JP2651495B2 - Thermal analyzer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermal analyzer for measuring the temperature dependence of physical properties of a material.

[Summary of the Invention]

The present invention aims to change the temperature of a sample to be measured accurately in accordance with a desired temperature function. Therefore, a temperature function generator, a temperature function converter, a temperature-voltage converter, a heating furnace, a comparison furnace, The above object is achieved by performing a temperature conversion that includes a power generator and a measurement unit and corrects a temperature difference between the heating furnace and a sample placed in the measurement unit in the temperature function converter. It was made.

[Prior art] Conventionally, with respect to this type of invention, a sample having no temperature function converter or a sample temperature instead of a heating furnace temperature without the temperature function converter is input to the comparison operation circuit. And controls the power supplied to the heating furnace.

[Problems to be solved by the invention]

In the prior art described above, in the former case, it is relatively easy to control the heating furnace temperature to match a desired temperature function, but at this time, the sample temperature is always lower than the heating furnace temperature, and Since the deviation width depends on the temperature, there is a disadvantage that it is extremely difficult to make the sample temperature coincide with a desired temperature function. In the latter case, since the heating furnace is controlled using the sample temperature as a control signal, the sample temperature relatively easily matches the desired temperature function. However, the change in temperature of the heating furnace to be controlled is controlled by the control signal (sample temperature). Since a time delay occurs before the change is detected, the control is unstable and easily disturbed.

[Means for solving the problem]

The primary purpose of this invention was to eliminate the above-mentioned disadvantages, and its main components were a temperature function generator, a temperature function converter, a temperature-voltage converter, a heating furnace, a comparison operation circuit, and a proportional voltage generator. And a measuring unit.

[Action]

The operation of the above configuration is as follows. First, when a desired function form is input to the temperature function generator, the function form is such that a temperature component corresponding to the difference between the furnace temperature and the sample temperature is added to the function in the temperature function converter. Modified conversion. Since the furnace temperature is controlled by the modified function form, the temperature is controlled to be higher than the initially input function form, but at this time, the sample temperature becomes lower due to the temperature gradient than the furnace temperature, and as a result, Approximately matches the desired functional form. Further, since the temperature of the heating furnace to be controlled is directly a control signal, the time delay of the feedback loop is small, and the control is performed stably. Accordingly, the object of changing the temperature of the sample to be measured exactly according to a desired temperature function is achieved.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings shown in one embodiment. In the drawings, reference numeral 1 denotes a temperature function generator, and a temperature function converter 2 is connected to the temperature function generator 1; A temperature-voltage converter 3 is connected to 2. Reference numeral 4 denotes a heating furnace. The heating furnace 4 and the temperature-voltage converter 3 are connected to a comparison operation circuit 5, and the comparison operation circuit 5 includes a proportional power generator 6
And the proportional power generator 6 is connected to the heating furnace 4. Further, the heating furnace 4 is connected to a measuring section 7 for measuring the temperature and physical properties of a sample (not shown) to be measured.

First, when a desired temperature function form is input to the temperature function generator 1, the temperature function converter 2 compares the temperature of the heating furnace 4 with the measurement unit 7.
The temperature function form is modified in such a manner that the difference from the temperature of the sample placed in the temperature function is added to the temperature function. The corrected temperature function is sent from the temperature function converter 2 to the temperature-voltage converter 3 and converted from the temperature function into a voltage function that matches the temperature-voltage characteristics of the temperature detector used. A temperature detection signal from a temperature detector (not shown) arranged in the heating furnace 4 and the voltage function are sent to a comparison operation circuit 5 and subjected to a comparison integral / differential control operation on a signal difference. , An operation signal is sent to the proportional power generator 6, and power proportional to the operation signal is supplied from the proportional power generator 6 to the heating furnace 4 to control the temperature of the heating furnace 4. Further, heat is transmitted from the heating furnace 4 to the sample placed in the measuring section 7 by conduction, convection or radiation, and the measuring section 7 outputs a temperature and physical property value measurement signal of the sample.

The temperature conversion in the temperature function converter 2 will be described in more detail. First, a function form is given to the temperature function generator 1 so as to keep the heating furnace 4 at a constant temperature at each temperature. Is approximated by a polynomial so that heating furnace temperature = f (sample temperature). The function of the temperature function converter 2 is to apply the above-mentioned conversion f to the input value and output the result.

In this way, the function input to the temperature function generator 1 is corrected to be higher by the temperature function converter 2 in view of the temperature difference between the heating furnace and the sample, and finally the sample temperature is changed to the function type initially input. Almost match, reach the purpose.

The temperature function generator 1, the temperature function converter 2, the temperature-voltage converter 3, and the comparison operation circuit 5 can be constituted by an analog circuit or a digital circuit, but this selection limits the contents of the present invention. Of course it is not.

〔The invention's effect〕

As described above, according to the present invention, the temperature function converter is provided between the temperature function generator and the temperature-voltage converter, and the deviation between the temperature of the heating furnace to be controlled and the sample temperature is always corrected. Therefore, the sample temperature can be changed according to a desired temperature function, and the operator does not need to be aware of the difference between the heating furnace temperature and the sample temperature. Furthermore, since the temperature of the heating furnace to be controlled is directly used as a control signal, there is an effect that a time delay of the control feedback loop is small and stable control is always performed.

[Brief description of the drawings]

 The drawing is a block diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Temperature function generator 2 ... Temperature function converter 3 ... Temperature-voltage converter 4 ... Heating furnace 5 ... Comparison arithmetic circuit 6 ... Proportional power generator 7 ... Measurement part

Claims (2)

(57) [Claims] 1. A temperature function generator for generating a temperature function corresponding to a temperature using time as a variable, a heating furnace connected to the temperature function generator for changing a temperature of a sample, a temperature of the sample, and the heating of the sample. A temperature detector for detecting the temperature of the furnace, connected to the temperature function generator, to correct the temperature function based on the temperature difference between the temperature of the sample and the temperature of the heating furnace detected by the detector, A temperature function converter that outputs a signal for controlling the temperature of the heating furnace only by the previously corrected temperature function, and a measuring unit that is connected to the heating furnace and measures a physical property value of a sample to be analyzed. Thermal analyzer. 2. The thermal analysis apparatus according to claim 1, wherein the temperature difference between the heating furnace and the sample is obtained by maintaining the heating furnace at a constant temperature at each temperature, and operating the temperature function converter. apparatus.