JPH0349067B2 - - Google Patents
Info
- Publication number
- JPH0349067B2 JPH0349067B2 JP4240183A JP4240183A JPH0349067B2 JP H0349067 B2 JPH0349067 B2 JP H0349067B2 JP 4240183 A JP4240183 A JP 4240183A JP 4240183 A JP4240183 A JP 4240183A JP H0349067 B2 JPH0349067 B2 JP H0349067B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature difference
- difference signal
- circuit
- amplifier
- sample
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000001514 detection method Methods 0.000 claims description 13
- 238000005259 measurement Methods 0.000 claims description 11
- 230000002265 prevention Effects 0.000 claims description 2
- 238000010586 diagram Methods 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 5
- 230000003321 amplification Effects 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000002076 thermal analysis method Methods 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity
- G01N25/48—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity on solution, sorption, or a chemical reaction not involving combustion or catalytic oxidation
- G01N25/4806—Details not adapted to a particular type of sample
- G01N25/4813—Details not adapted to a particular type of sample concerning the measuring means
Description
【発明の詳細な説明】
本発明は、標準試料及び試料を加熱炉で同時に
加熱して昇温し、両者間の温度差信号を利用して
該試料の熱分析を行なう走査型示差熱量計におけ
る温度差信号増幅器の飽和防止回路に関する。Detailed Description of the Invention The present invention relates to a scanning differential calorimeter that heats a standard sample and a sample simultaneously in a heating furnace to raise their temperature, and performs thermal analysis of the sample using a temperature difference signal between the two. The present invention relates to a saturation prevention circuit for a temperature difference signal amplifier.
従来、かかる走査型示差熱量計において、試料
及び標準試料として熱容量の大きいものを用いた
場合、両者の熱容量を合せることが困難であるた
め、測定を開始すべく加熱炉を第１図のに示す
ように昇温し、試料及び標準試料を加熱した時、
両者間にはに示すように温度差（破線は温度差
の零線）が生ずる。この熱容量の差による温度差
信号は試料の反応熱による温度差信号に較べて
非常に大きいから、熱容量の差による温度差信号
を高感度の増幅器に入力すると、その増幅特性は
飽和してしまい、試料の熱介析が正確にできな
い。そこで第２図示のようにポテンシヨメータａ
を用い、その摺動端子を温度差検出回路ｂと直列
接続して該回路ｂが出力する温度差信号から熱容
量の差による温度差信号に対応するポテンシヨメ
ータａの出力電圧を差引いて後増幅器ｃに入力す
るように構成している。しかし、前記熱容量の差
による温度差信号は試料及び標準試料等を変える
毎に異なるため、測定開始より所定時間後に増幅
器の出力状態を見てポテンシヨメータａの出力電
圧を設定する必要があり、手数がかかる不都合が
存する。 Conventionally, in such a scanning differential calorimeter, when samples and standard samples with large heat capacities are used, it is difficult to match the heat capacities of the two, so in order to start measurement, the heating furnace is set as shown in Figure 1. When the temperature is raised and the sample and standard sample are heated,
A temperature difference occurs between the two (the broken line is the zero line of the temperature difference) as shown in . The temperature difference signal due to this difference in heat capacity is much larger than the temperature difference signal due to the reaction heat of the sample, so if the temperature difference signal due to the difference in heat capacity is input to a highly sensitive amplifier, its amplification characteristics will be saturated. Thermal intervention of the sample cannot be performed accurately. Therefore, as shown in the second diagram, use the potentiometer a.
is used, its sliding terminal is connected in series with temperature difference detection circuit b, and the output voltage of potentiometer a corresponding to the temperature difference signal due to the difference in heat capacity is subtracted from the temperature difference signal outputted by circuit b. The configuration is such that it is input to c. However, since the temperature difference signal due to the difference in heat capacity differs each time the sample and standard sample are changed, it is necessary to set the output voltage of potentiometer a by checking the output state of the amplifier after a predetermined time from the start of measurement. There is an inconvenience that requires a lot of effort.
本発明は、かかる不都合を無くすことをその目
的としたもので、標準試料及び試料を加熱して昇
温し、両者間の温度差信号を温度差検出回路で得
るようにした走査型示差熱量計において、該温度
差検出回路から出力した前記温度差信号を増幅す
る増幅器と、該増幅器に接続され、測定開始より
前記温度差信号が一定値になり且つ試料が反応す
る前までの時間経過時の温度差信号の記憶回路と
を備え、前記増幅器の入力回路において前記温度
差信号から前記記憶回路の出力信号を差引くよう
にしたことを特徴とする。 The present invention aims to eliminate such inconveniences, and is a scanning differential calorimeter in which a standard sample and a sample are heated to raise their temperature, and a temperature difference signal between the two is obtained by a temperature difference detection circuit. an amplifier that amplifies the temperature difference signal output from the temperature difference detection circuit; and a storage circuit for a temperature difference signal, and an output signal of the storage circuit is subtracted from the temperature difference signal in an input circuit of the amplifier.
第３図は、本発明の１実施例の回路図を示す。
同図において、１は試料及び標準試料に各設けた
熱電対を互に逆極性に接続し、両者間の温度差信
号を出力する温度差検出回路で、この回路１は差
動増幅器２の（＋）入力端子に接続され、この出
力から増幅された温度差信号を得るようにしてお
り、この回路は従来の走査型示差熱量計の回路と
異ならない。 FIG. 3 shows a circuit diagram of one embodiment of the invention.
In the figure, reference numeral 1 denotes a temperature difference detection circuit that connects thermocouples provided on the sample and standard sample with opposite polarities and outputs a temperature difference signal between the two. +) input terminal, and an amplified temperature difference signal is obtained from this output, and this circuit is no different from that of a conventional scanning differential calorimeter.
本発明によれば、前記回路に測定開始より前記
温度差信号が一定値になり且つ試料が反応する前
までの時間経過時の温度差信号の記憶回路３を接
続し、該回路３の出力信号を前記温度差検出回路
１の出力信号から差引くようにしたもので、以下
この構成を更に詳細に説明する。 According to the present invention, a storage circuit 3 is connected to the circuit for storing the temperature difference signal when the time elapses from the start of measurement until the temperature difference signal becomes a constant value and before the sample reacts, and the output signal of the circuit 3 is connected to the circuit. is subtracted from the output signal of the temperature difference detection circuit 1, and this configuration will be explained in more detail below.
該記憶回路３は、アナログーデイジタルコンバ
ータ４（以下Ａ−Ｄコンバータという）と、該Ａ
−Ｄコンバータ４にスイツチ５を介して接続され
たメモリ６と、その出力回路に接続されたデイジ
タル−アナログコンバータ７（以下Ｄ−Ａコンバ
ータという）と、前記増幅器２の増幅率Ａの逆数
の減衰率を有するアツテネータ８と前記スイツチ
５及び出力回路に介入されたスイツチ９を作動す
るタイヤ１０とから成り、該アツテネータ８の出
力は差動増幅器２の（−）入力端子に接続した。 The storage circuit 3 includes an analog-to-digital converter 4 (hereinafter referred to as an A-D converter) and an analog-to-digital converter 4 (hereinafter referred to as an A-D converter);
- a memory 6 connected to the D converter 4 via a switch 5; a digital-to-analog converter 7 (hereinafter referred to as a D-A converter) connected to its output circuit; and attenuation of the reciprocal of the amplification factor A of the amplifier 2. The output of the attenuator 8 is connected to the (-) input terminal of the differential amplifier 2.
加熱炉で試料及び標準試料を加熱して昇温さ
せ、測定を開始した時、前記温度差検出回路１の
出力信号は、第４図示のＡのように上昇し、所定
時間ｔ後一定値になる。前記タイマ１０は、測定
開始より例えば該所定時間ｔを設定時間とし、該
設定時間に前記スイツチ５を短時間作動するパル
ス信号（第４図Ｂ）と、該設定時間から前記スイ
ツチ９を継続して閉成する作動信号（第４図Ｃ）
とを出力するものである。 When the sample and the standard sample are heated in a heating furnace to raise their temperature and measurement is started, the output signal of the temperature difference detection circuit 1 rises as indicated by A in Figure 4, and after a predetermined time t reaches a constant value. Become. The timer 10 sets, for example, the predetermined time t from the start of measurement as a set time, and sends a pulse signal (FIG. 4B) that operates the switch 5 for a short time at the set time, and continues to operate the switch 9 from the set time. Activation signal to close (Fig. 4C)
This outputs the following.
次にこの実施例の作動を説明する。 Next, the operation of this embodiment will be explained.
加熱炉を昇温させ、試料の測定を開始すると、
タイマ１０は作動を開始し、温度差検出回路１か
ら第４図のＡに示すような温度差信号が出力し、
この信号は差動増幅器２で増幅されてＡ−Ｄコン
バータ４に入力する。設定時間ｔ経過するとスイ
ツチ５が短時間閉じる（第４図Ｂ）ので、設定時
間ｔにおける温度差信号がメモリ６に入力し記憶
される。かくしてこのメモリ６の出力は、Ｄ−Ａ
コンバータ７によりアナログ信号に変換され、ア
ツテネータ８を経て差動増幅器２の（−）入力端
子に入力する。この結果、設定時間経過時の温度
差信号はアツテネータ８の出力信号で相殺され、
差動増幅器２の出力信号は零になる（第４図Ｄ）。
したがつて設定時間後に試料が反応し、その反応
熱により標準試料間に温度差が生じた時には、そ
の微細な温度差信号は差動増幅器２により高感度
に増幅されて、スイツチ９を経て出力される。 When the temperature of the heating furnace is raised and the measurement of the sample is started,
The timer 10 starts operating, and the temperature difference detection circuit 1 outputs a temperature difference signal as shown in A in FIG.
This signal is amplified by the differential amplifier 2 and input to the AD converter 4. When the set time t has elapsed, the switch 5 closes for a short time (FIG. 4B), so that the temperature difference signal at the set time t is input to the memory 6 and stored. Thus, the output of this memory 6 is D-A
The signal is converted into an analog signal by the converter 7, and is input to the (-) input terminal of the differential amplifier 2 via the attenuator 8. As a result, the temperature difference signal after the set time has elapsed is canceled out by the output signal of attenuator 8,
The output signal of the differential amplifier 2 becomes zero (FIG. 4D).
Therefore, when the sample reacts after the set time and a temperature difference occurs between the standard samples due to the reaction heat, the minute temperature difference signal is amplified with high sensitivity by the differential amplifier 2 and output via the switch 9. be done.
第５図は本発明の他の実施例の回路を示す。こ
の回路において、測定開始より前記温度差信号が
一定値になり且つ試料が反応する前までの時間経
過時の温度差信号の記憶回路３は、前記温度検出
回路１の出力信万を増幅する増幅器２の出力に接
続された増幅器１１と、タイマ１０と、該タイマ
１０により測定の開始から例えば第４図に示すよ
うな所定時間ｔ経過まで閉成されるスイツチ１２
と、増幅器１１及びスイツチ１２を経て入力する
信号により付勢されるサーボモータ１３と、該サ
ーボモータ１３により駆動されるポテンシヨメー
タ１４とから成り、該ポテンシヨメータ１４は、
その出力と温度差検出回路１の出力とが逆極性に
なるように該温度差検出回路１に接続した。 FIG. 5 shows a circuit of another embodiment of the invention. In this circuit, a storage circuit 3 for storing a temperature difference signal during a time elapsed from the start of measurement until the temperature difference signal becomes a constant value and before the sample reacts is an amplifier that amplifies the output signal of the temperature detection circuit 1. an amplifier 11 connected to the output of 2, a timer 10, and a switch 12 that is closed by the timer 10 from the start of measurement until a predetermined time t has elapsed as shown in FIG.
, a servo motor 13 energized by a signal input via an amplifier 11 and a switch 12, and a potentiometer 14 driven by the servo motor 13.
It was connected to the temperature difference detection circuit 1 so that its output and the output of the temperature difference detection circuit 1 had opposite polarities.
かくして、加熱炉で試料及び標準試料を加熱し
て昇温させ、測定を開始した時、第４図Ａに示す
ような温度差信号が設定時間ｔまで増幅器２及び
増幅器１１で増幅されてサーボモータ１３に加わ
りポテンシヨメータ１４の摺動子を作動させるか
ら、設定時間経過時の温度差信号はポテンシヨメ
ータ１４の出力信号によつて相殺される。設定時
間経過後、スイツチ１２は開成され、ポテンシヨ
メータ１４の摺動子はその位置に保持されるか
ら、その後試料が反応し、その反応熱により標準
試料間に温度差が生じた時には、その微細な温度
差信号は増幅器２で高感時に増幅されて出力され
る。 Thus, when the sample and standard sample are heated in the heating furnace to raise their temperature and measurement is started, a temperature difference signal as shown in FIG. 13 and actuates the slider of potentiometer 14, the temperature difference signal after the set time has elapsed is canceled out by the output signal of potentiometer 14. After the set time has elapsed, the switch 12 is opened and the slider of the potentiometer 14 is held in that position, so that when the sample reacts and a temperature difference occurs between the standard samples due to the reaction heat, the switch 12 is opened and the slider of the potentiometer 14 is held in that position. The minute temperature difference signal is amplified by the amplifier 2 and output when the sensitivity is high.
このように本発明によるときは、走査型示差熱
量計において、測定開始より前記温度差信号が一
定値になり且つ試料が反応する前までの時間経過
時の温度差信号の記憶回路を設け、温度差信号の
増幅器の入力回路において該温度差信号から前記
記憶回路の出力信号を差引くようにしたから、試
料と標準試料との間に熱容量に差があつても、該
熱容量の差による温度差信号は打消され、そのた
め増幅器の増幅特性は該温度差信号により飽和す
るようなことがなく、試料の反応により試料と標
準試料間に温度差が生じた時、その微細な温度差
信号を増幅器により高感度に増幅することがで
き、試料の熱分析を正確に行なうことができる効
果を有す。 As described above, according to the present invention, a scanning differential calorimeter is provided with a storage circuit for storing temperature difference signals over time from the start of measurement until the temperature difference signal becomes a constant value and before the sample reacts. Since the output signal of the storage circuit is subtracted from the temperature difference signal in the input circuit of the difference signal amplifier, even if there is a difference in heat capacity between the sample and the standard sample, the temperature difference due to the difference in heat capacity is The signals are canceled, so the amplification characteristics of the amplifier will not be saturated by the temperature difference signal, and when a temperature difference occurs between the sample and the standard sample due to the reaction of the sample, the minute temperature difference signal can be used by the amplifier. It has the effect of being able to amplify with high sensitivity and accurately performing thermal analysis of a sample.
第１図は走査型示差熱量計の作用説明図、第２
図は従来のこの種熱量計の増幅部の回路図、第３
図は本発明の１実施例の回路図、第４図は第３図
示の回路の作動説明図、第５図は本発明の他の実
施例の回路図を示す。
１……温度差検出回路、２……増幅器、３……
記憶回路。
Figure 1 is an explanatory diagram of the operation of a scanning differential calorimeter, Figure 2
The figure is a circuit diagram of the amplifier section of a conventional calorimeter of this type.
This figure shows a circuit diagram of one embodiment of the present invention, FIG. 4 is an explanatory diagram of the operation of the circuit shown in FIG. 3, and FIG. 5 is a circuit diagram of another embodiment of the present invention. 1...Temperature difference detection circuit, 2...Amplifier, 3...
memory circuit.
Claims (1)
の温度差信号を温度差検出回路で得るようにした
走査型示差熱量計において、該温度差検出回路か
ら出力した前記温度差信号を増幅する増幅器と、
該増幅器に接続され、測定開始より前記温度差信
号が一定値になり且つ試料が反応する前までの時
間経過時の温度差信号の記憶回路とを備え、前記
増幅器の入力回路において前記温度差信号から前
記記憶回路の出力信号を差引くようにしたことを
特徴とする走査型示差熱量計における増幅器の飽
和防止回路。1. In a scanning differential calorimeter in which a standard sample and a sample are heated to raise their temperature and a temperature difference signal between the two is obtained by a temperature difference detection circuit, the temperature difference signal output from the temperature difference detection circuit is amplified. an amplifier to
a storage circuit connected to the amplifier and storing a temperature difference signal as time elapses from the start of measurement until the temperature difference signal becomes a constant value and before the sample reacts, and the input circuit of the amplifier stores the temperature difference signal. 1. A saturation prevention circuit for an amplifier in a scanning differential calorimeter, characterized in that the output signal of the storage circuit is subtracted from the output signal of the storage circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4240183A JPS59168349A (en) | 1983-03-16 | 1983-03-16 | Saturation preventive circuit of amplifier in scanning-type differential calorimeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4240183A JPS59168349A (en) | 1983-03-16 | 1983-03-16 | Saturation preventive circuit of amplifier in scanning-type differential calorimeter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59168349A JPS59168349A (en) | 1984-09-22 |
| JPH0349067B2 true JPH0349067B2 (en) | 1991-07-26 |
Family
ID=12635043
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4240183A Granted JPS59168349A (en) | 1983-03-16 | 1983-03-16 | Saturation preventive circuit of amplifier in scanning-type differential calorimeter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59168349A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60100039A (en) * | 1983-11-07 | 1985-06-03 | Rigaku Keisoku Kk | Zero adjustor for automatically recording heat analysis |
| US5229612B1 (en) | 1990-08-01 | 1998-04-14 | Exergen Corp | Radiation detector with remote temperature reference |
-
1983
- 1983-03-16 JP JP4240183A patent/JPS59168349A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59168349A (en) | 1984-09-22 |
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