JPS62162924A - Continuous level gage - Google Patents

Continuous level gage

Info

Publication number
JPS62162924A
JPS62162924A JP454086A JP454086A JPS62162924A JP S62162924 A JPS62162924 A JP S62162924A JP 454086 A JP454086 A JP 454086A JP 454086 A JP454086 A JP 454086A JP S62162924 A JPS62162924 A JP S62162924A
Authority
JP
Japan
Prior art keywords
liquid level
sensing element
ratio
current flowing
liquid
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.)
Granted
Application number
JP454086A
Other languages
Japanese (ja)
Other versions
JPH0643915B2 (en
Inventor
Etsuro Habata
悦朗 幅田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP61004540A priority Critical patent/JPH0643915B2/en
Publication of JPS62162924A publication Critical patent/JPS62162924A/en
Publication of JPH0643915B2 publication Critical patent/JPH0643915B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Abstract

PURPOSE:To prevent overheating in a liquid by paralleling the direction of a line connecting both electrodes of a detecting element consisting of a positive characteristic thermistor to a liquid level and making it possible to indicate a continuous change of the liquid level with simple constitution. CONSTITUTION:When the whole of the long-sized detecting element 6 consisting of the positive characteristic thermistor is in the air, the heat dissipation coefficient is reduced and the element 6 generates heat for itself and attains thermal equilibrium with high temperature. On the other hand, the resistance of the element 6 is reduced when the whole element 6 is in gasoline. Then, an electric current value of the element 6 is changed in a straight line as the element 6 is dipped in order from its end part. The change of the liquid level can be continuously indicated by reading the change of the electric current. In this case, the element 6 is fixed so that the direction of the line connecting the electrodes 7 provided to both main surfaces of the thermistor is paralleled to the liquid level.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は自動車などの燃料の量を、正特性サーミスタの
自己発熱の程度が液中と空中とで異なることを利用して
検知し表示するもので、液面の変化を連続的に表示でき
る連続式液位計に関するものである。
[Detailed Description of the Invention] Industrial Application Field The present invention detects and displays the amount of fuel in automobiles, etc. by utilizing the fact that the degree of self-heating of a positive temperature coefficient thermistor differs between in liquid and in air. , relates to a continuous liquid level gauge that can continuously display changes in liquid level.

従来の技術 正特性サーミスタは、温度が上昇するとある温度cキュ
リ一温度)以上に々ると急激に抵抗値が上昇する性質を
持った感温抵抗体で、半導体セラミクスや高分子材料か
らなっている。これに電圧を印加して自己発熱させた場
合、その素子が空中にある時とガソリンなどの液中にあ
る時とでは温度が異なシ、ひいてはその抵抗値が異なる
ことを利用して液面センサとして用いることができる。
Conventional technology A positive temperature coefficient thermistor is a temperature-sensitive resistor that has the property of rapidly increasing its resistance when the temperature rises above a certain temperature (C Curie temperature), and is made of semiconductor ceramics or polymer materials. There is. If a voltage is applied to this element to generate self-heating, the temperature will be different when the element is in the air and when it is in a liquid such as gasoline, and the resistance value will also be different. It can be used as

従来のこの種の液位計は、負特性サーミスタを用いたも
のが実用化されている。第6図でその構成を示す。第6
図において、1はロンド状の負特性サーミスタによる検
知素子で、2はそれに固着されているニッケルなどのリ
ード線である。3は絶縁板、4は金属筒で、これらでケ
ースを構成し、この中央部に前記検知素子1がリード線
2を介して固定されている。5はランプであり、これに
検知素子1と電源とを直列に接続しである。
Conventional liquid level gauges of this type using negative characteristic thermistors have been put into practical use. FIG. 6 shows its configuration. 6th
In the figure, numeral 1 is a sensing element made of a Rondo-shaped negative characteristic thermistor, and numeral 2 is a lead wire made of nickel or the like fixed thereto. Reference numeral 3 indicates an insulating plate, and 4 indicates a metal tube, which together constitute a case, to the center of which the detection element 1 is fixed via a lead wire 2. 5 is a lamp, to which the detection element 1 and a power source are connected in series.

このような液位計において、検知素子1が空中にある時
は、検知素子1の熱放散係数が小さいため、発熱しやす
く温度が高くなる。そのため検知素子1の抵抗が小さく
なり、流れる電流が大きく、ランプ5が点灯する。また
、金属筒4が液中にある時は、透孔aから液が入り、検
知素子1が液に浸漬される。この時は検知素子1の熱が
液に奪われ、熱放散係数が大きくなるので、検知素子1
の抵抗が大きくなって回路に流れる電流が少なくなり、
ランプ5が消灯する。
In such a liquid level gauge, when the sensing element 1 is in the air, the heat dissipation coefficient of the sensing element 1 is small, so it is easy to generate heat and the temperature becomes high. Therefore, the resistance of the sensing element 1 becomes small, the current flowing becomes large, and the lamp 5 lights up. Further, when the metal cylinder 4 is in the liquid, the liquid enters through the through hole a, and the sensing element 1 is immersed in the liquid. At this time, the heat of the sensing element 1 is taken away by the liquid and the heat dissipation coefficient increases, so the sensing element 1
The resistance increases and the current flowing through the circuit decreases,
Lamp 5 goes out.

第7図、第8図はさらに別の従来例で、第6図に示した
負特性サーミスタを複数個用い、液面の変化を段階的に
表示できるものである。(実開昭57−105930号
公報) 発明が解決しようとする問題点 従来の液位計は、負特性サーミスタの自己発熱の量が液
中と空気中で大きく異なることを利用して、その抵抗値
が液中と空気中で異なり、流れる電流の大小により、ラ
ンプが点灯及び消灯するものである。そのため、非常に
簡単な回路で液の有無が表示できる。しかしながら、検
知素子が1ケであるため、表示できる液位は検知素子が
液中にあるか空中にあるかという、ただ一点のみであり
、液位の変化を連続的に表示することができなかった。
FIGS. 7 and 8 show still another conventional example, in which a plurality of the negative characteristic thermistors shown in FIG. 6 are used to display changes in the liquid level step by step. (Utility Model Publication No. 57-105930) Problems to be Solved by the Invention Conventional liquid level gauges take advantage of the fact that the amount of self-heating of a negative characteristic thermistor differs greatly between the liquid and the air. The value is different in the liquid and in the air, and the lamp turns on and off depending on the magnitude of the current flowing. Therefore, the presence or absence of liquid can be displayed using a very simple circuit. However, since there is only one sensing element, the liquid level that can be displayed is only one point, whether the sensing element is in the liquid or in the air, and changes in the liquid level cannot be displayed continuously. Ta.

そのため、検知素子を複数個用いる構造も考案されてい
るが、これでも液位を段階的に表示するだけで、連続的
に液位の量を表示することはできなかった。
Therefore, a structure using a plurality of sensing elements has been devised, but even this can only display the liquid level in stages, but cannot continuously display the amount of liquid level.

また、検知素子に負特性サーミスタを用いているため、
周囲温度が上昇すると液中にある場合でも検知素子の温
度が上昇し、液温の上昇が大きくなっていた。
In addition, since a negative characteristic thermistor is used as the detection element,
When the ambient temperature rises, the temperature of the sensing element rises even when it is in the liquid, resulting in a large increase in the liquid temperature.

問題点を解決するだめの手段 この問題点を解決するために本発明は、液面の変化に伴
ない浸漬する長さが変化するように固定された正特性サ
ーミスタからなる長尺の検知素子と、その検知素子に直
列に接続された電源及びその直列回路に流れる電流の表
示装置からなり、前記検知素子の両電極を結ぶ線の方向
が液面に平行にしたものである。
Means for Solving the Problem In order to solve this problem, the present invention uses a long sensing element consisting of a positive temperature coefficient thermistor fixed so that the immersion length changes as the liquid level changes. It consists of a power supply connected in series to the sensing element and a display device for the current flowing through the series circuit, and the direction of the line connecting both electrodes of the sensing element is parallel to the liquid level.

作用 この構成による作用を説明する。まず正特性サーミスタ
は温度が上昇すると、ある温度(キュリ一温度)以上で
急激に抵抗値が上昇する感温抵抗体で、チタン酸バリウ
ム系の半導体セラミクスや、高分子樹脂に導電粉を混合
したものなどで作成できる。この正特性サーミスタで構
成された長尺の検知素子に電圧を印加し、検知素子全体
が空中にある時、検知素子は自己発熱し、抵抗が大きく
なっである温度で熱平衡に達する。この時、回路に流れ
る電流もある一定の電流で安定する。その電流値は電流
の表示装置で表示されている。そして、液位が増加して
検知素子の端部から次第に浸漬されていくと、その浸漬
された部分の温度が低くなり、そこの部分の抵抗が小さ
くなる。すると、検知素子の一部の抵抗が減少するので
、電流はそれに応じて増大する。一方、検知素子全体が
液中に浸漬すると、電流は最も大きくなる。このように
液位に応じて電流が連続的に変化し、その値を電流表示
装置で読み取ることができる。まだ、検知素子の両電極
を結ぶ線を液面に垂直にした場合、検知素子の空中にあ
る部分と、液中にある部分が直列に接続されたようにな
り、空中にある部分の抵抗値が高くなり、そこに電圧が
集中し液中の部分に電圧が印加されなくなる。そのため
、検知素子の両電極を結ぶ線は液面に平行である必要が
ある。
Effect The effect of this configuration will be explained. First of all, a positive temperature coefficient thermistor is a temperature-sensitive resistor whose resistance value increases sharply when the temperature rises above a certain temperature (Currie temperature), and is made of barium titanate-based semiconductor ceramics or polymer resin mixed with conductive powder. It can be created with things. When a voltage is applied to a long sensing element made of this positive temperature coefficient thermistor and the entire sensing element is in the air, the sensing element self-heats, its resistance increases, and it reaches thermal equilibrium at a certain temperature. At this time, the current flowing through the circuit also stabilizes at a certain constant current. The current value is displayed on a current display device. Then, as the liquid level increases and the sensing element is gradually immersed from the end, the temperature of the immersed part becomes lower and the resistance of that part becomes smaller. Then, since the resistance of a portion of the sensing element decreases, the current increases accordingly. On the other hand, when the entire sensing element is immersed in the liquid, the current becomes the largest. In this way, the current changes continuously depending on the liquid level, and its value can be read on the current display device. However, if the line connecting both electrodes of the sensing element is made perpendicular to the liquid level, the part of the sensing element in the air and the part in the liquid will be connected in series, and the resistance value of the part in the air will be becomes high, the voltage is concentrated there, and no voltage is applied to the part in the liquid. Therefore, the line connecting both electrodes of the sensing element needs to be parallel to the liquid level.

実施例 第1図は本発明の一実施例による連続式液位計を示す概
略構成図であり、第1図において、6は板状の正特性サ
ーミスタによる長尺の検知素子で、例えば形状は厚さ1
mmX幅2 mm X長さ100mmであり、常温抵抗
値は3Ω、キュリ一温度は60℃である。この検知素子
6は液面の変化に伴ない浸漬する長さが変化するように
取付けられる。7は前記正特性サーミスタの両主面に設
けられた電極であり、この両面の電極7を結ぶ線の方向
が液面と平行となるように検知素子6は固定される。8
は検知素子6に直列に接続された電源で12V、9は電
流計で検知素子6に流れる電流を表示するものである。
Embodiment FIG. 1 is a schematic configuration diagram showing a continuous liquid level meter according to an embodiment of the present invention. In FIG. Thickness 1
It is 2 mm wide x 100 mm long, has a room temperature resistance of 3Ω, and a Curie temperature of 60°C. This sensing element 6 is mounted so that the length of immersion changes as the liquid level changes. Reference numeral 7 denotes electrodes provided on both main surfaces of the PTC thermistor, and the sensing element 6 is fixed so that the direction of the line connecting the electrodes 7 on both surfaces is parallel to the liquid level. 8
9 is a power supply connected in series to the sensing element 6 at 12V, and 9 is an ammeter that displays the current flowing through the sensing element 6.

今、検知素子全体が空中にある時は、熱放散係数が小さ
いので検知素子は自己発熱し、高い温度で熱平衡に達す
る。そのため検知素子の抵抗値は高くなる。この時の電
流は100m人であった。
Now, when the entire sensing element is in the air, the heat dissipation coefficient is small, so the sensing element self-heats and reaches thermal equilibrium at a high temperature. Therefore, the resistance value of the sensing element becomes high. The current at this time was 100m.

逆に、検知素子全体がガソリン中にある時は抵抗が低く
、電流はaoomAであった。また、検知素子の端部か
ら順次浸漬されていくと、電流値はそれに応じて100
m人から800m人までほぼ直線的に変化する。
Conversely, when the entire sensing element was in gasoline, the resistance was low and the current was aoomA. Also, when the sensing element is immersed sequentially from the end, the current value increases accordingly.
It changes almost linearly from m people to 800 m people.

このように特別な回路を用いずに、非常に簡単な構成で
、電流の変化を読み取るだけで、液位の変化を連続的に
示すことができる。まだ、正特性サーミスタを用いてい
るので、自己温度制御作用を有し、表面温度は周囲温度
が上昇してもほぼ一定で過熱することはない。
In this way, with a very simple configuration and without using any special circuits, changes in liquid level can be continuously indicated simply by reading changes in current. However, since a positive temperature coefficient thermistor is used, it has a self-temperature control function, and even if the ambient temperature rises, the surface temperature remains almost constant and does not overheat.

第2図は正特性サーミスタによる検知素子の別の実施例
の斜視図である。第2図において、1゜は正特性サーミ
スタで、11はそれの両主面につけられた銀などの電極
である。第3図に示す12はこの小さな正特性サーミス
タ1oを並列に複数個はぼ密着させて、黄銅板などの共
通電極13を用いて半田など(図示せず)で固着した検
知素子である。一般に、正特性サーミスタなどのセラミ
ックはもろくて、本発明に用いるような長尺な形状を作
成するのが困難であるが、第3図に示したような構成で
検知素子を構成すると、小さな形状の正特性サーミスタ
を用いることができ、歩留まりが良く、簡単に長尺な検
知素子を作成することができる。
FIG. 2 is a perspective view of another embodiment of a sensing element using a positive temperature coefficient thermistor. In FIG. 2, 1° is a positive temperature coefficient thermistor, and 11 is an electrode made of silver or the like attached to both main surfaces of the thermistor. Reference numeral 12 in FIG. 3 is a sensing element in which a plurality of these small positive temperature coefficient thermistors 1o are closely connected in parallel and fixed with solder or the like (not shown) using a common electrode 13 such as a brass plate. In general, ceramics such as positive temperature coefficient thermistors are brittle and it is difficult to create a long shape as used in the present invention. However, if the sensing element is configured as shown in Fig. A positive temperature coefficient thermistor can be used, the yield is high, and a long sensing element can be easily produced.

第4図は、温度補償を簡単な構成で広い温度範囲で使用
可能にしだ本発明の別の実施例である。
FIG. 4 shows another embodiment of the present invention which allows temperature compensation to be used over a wide temperature range with a simple configuration.

14は長尺の正特性サーミスタによる検知素子で、前述
したように液への浸漬長さに応じてその抵抗値は変化す
る。16は同様に正特性サーミスタによる温度補償用素
子で、常に液中にあるいは空中にあるか、または形状を
大きくして、液中と空中での発熱量の差をほとんどなく
し、その抵抗は周囲温度のみによってきまるようにした
ものである。
Reference numeral 14 denotes a sensing element consisting of a long positive temperature coefficient thermistor, and as described above, its resistance value changes depending on the length of immersion in the liquid. Similarly, numeral 16 is a temperature compensation element using a positive temperature coefficient thermistor, which is always in the liquid or in the air, or has a large shape to almost eliminate the difference in heat generation between the liquid and the air, and its resistance is proportional to the ambient temperature. It was decided only by

16は交叉コイル比率計である。この交叉コイル比率計
16は、交叉した2つのコイルを用いて、その2つのコ
イルに流れる電流の比を表示できるものである。
16 is a crossed coil ratio meter. This crossed coil ratio meter 16 uses two crossed coils and can display the ratio of currents flowing through the two coils.

そして、一方のコイルC1には検知素子14に流れる電
流を流し、他方のコイルC2には温度補償用素子16に
流れる電流を流す。
A current flowing to the sensing element 14 is passed through one coil C1, and a current flowing to the temperature compensation element 16 is passed through the other coil C2.

ここで、温度補償用素子を用いない場合、検知素子に流
れる電流は液中と空中で大きく異なるが、さらに周囲温
度によっても異なり、広い温度範囲で電流値のみで液位
を表示することは困難であった。なお、第4図で17は
鉄などの磁性体、18は指針である。
Here, if a temperature compensation element is not used, the current flowing through the sensing element differs greatly between the liquid and the air, but it also varies depending on the ambient temperature, making it difficult to display the liquid level with only the current value over a wide temperature range. Met. In addition, in FIG. 4, 17 is a magnetic material such as iron, and 18 is a pointer.

第4図に示す実施例では、温度補償用素子を用い、検知
素子に流れる電流と温度補償用素子に流れる電流との比
が、液位が一定であれば周囲温度が変っても一定にし、
広い温度範囲で液位の表示を可能にしたものである。ま
た、両者に流れる電流の比を表示するのに、交叉コイル
比率計を用いると、簡単で安価にその電流の比を表示で
きる。
In the embodiment shown in FIG. 4, a temperature compensation element is used, and the ratio of the current flowing through the sensing element and the current flowing through the temperature compensation element is kept constant even if the ambient temperature changes as long as the liquid level is constant.
This makes it possible to display the liquid level over a wide temperature range. Furthermore, if a crossed coil ratio meter is used to display the ratio of the currents flowing through both, the ratio of the currents can be displayed easily and inexpensively.

第6図aは温度補償用素子を用いない場合の検知素子に
流れる電流11の様子を示し、周囲温度によって特性が
大きく変化していることが解る。
FIG. 6a shows the state of the current 11 flowing through the sensing element when no temperature compensation element is used, and it can be seen that the characteristics change greatly depending on the ambient temperature.

一方、第5図すは温度補償用素子を用い、それに流れる
電流±2と11との比i1/i2 の様子を示しだもの
である。この場合、i 2 /i + は周囲温度によ
らず、液面の変化、のみによって決まっている。
On the other hand, FIG. 5 shows the ratio i1/i2 of the current ±2 to 11 flowing through a temperature compensating element. In this case, i 2 /i + is determined only by the change in the liquid level, not by the ambient temperature.

なお、本実施例では検知素子の形状を板状のものと、半
田で接合したもののみを示したが、棒状あるいはフィル
ム状、薄膜状のものでも良い。まだ、直列回路の中に適
宜固定抵抗を挿入しても良い0 発明の効果 以上のように本発明によれば、検知素子として長尺な正
特性サーミスタを用いることにより、特別な増幅回路な
どを用いることなく、簡単な構成で液位の連続した変化
を表示でき、また液中での過熱の恐れのない実用的価値
の大なるものである。
In this embodiment, only the plate-shaped sensing element and the one joined by solder are shown as the sensing element, but the sensing element may be rod-shaped, film-shaped, or thin-film shaped. However, a fixed resistor may be inserted as appropriate in the series circuit. Effects of the Invention As described above, according to the present invention, by using a long positive temperature coefficient thermistor as a detection element, a special amplifier circuit etc. can be used. It is possible to display continuous changes in the liquid level with a simple configuration without using it, and it has great practical value because there is no risk of overheating in the liquid.

【図面の簡単な説明】[Brief explanation of drawings]

第1図は本発明の一実施例による連続式液位計し、ら を示す概略構成図、第2図女←等i→は本発明に用いる
検知素子の構成例を説明する斜視図、第1図は本発明に
おける連続式液位計の他の実施例をそれぞれ従来の液位
計を示す概略構成図及び回路図である。 6.12.14・・・・・・検知素子、10・・・・・
・正特性サーミスタ、7,11・・・・・・電極、16
・・・・・・温度補償用素子、16・・・・・・交叉コ
イル比率計。 代理人の氏名 弁理士 中 尾 敏 男 ほか1名第3
図 第4図 (a−)       (b) 句じ…系り浸漬に−本りr卆3っ浸鼾さ−第5図
FIG. 1 is a schematic configuration diagram showing a continuous liquid level meter according to an embodiment of the present invention, FIG. 2 is a perspective view illustrating an example of the configuration of a sensing element used in the present invention, FIG. 1 is a schematic configuration diagram and a circuit diagram showing another embodiment of the continuous liquid level gauge according to the present invention and a conventional liquid level gauge, respectively. 6.12.14...Detection element, 10...
・Positive characteristic thermistor, 7, 11... Electrode, 16
...Temperature compensation element, 16...Cross coil ratio meter. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 4 (a-) (b) Phrases... System immersion - Honri r volume 3 immersion snoring - Figure 5

Claims (4)

【特許請求の範囲】[Claims] (1)液面の変化に伴い浸漬する長さが変化するように
固定された正特性サーミスタからなる長尺の検知素子と
、その検知素子に直列に接続された電源と、その検知素
子に流れる電流の表示装置とからなり、前記検知素子の
両電極を結ぶ線の方向が液面に平行である連続式液位計
(1) A long sensing element consisting of a positive temperature coefficient thermistor fixed so that the immersion length changes as the liquid level changes, a power supply connected in series to the sensing element, and a current flowing through the sensing element. A continuous liquid level meter comprising a current display device, wherein the direction of a line connecting both electrodes of the sensing element is parallel to the liquid level.
(2)並列に接続され、かつそれぞれがほぼ密着して固
着された複数の正特性サーミスタによる検知素子を用い
た特許請求の範囲第1項記載の連続式液位計。
(2) A continuous liquid level gauge according to claim 1, which uses detection elements consisting of a plurality of positive temperature coefficient thermistors connected in parallel and each of which is substantially closely fixed.
(3)電流表示装置として2つの電流の比を示す比率計
を用い、検知素子に流れる電流と、常時液中または空気
中にあるように固定されているかまたは検知素子より大
きな形状で液中と空気中での発熱温度がほぼ等しくなる
別の正特性サーミスタによる温度補償用素子に流れる電
流との比を、前記比率計で表示するようにした特許請求
の範囲第1項記載の連続式液位計。
(3) A ratio meter that shows the ratio of two currents is used as a current display device, and the current flowing to the sensing element and the current flowing to the sensing element, which is fixed so that it is always in the liquid or air, or which is larger than the sensing element and is in the liquid. The continuous liquid level according to claim 1, wherein the ratio meter displays a ratio to a current flowing through a temperature compensation element using another positive temperature coefficient thermistor whose heat generation temperature in the air is approximately equal. Total.
(4)2つの電流の比を示す比率計に交叉コイル比率計
を用いた特許請求の範囲第3項記載の連続式液位計。
(4) The continuous liquid level meter according to claim 3, which uses a crossed coil ratio meter as the ratio meter that indicates the ratio of two currents.
JP61004540A 1986-01-13 1986-01-13 Continuous level gauge Expired - Lifetime JPH0643915B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP61004540A JPH0643915B2 (en) 1986-01-13 1986-01-13 Continuous level gauge

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP61004540A JPH0643915B2 (en) 1986-01-13 1986-01-13 Continuous level gauge

Publications (2)

Publication Number Publication Date
JPS62162924A true JPS62162924A (en) 1987-07-18
JPH0643915B2 JPH0643915B2 (en) 1994-06-08

Family

ID=11586875

Family Applications (1)

Application Number Title Priority Date Filing Date
JP61004540A Expired - Lifetime JPH0643915B2 (en) 1986-01-13 1986-01-13 Continuous level gauge

Country Status (1)

Country Link
JP (1) JPH0643915B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991010116A1 (en) * 1989-12-28 1991-07-11 Hope Bjoern R A method and a device for determining the positions of boundary layers
JP2020106187A (en) * 2018-12-27 2020-07-09 パナソニックIpマネジメント株式会社 Humidifier
JP2020106189A (en) * 2018-12-27 2020-07-09 パナソニックIpマネジメント株式会社 Humidifier

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5763230U (en) * 1980-09-30 1982-04-15
JPS59148826A (en) * 1983-02-14 1984-08-25 Matsushita Electric Ind Co Ltd Liquid level sensor
JPS6014127A (en) * 1983-06-17 1985-01-24 ザ・パーキン―エルマー コーポレイション Device for remotely measuring liquid level

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5763230U (en) * 1980-09-30 1982-04-15
JPS59148826A (en) * 1983-02-14 1984-08-25 Matsushita Electric Ind Co Ltd Liquid level sensor
JPS6014127A (en) * 1983-06-17 1985-01-24 ザ・パーキン―エルマー コーポレイション Device for remotely measuring liquid level

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991010116A1 (en) * 1989-12-28 1991-07-11 Hope Bjoern R A method and a device for determining the positions of boundary layers
JP2020106187A (en) * 2018-12-27 2020-07-09 パナソニックIpマネジメント株式会社 Humidifier
JP2020106189A (en) * 2018-12-27 2020-07-09 パナソニックIpマネジメント株式会社 Humidifier

Also Published As

Publication number Publication date
JPH0643915B2 (en) 1994-06-08

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