible to the influence of noise.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing an embodiment of the algorithm of the data processing section of the present invention, and FIG. 3 is an example of the algorithm of the digital filter section of the present invention. Flowcharts and diagrams illustrating the embodiments are shown in FIG.
A graph showing the experimental results when an FT digital filter is used. Figure S is a configuration diagram of a conventional thermogravimetric analyzer.
It is. In the figure, (/6) is the measurement data input section, (/7) is the differential calculation section, (tg) is the digital filter section, (19)
is the data output section. Note that the same reference numerals in each figure indicate the same or corresponding parts. 2 sheep figures, 3 leather figures, 4 rod figures! Degree C)

Claims (2)

[Claims] (1) a measurement data input section that takes in detected temperature data and weight data; a digital filter section that is connected to the data input section and filters the input weight data;
a differential calculation unit that is connected to the data input unit and the filter unit and performs time or temperature differential calculations on the input weight data; and a differential calculation unit that performs time or temperature differential calculations on the input weight data; A thermogravimetric analyzer comprising: a data output unit that outputs the temperature data and weight data. (2) The digital filter section is a patented Fourier transform digital filter that transforms input weight data into a frequency domain through Fourier transform processing, removes high frequency components thereof, and then transforms it back into time series data through inverse Fourier transform processing. A thermogravimetric analyzer according to claim 1.