JPH071243B2 - Thermal analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] This invention is directed to differential thermal analysis (DTA), differential scanning calorimetry (DTA).
SC), thermogravimetric measurement (TG), thermomechanical analysis (TMA), etc.

[Conventional technology]

In this type of thermal analysis, the sample is placed in a furnace,
The temperature of the furnace is controlled according to a certain program to measure the thermal properties of the sample. In this way, during the measurement, the temperature of the heating furnace is strictly controlled, but after the measurement is completed, the temperature of the heating furnace is lowered by allowing it to cool naturally or by forced cooling with a cooling fan. Then, whether or not the temperature of the heating furnace has fallen to a temperature at which the next measurement can be performed is conventionally judged by touching the outer wall surface of the heating furnace with that feeling.

[Problems to be solved by the invention]

However, in the method that relies on the tactile sensation of the experimenter as in the past, even if the temperature of the heating furnace has dropped below the required temperature, the heating furnace is left for a longer time than necessary before the next measurement is performed. It is easy to leave things as they are, and the experimental efficiency is poor. Alternatively, touch the heating furnace more frequently than necessary to check the cooling status,
Very annoying.

The present invention has been made to solve the above-mentioned conventional problems, and after the measurement is completed, the heating furnace is forcibly cooled, and the following is promptly performed without spending more time than necessary for the cooling. It is a technical object to provide a thermal analysis apparatus that can start measurement and can know the timing without needing to obtain it.

[Means for solving problems]

The present invention, as a technical means for achieving the above object, the reaction tube in which the sample is housed is equipped with a heating furnace,
In a thermal analyzer for measuring the thermal properties of the sample, the heating furnace is lifted upward and removed from the reaction tube, supported by a support member integrally provided in the heating furnace, and a column is supported. After being rotated about a rotation center, it is configured to be lowered and set at a cooling position, and is arranged below the cooling position and blows air to the heating furnace to cool the heating furnace. A fan, a temperature detecting means for detecting that the heating furnace is cooled and the temperature of the heating furnace is lowered to a predetermined temperature or less, and the temperature detecting means detects that the temperature of the heating furnace is lowered to a predetermined temperature or lower. A thermal analysis device is configured to have a circuit for notifying that at the time and for stopping the operation of the cooling fan.

[Action]

Since the present invention has the configuration as described above, in the thermal analysis device according to the present invention, after the measurement is completed, the heating furnace is removed from the reaction tube and set at the cooling position, and at the cooling position, If the heating furnace is forcibly cooled by the cooling fan and the temperature of the heating furnace drops to the predetermined temperature required for the next measurement, the temperature detection means detects that and notifies the outside, and the automatic As a result, the cooling fan is stopped, so that the next measurement work can be promptly performed without any human intervention.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, which is a side view showing a schematic configuration when the present invention is applied to a differential thermal analysis apparatus, and FIG. 2 is a movement of a heating furnace of the apparatus. It is a top view for explaining a mechanism. In the figure, heating furnace 10
Moves reciprocally between a measurement position A shown by a two-dot chain line and a cooling position B shown by a solid line. At the measurement position A, a reaction tube 12 in which a sample and a standard substance are housed is arranged. The reaction tube 12 is covered with a heating furnace 10, and a differential thermal analysis is performed in that state (for analysis). Details are omitted because they are not related to the gist of the present invention). When the measurement is completed, the heating furnace 10 is lifted up and removed from the reaction tube 12, supported by the support arm portion 14 integrally provided in the heating furnace 10, and rotated 90 ° around the support column 16 as a rotation center. After being moved
It is lowered and set in the cooling position B. This movement may be performed manually or automatically. At the cooling position B, a blower port (not shown) is opened on the upper surface of the base 18 and directly below the heating furnace 10.
A cooling fan 20 and a drive motor 22 thereof are fixedly installed below the cooling fan 20. Further, a detection end 28 of a thermocouple 26 is arranged at the upper end opening portion of the cylindrical hole 24 of the heating furnace 10. Then, when the heating furnace 10 is set to the cooling position B, the switch 30 is turned on manually or automatically so that the drive motor 22 is driven and the cooling fan 20 is rotated to rotate the cylinder of the heating furnace 10. The air is blown into the holes 24, and the forced cooling of the heating furnace 10 is started. When cooling of the heating furnace 10 is started, the temperature of the wind at the outlet of the tube hole 24 of the heating furnace 10 is measured by the thermocouple 26, and the signal from the thermocouple 26 is amplified by the amplifier 32. This amplified signal is compared with a reference signal corresponding to the temperature preset by the temperature setting unit 34 by the comparator 36 as the temperature at which the next measurement can be performed. Then, a circuit is designed so that the relay 38 is operated when the temperature measured by the thermocouple 26 once exceeds the set temperature and then becomes below the set temperature again. When the temperature of the heating furnace 10 decreases and the relay 38 operates, the relay contact 40 switches from the position shown by the solid line to the position shown by the broken line, the power supply to the drive motor 22 stops, and the rotation of the cooling fan 20 stops. To do. At the same time, the relay contact 42 switches from the position shown by the solid line to the position shown by the broken line, and sends a signal to the external circuit. This signal informs the experimenter that the temperature of the heating furnace has dropped to the temperature required for the next measurement by, for example, sounding a buzzer or blinking a lamp. Then, the heating furnace 10 is returned to the original measurement position again, and the next measurement is performed.

Next, FIG. 3 is a diagram showing another embodiment of the present invention.
In this figure, elements designated by the same reference numerals as in FIG. 1 are the same members having the same function. In the embodiment shown in FIG. 3, the cooling fan 20 'and the drive motor 22' blow air to the outer surface of the heating furnace 10 to forcibly cool the heating furnace 10. Bimetal 44 (or shape memory alloy, etc.) into tube hole 24 of heating furnace 10.
, And replace this bimetal 44 as a thermocouple,
The time when the temperature in the heating furnace 10 drops below a predetermined temperature is detected. That is, the contact 46 of the bimetal 44 is closed while the temperature inside the heating furnace 10 is high, and in this state, the relay 38 does not operate and the heating furnace 10 is cooled, so that the temperature inside the heating furnace 10 increases. Bimetal 44 contacts falling 46
The relay 38 is configured to operate when is opened.

The present invention is configured as described above, but the scope of the present invention is not limited by the above description and the contents of the drawings, and various modifications can be included within the scope not departing from the claims. For example, in the above-described embodiment, the differential thermal analysis device was described as an example of the thermal analysis device.
The present invention can be similarly applied to other thermal analysis devices such as C, TG and TMA. The thermocouple temperature measurement circuit may be the circuit of the thermal analysis device itself or may be provided separately therefrom. Furthermore, any means can be used as the temperature detecting means as long as it can detect the temperature, and it can be attached to the heating furnace from the beginning.

〔The invention's effect〕

Since the present invention is configured and operates as described above, according to the thermal analysis device of the present invention, the heating furnace is forcibly cooled after the measurement is completed, and the temperature of the heating furnace can be measured next time. Since it is possible to accurately know that the temperature has dropped to the specified temperature without human intervention, it is possible to quickly proceed to the next measurement work without spending more time than necessary for cooling, which is efficient and efficient. Yes, and economically,
It eliminates the annoyance of the past. Then, by utilizing the present invention, it becomes possible to automate a series of thermal analysis operations.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, which is a side view showing a schematic configuration when the present invention is applied to a differential thermal analysis apparatus, and FIG. 2 is a moving mechanism of a heating furnace of the apparatus. FIG. 3 is a plan view for explaining FIG. 3 and FIG. 3 is a view showing another embodiment of the present invention. 10 …… heating furnace, 20 …… cooling fan, 26 …… thermocouple, 44
……bimetal.

Claims (1)

[Claims] 1. In a thermal analyzer for measuring a thermal property of a sample by mounting a heating furnace on a reaction tube containing a sample therein, the heating furnace is lifted upward and removed from the reaction tube. It is configured to be supported by a support member integrally provided in the heating furnace, to be rotated around a support post, and then to be lowered and set to a cooling position. A cooling fan that is disposed below the fan and blows air to the heating furnace to cool the heating furnace; and a temperature detecting unit that detects that the heating furnace is cooled and the heating furnace temperature drops below a predetermined temperature. And a circuit for notifying the fact that the temperature of the heating furnace is lowered to a predetermined temperature or lower by the temperature detecting means and for stopping the operation of the cooling fan. Analytical equipment .