JPH059949B2 - - Google Patents
Info
- Publication number
- JPH059949B2 JPH059949B2 JP57168578A JP16857882A JPH059949B2 JP H059949 B2 JPH059949 B2 JP H059949B2 JP 57168578 A JP57168578 A JP 57168578A JP 16857882 A JP16857882 A JP 16857882A JP H059949 B2 JPH059949 B2 JP H059949B2
- Authority
- JP
- Japan
- Prior art keywords
- sio
- glass
- thermocouple
- temperature
- chromel
- 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 - Lifetime
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K1/00—Details of thermometers not specially adapted for particular types of thermometer
- G01K1/08—Protective devices, e.g. casings
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Temperature Or Quantity Of Heat (AREA)
Description
〔発明の技術分野〕
本発明は熱電対に係り、特に温度検出端部の改
良に関する。
〔発明の技術的背景とその問題点〕
一般に使用されている熱電対は、その温度検出
部を測定雰囲気に直接露呈される構造を採用して
いるものが多い。熱電対の材料としては、クロメ
ル−アルメル、クロメル−コンスタンタンまた
は、鉄−コンスタンタンなどが挙げられるが、こ
の種の熱電対では測定雰囲気の状態に起因して、
温度検出端部が酸化され、起電力の変化及び接合
部の破壊を生じる恐れがある。
そこで本発明者らは温度検出部をガラスで被覆
することによりこの問題を解決することを考え
た。しかし、この種の熱電対では、高温領域での
使用や急激な温度変化中での使用に耐えられない
場合があり、これを更に解決することが望まれ
た。
〔発明の目的〕
本発明の熱電対は、高温領域や急激な温度変化
中での使用を目的とし、
(1) 耐熱性が比較的良好でかつ
(2) 耐酸化性を有する
熱電耐を提供することにある。
〔発明の概要〕
本発明に係る熱電対は、クロメル−アルメル、
クロメル−コンスタンタンまたは、鉄−コンスタ
ンタンから選ばれる材料からなる熱電対であつ
て、B2O3−PbO−ZnO系、Na2O−Al2O3−SiO2
系、MgO−Al2O3−SiO2系、Li2O−Al2O3−SiO2
系、Na2O−CaO−MgO−SiO2系または、ZnO−
B2O3−SiO2系から選ばれ、かつ5.0×10-6／deg
〜40×10-6／degの範囲の熱膨張係数、600℃以上
の軟化点を有する厚さ0.01mm〜２mmの結晶化ガラ
スで被覆された検出端部を有することを特徴とす
るものである検出端部の耐酸化性を改善する為に
本発明ではガラスで検出端部を被覆する。これに
より耐酸化性は飛躍的に向上する。又、検出端部
は比較的複雑な形状をしている為、加工が容易な
ガラスは、その被覆に適している。しかし、ガラ
スによつては耐熱性の点で不十分となる場合を生
ずる。
そこで耐熱性を兼ね備える為にガラスを調べ
た。その結果、5.0×10-6／deg〜40×10-6／deg
の範囲の熱膨張係数を有し、600℃以上の軟化点
を有するガラスを用いることにより、前記の要求
を満たすことが分つた。
これは、ガラスの熱膨張係数が約5.0×10-6／
deg〜約40×10-6／degの範囲に有ると、比較的
金属の係数に近似し、熱衝撃によるガラス層の剥
離が生じにくく、耐熱性の改善が図れる為であ
り、又、ガラスの最高使用温度は軟化点で決りこ
の温度以下で使用されるがガラスの軟化点が約
600℃以上であると、その使用領域が板ガラスよ
り高温側へ拡大され、耐熱性の改善が図れる為で
ある。
この種のガラスとしては、結晶化ガラスがあ
る。
以上、耐熱性及び耐酸化性を兼ねそなえる熱電
耐について述べたが、更に速い熱応答性を求めら
れる場合もある。
そこで熱伝導性をも兼ね備える方法として次の
方法が考えられる。
それは、被覆ガラスの厚さを薄くすることであ
る。そのことにより、熱伝導性を向上させること
が可能である。しかし、あまり薄すぎると、機械
的強度が低下し、ガラスが破壊してしまう。
本発明では、これらの相反する要求について検
討の結果、ガラスの厚さの調整によりこれらの要
求を満たすことが分つた。
すなわち、被覆するガラスの厚さを約0.01mm〜
２mmの範囲、好ましくは約0.1mm〜1.0mmの範囲に
すると、両方の特性がかねそなえられることがわ
かつた。
更に被覆ガラスについて述べると、被覆ガラス
は、被覆作業中に熱電耐を酸化させにくい方が望
ましい。これは、本発明では、比較的高い軟化温
度を有するガラスが用いられる為被覆作業中、熱
電対を特に酸化させやすい事による。
熱電対を酸化させにくいガラスとしては、
B2O3−PbO−ZnO系、Na2O−Al2O3−SiO2系、
MgO−Al2O3−SiO2系、Li2O−Al2O3−SiO2系、
Na2O−CaO−mgO−SiO2系または、ZnO−
B2O3−SiO2系の結晶化ガラスがある。結晶化ガ
ラスは、比較的低温の結晶温度で融着可能である
が、この温度よりかなり高温の軟化点まで固化状
態を保つ。したがつて、比較的低温で被覆作業が
でき、熱電対が酸化されにくい。又、結晶化ガラ
スは8500Kg／mm2〜12000Kg／mm2程度の弾性係数を
有し、機械的強度に優れる為、薄くしやすく熱応
答性の改善に役立つ。前述した各系の結晶化ガラ
スのうち、B2O3−PbO−ZnO系の結晶化ガラス
の組成を一例として第１表に示す。
TECHNICAL FIELD OF THE INVENTION The present invention relates to thermocouples, and more particularly to improvements in temperature sensing ends. [Technical Background of the Invention and Problems Therewith] Many commonly used thermocouples have a structure in which their temperature detection portion is directly exposed to the measurement atmosphere. Examples of thermocouple materials include chromel-alumel, chromel-constantan, and iron-constantan.
The temperature sensing end may be oxidized, causing a change in electromotive force and destruction of the junction. The inventors of the present invention therefore considered solving this problem by covering the temperature detection section with glass. However, this type of thermocouple may not be able to withstand use in high-temperature regions or during rapid temperature changes, and it has been desired to further solve this problem. [Object of the Invention] The thermocouple of the present invention is intended for use in high-temperature areas or during rapid temperature changes, and provides thermoelectric resistance that (1) has relatively good heat resistance and (2) has oxidation resistance. It's about doing. [Summary of the invention] The thermocouple according to the present invention comprises chromel-alumel,
A thermocouple made of a material selected from chromel-constantan or iron-constantan, B 2 O 3 −PbO−ZnO system, Na 2 O−Al 2 O 3 −SiO 2
system, MgO−Al 2 O 3 −SiO 2 system, Li 2 O−Al 2 O 3 −SiO 2
system, Na 2 O−CaO−MgO−SiO 2 system or ZnO−
Selected from B 2 O 3 −SiO 2 system and 5.0×10 -6 /deg
It is characterized by having a sensing end coated with crystallized glass having a thickness of 0.01 mm to 2 mm and having a coefficient of thermal expansion in the range of ~40×10 -6 /deg and a softening point of 600°C or higher. In order to improve the oxidation resistance of the sensing end, the sensing end is coated with glass in the present invention. This dramatically improves oxidation resistance. Furthermore, since the detection end has a relatively complicated shape, glass, which is easy to process, is suitable for covering it. However, depending on the glass, there may be cases where the heat resistance is insufficient. Therefore, we investigated glass in order to have heat resistance. As a result, 5.0×10 -6 /deg ~ 40×10 -6 /deg
It has been found that the above requirements can be met by using a glass having a coefficient of thermal expansion in the range of and a softening point of 600° C. or higher. This means that the coefficient of thermal expansion of glass is approximately 5.0×10 -6 /
degree to about 40×10 -6 /deg, the coefficient is relatively close to that of metal, the glass layer is less likely to peel off due to thermal shock, and the heat resistance can be improved. The maximum operating temperature is determined by the softening point, and it is used below this temperature, but the softening point of glass is approximately
This is because when the temperature is 600°C or higher, the range of use thereof is expanded to a higher temperature side than that of plate glass, and the heat resistance can be improved. This type of glass includes crystallized glass. The above has described thermoelectric resistance, which has both heat resistance and oxidation resistance, but there are cases where even faster thermal response is required. Therefore, the following method can be considered as a method that also has thermal conductivity. The goal is to reduce the thickness of the coated glass. Thereby, it is possible to improve thermal conductivity. However, if it is too thin, the mechanical strength will decrease and the glass will break. In the present invention, as a result of studying these conflicting demands, it was found that these demands can be met by adjusting the thickness of the glass. In other words, the thickness of the glass to be coated should be approximately 0.01mm ~
It has been found that a range of 2 mm, preferably about 0.1 mm to 1.0 mm, provides both properties. Furthermore, regarding the coated glass, it is desirable that the coated glass has thermoelectric resistance that is less likely to be oxidized during the coating operation. This is because, in the present invention, glass having a relatively high softening temperature is used, which makes the thermocouple particularly susceptible to oxidation during the coating operation. As a glass that does not easily oxidize thermocouples,
B2O3 - PbO-ZnO system, Na2O - Al2O3 - SiO2 system,
MgO−Al 2 O 3 −SiO 2 system, Li 2 O−Al 2 O 3 −SiO 2 system,
Na 2 O−CaO−mgO−SiO 2 system or ZnO−
There is a B 2 O 3 −SiO 2 type crystallized glass. Crystallized glass can be fused at relatively low crystallization temperatures, but remains solid until its softening point, which is significantly higher than this temperature. Therefore, the coating can be performed at a relatively low temperature, and the thermocouple is less likely to be oxidized. Further, crystallized glass has an elastic modulus of about 8500 Kg/mm 2 to 12000 Kg/mm 2 and has excellent mechanical strength, so it can be easily made thin and useful for improving thermal response. Among the above-mentioned types of crystallized glasses, the composition of B 2 O 3 -PbO-ZnO-based crystallized glass is shown in Table 1 as an example.
実施例 １
本発明の熱電対の一実施例を図面を用いて説明
する。アルメル線１にクロメル線２を接合した検
出端部３を、熱膨張係数が約9.0×10−6／deg、
結晶化温度が約620℃、軟化点が約960℃、厚さ約
0.9mmの結晶化ガラス４で被覆した。その際、熱
電対はほとんど酸化されなかつた。
この熱電対を用いて、大気雰囲気で、室温から
約850℃の温度範囲で耐酸化試験及び急冷試験を
行つたところ、耐熱性および耐酸化性が良好であ
ることがわかつた。更に、熱応答性は常温から沸
騰している水の中に熱電対を入れ電位差計で電圧
を測定し、常温と沸騰している水との温度差の90
％に相当する電圧に変化するまでの時間を計るこ
とによつて調べられた。その結果、熱応答性は比
較的良好であつた。
〔発明の効果〕
本発明のクロメル−アルメル、クロメル−コン
スタンタンまたは、鉄−コンスタンタンから選ば
れる熱電対は、検出端部を、B2O3−PbO−ZnO
系、Na2O−Al2O3−SiO2系、MgO−Al2O3−
SiO2系、Li2O−Al2O3−SiO2系、NaO2−CaO−
MgO−SiO2系または、ZnO−B2O3−SiO2系から
選ばれ、かつ5.0×10-6／deg〜40×10-6／degの
範囲の熱膨張係数、600℃以上の軟化点を有する
厚さ0.01mm〜２mmの結晶化ガラスで被覆すること
により、比較的高温で良好な耐酸化性及び耐熱性
を有する。
Example 1 An example of the thermocouple of the present invention will be described with reference to the drawings. The detection end 3, which is made by joining the alumel wire 1 and the chromel wire 2, has a thermal expansion coefficient of approximately 9.0× 10−6 /deg.
Crystallization temperature is approximately 620℃, softening point is approximately 960℃, thickness is approximately
It was coated with 0.9 mm of crystallized glass 4. At that time, the thermocouple was hardly oxidized. Using this thermocouple, we conducted an oxidation resistance test and a quenching test in the air atmosphere at a temperature range from room temperature to approximately 850°C, and found that it had good heat resistance and oxidation resistance. Furthermore, the thermal response is measured by placing a thermocouple in water that is at room temperature to boiling and measuring the voltage with a potentiometer.
This was determined by measuring the time it takes for the voltage to change to a value corresponding to %. As a result, the thermal response was relatively good. [Effects of the Invention] The thermocouple of the present invention selected from chromel-alumel, chromel-constantan, or iron-constantan has a detection end of B 2 O 3 −PbO−ZnO.
system, Na 2 O−Al 2 O 3 −SiO 2 system, MgO−Al 2 O 3 −
SiO 2 system, Li 2 O−Al 2 O 3 −SiO 2 system, NaO 2 −CaO−
Selected from MgO-SiO 2 system or ZnO-B 2 O 3 -SiO 2 system, and has a thermal expansion coefficient in the range of 5.0 × 10 -6 /deg to 40 × 10 -6 /deg, and a softening point of 600 ° C or more. By coating with crystallized glass having a thickness of 0.01 mm to 2 mm, it has good oxidation resistance and heat resistance at relatively high temperatures.
図面は本発明の熱電対の一実施例を示す断面図
である。
３……検出端部、４……ガラス。
The drawing is a sectional view showing an embodiment of the thermocouple of the present invention. 3...Detection end, 4...Glass.
Claims (1)
タンまたは、鉄−コンスタンタンから選ばれる熱
電対において、該熱電対は、B2O3−PbO−ZnO
系、Na2O−Al2O3−SiO2系、MgO−Al2O3−
SiO2系、Li2O−Al2O3−SiO2系、Na2O−CaO−
MgO−SiO2系または、ZnO−B2O3−SiO2系から
選ばれ、かつ5.0×10-6／deg〜40×10-6／degの
範囲の熱膨張係数、600℃以上の軟化点を有する
厚さ0.01mm〜２mmの結晶化ガラスで被覆された検
出端部を具備してなる熱電対。1. A thermocouple selected from chromel-almel, chromel-constantan, or iron-constantan, wherein the thermocouple is B 2 O 3 -PbO-ZnO
system, Na 2 O−Al 2 O 3 −SiO 2 system, MgO−Al 2 O 3 −
SiO 2 system, Li 2 O−Al 2 O 3 −SiO 2 system, Na 2 O−CaO−
Selected from MgO-SiO 2 system or ZnO-B 2 O 3 -SiO 2 system, and has a thermal expansion coefficient in the range of 5.0 × 10 -6 /deg to 40 × 10 -6 /deg, and a softening point of 600 ° C or more. A thermocouple comprising a detection end coated with crystallized glass having a thickness of 0.01 mm to 2 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57168578A JPS5958883A (en) | 1982-09-29 | 1982-09-29 | Thermocouple |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57168578A JPS5958883A (en) | 1982-09-29 | 1982-09-29 | Thermocouple |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5958883A JPS5958883A (en) | 1984-04-04 |
| JPH059949B2 true JPH059949B2 (en) | 1993-02-08 |
Family
ID=15870643
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57168578A Granted JPS5958883A (en) | 1982-09-29 | 1982-09-29 | Thermocouple |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5958883A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113340465B (en) * | 2021-04-29 | 2023-05-05 | 慧石（上海）测控科技有限公司 | Quick response temperature sensing probe and temperature sensor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS572584A (en) * | 1980-06-06 | 1982-01-07 | Tdk Corp | Thermoelectric element and manufacture thereof |
-
1982
- 1982-09-29 JP JP57168578A patent/JPS5958883A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5958883A (en) | 1984-04-04 |
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