JPH0727582A - Mass flow sensor - Google Patents
Mass flow sensorInfo
- Publication number
- JPH0727582A JPH0727582A JP5194040A JP19404093A JPH0727582A JP H0727582 A JPH0727582 A JP H0727582A JP 5194040 A JP5194040 A JP 5194040A JP 19404093 A JP19404093 A JP 19404093A JP H0727582 A JPH0727582 A JP H0727582A
- Authority
- JP
- Japan
- Prior art keywords
- mass flow
- resistors
- heat
- sensitive resistor
- resistor
- 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
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、流体の質量流量を計測
するマスフローメータまたは流体の質量流量を計測し流
体流量を制御するマスフローコントローラに用いられる
質量流量センサに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mass flow sensor used in a mass flow meter for measuring a mass flow rate of a fluid or a mass flow controller for measuring a mass flow rate of a fluid and controlling the fluid flow rate.
【０００２】[0002]
【従来の技術】図６は、従来より一般的に用いられてい
るマスフローメータを示すもので、この図において、１
は本体ブロックで、その一端側には流体入口２が形成さ
れ、他端側には流体出口３が形成されると共に、内部に
流体入口２と流体出口３とを結ぶようにして流体流路４
が形成してあり、この流体流路４には定流量特性を有す
るバイパス素子５が設けてあって、バイパス部６に構成
されている。2. Description of the Related Art FIG. 6 shows a mass flow meter generally used in the past.
Is a main body block, a fluid inlet 2 is formed at one end side thereof, a fluid outlet 3 is formed at the other end side thereof, and a fluid flow path 4 is formed by connecting the fluid inlet 2 and the fluid outlet 3 inside.
Is formed, and the fluid flow path 4 is provided with a bypass element 5 having a constant flow rate characteristic and is configured in the bypass section 6.
【０００３】７は本体ブロック１の上部に設けられるセ
ンサ固定ベースである。このセンサ固定ベース７には、
本体ブロック１内の流路４と連通路８を介して連通する
孔９を備えたスリーブ１０が着脱自在に設けてある。１
１はシール部材である。１２は質量流量センサで、スリ
ーブ１０に対して抵抗溶接などの手法により接続され、
センサ固定ベース７および本体ブロック１に垂直かつ逆
Ｕ字状に立設された測定流路としての細管１３と、この
細管１３の中央の水平部分１３ａの外周に巻設された２
つの感熱抵抗体１４，１５とからなる。なお、感熱抵抗
体１４，１５は、感熱特性などが互いに等しいものが選
ばれる。Reference numeral 7 is a sensor fixing base provided on the upper part of the main body block 1. In this sensor fixed base 7,
A sleeve 10 having a hole 9 communicating with the flow path 4 in the main body block 1 via a communication passage 8 is detachably provided. 1
Reference numeral 1 is a seal member. A mass flow sensor 12 is connected to the sleeve 10 by a technique such as resistance welding,
A thin tube 13 as a measurement flow path that is vertically installed in the sensor fixing base 7 and the main body block 1 in a vertical and inverted U shape, and 2 wound around the outer periphery of a horizontal portion 13a at the center of the thin tube 13.
It consists of two heat-sensitive resistors 14 and 15. The heat sensitive resistors 14 and 15 are selected to have the same heat sensitive characteristics.
【０００４】１６はセンサ固定ベース７の上面に抵抗溶
接などによって設けられるハーメチック端子で、感熱抵
抗体１４，１５は、ハーメチック端子１６のリードピン
を介して図外のブリッジ回路に接続される。１７はセン
サ部１２やハーメチック端子１６などを収納しこれらを
カバーするためのセンサケースである。なお、本体ブロ
ック１、スリーブ１０、細管１３などは、ステンレス、
ニッケル、コバールなどの耐腐食性に優れた金属よりな
る。Reference numeral 16 is a hermetic terminal provided on the upper surface of the sensor fixing base 7 by resistance welding or the like, and the thermosensitive resistors 14 and 15 are connected to a bridge circuit (not shown) via the lead pins of the hermetic terminal 16. Reference numeral 17 denotes a sensor case for accommodating and covering the sensor unit 12, the hermetic terminal 16, and the like. The body block 1, the sleeve 10, the thin tube 13, etc. are made of stainless steel,
It is made of metal with excellent corrosion resistance, such as nickel and kovar.
【０００５】[0005]
【発明が解決しようとする課題】ところで、上記構成の
マスフローメータにおいては、通常、図７（Ａ）に示す
ように、２つの感熱抵抗体１４，１５の高さ位置が互い
に等しい、質量流量センサ１２が水平な状態で取り付け
られる。このような水平姿勢で設置された質量流量セン
サ１２においては、細管１３の２個の感熱抵抗体１４，
１５が巻設された中央部分１３ａが水平になり、２つの
感熱抵抗体１４，１５の間に位置的に上下関係がないの
で、これらの感熱抵抗体１４，１５の間で熱対流が生ず
ることはない。By the way, in the mass flow meter having the above-mentioned structure, as shown in FIG. 7 (A), a mass flow sensor is generally used in which the two thermal resistors 14 and 15 have the same height position. 12 is mounted horizontally. In the mass flow sensor 12 installed in such a horizontal posture, the two heat-sensitive resistors 14 of the thin tube 13,
Since the central portion 13a around which 15 is wound is horizontal and there is no vertical relationship between the two heat sensitive resistors 14 and 15, thermal convection occurs between these heat sensitive resistors 14 and 15. There is no.
【０００６】しかしながら、配管系統の構成上あるいは
マスフローメータの設置スペースなどの関係で、図７
（Ｂ）に示すように、２つの感熱抵抗体１４，１５が巻
設された細管１３の中央部分１３ａが垂直となるよう
に、質量流量センサ１２を垂直姿勢の状態で設置しなけ
ればならないことがある。そのような場合、一方の感熱
抵抗体１５が他方の感熱抵抗体１４よりも上位に位置す
ることになり、細管１３の内部、外部の両方において熱
対流が生ずる。この熱対流によって両センサコイル１
４，１５が熱的に干渉しあい、ゼロ点が変化するため、
流量の測定結果に誤差が生ずる。However, depending on the configuration of the piping system or the installation space of the mass flow meter, the configuration shown in FIG.
As shown in (B), the mass flow sensor 12 must be installed in a vertical posture so that the central portion 13a of the thin tube 13 around which the two heat sensitive resistors 14 and 15 are wound is vertical. There is. In such a case, one heat-sensitive resistor 15 will be positioned higher than the other heat-sensitive resistor 14, and heat convection will occur both inside and outside the thin tube 13. Due to this heat convection, both sensor coils 1
Since 4, 15 thermally interfere with each other and the zero point changes,
An error occurs in the flow rate measurement result.
【０００７】このような垂直姿勢取付け時の不都合に対
して、細管１３の内径を小さくしたり、細管１３を流れ
る流体の差圧を上げることが試みられているが、このよ
うにしても、それほど測定誤差が低減することはできな
かった。[0007] In order to cope with such inconvenience when mounting in the vertical posture, it has been attempted to reduce the inner diameter of the thin tube 13 or increase the differential pressure of the fluid flowing through the thin tube 13. The measurement error could not be reduced.
【０００８】このような問題、すなわち、質量流量セン
サ１２の姿勢による影響は、マスフローメータに流体制
御弁を付加した構成であるところのマスフローコントロ
ーラにおいても生じているところである。Such a problem, that is, the influence of the attitude of the mass flow sensor 12 is occurring even in a mass flow controller having a structure in which a fluid control valve is added to a mass flow meter.
【０００９】本発明は、上述の事柄に留意してなされた
もので、その目的は、マスフローメータやマスフローコ
ントローラの取付け姿勢の如何に拘らず流体の質量流量
を精度よく検出できる質量流量センサを提供することに
ある。The present invention has been made in view of the above matters, and an object thereof is to provide a mass flow sensor capable of accurately detecting the mass flow rate of a fluid regardless of the mounting posture of a mass flow meter or a mass flow controller. To do.
【００１０】[0010]
【課題を解決するための手段】上記目的を達成するた
め、本発明に係る質量流量センサの一つは、マスフロー
メータまたはマスフローコントローラの本体ブロックに
逆Ｕ字状に立設され、内部に流体が流れる細管における
一つの垂直部分に第１感熱抵抗体と第２感熱抵抗体とを
互いに絶縁した状態で巻設し、他の垂直部分に第３感熱
抵抗体と第４感熱抵抗体とを互いに絶縁した状態で巻設
すると共に、第１感熱抵抗体と第３感熱抵抗体とを直列
接続したものと、第２感熱抵抗体と第４感熱抵抗体とを
直列接続したものとをそれぞれブリッジ回路の構成素子
とした点に特徴がある。In order to achieve the above object, one of the mass flow sensors according to the present invention is erected in an inverted U-shape on a main body block of a mass flow meter or a mass flow controller, and a fluid is provided inside. The first thermosensitive resistor and the second thermosensitive resistor are wound around one vertical portion of the flowing thin tube while being insulated from each other, and the third thermosensitive resistor and the fourth thermosensitive resistor are insulated from each other on the other vertical portion. The first heat-sensitive resistor and the third heat-sensitive resistor are connected in series, and the second heat-sensitive resistor and the fourth heat-sensitive resistor are connected in series while being wound in this state. It is characterized in that it is a constituent element.
【００１１】また、本発明に係る質量流量センサの他の
一つは、マスフローメータまたはマスフローコントロー
ラの本体ブロックに逆Ｕ字状に立設され、内部に流体が
流れる細管における一つの垂直部分に第１感熱抵抗体と
第２感熱抵抗体とを互いに絶縁した状態で巻設し、他の
垂直部分に第３感熱抵抗体と第４感熱抵抗体とを互いに
絶縁した状態で巻設すると共に、第１感熱抵抗体と第２
感熱抵抗体とをそれぞれ第１ブリッジ回路の構成素子と
する一方、第３感熱抵抗体と第４感熱抵抗体とをそれぞ
れ第１ブリッジ回路と並列に設けられる第２ブリッジ回
路の構成素子とした点に特徴がある。Another one of the mass flow sensors according to the present invention is an upright U-shape erected on a main body block of a mass flow meter or a mass flow controller, and a first vertical portion of a thin tube in which a fluid flows therein. The first heat sensitive resistor and the second heat sensitive resistor are wound in a state of being insulated from each other, and the third heat sensitive resistor and the fourth heat sensitive resistor are wound in a state of being insulated from each other in another vertical portion. 1 Thermal resistor and 2nd
The thermosensitive resistor is a constituent element of the first bridge circuit, while the third thermosensitive resistor and the fourth thermosensitive resistor are constituent elements of a second bridge circuit provided in parallel with the first bridge circuit. Is characterized by.
【００１２】[0012]
【作用】上記いずれの質量流量センサにおいても、熱対
流が発生せず、マスフローメータまたはマスフローコン
トローラの取付け姿勢に起因するゼロ点シフトがなくな
り、従って、質量流量センサの姿勢の如何に拘らず流体
の質量流量を精度よく検出できる。In any of the mass flow rate sensors described above, thermal convection does not occur, and the zero point shift caused by the mounting posture of the mass flow meter or mass flow controller is eliminated. The mass flow rate can be detected accurately.
【００１３】[0013]
【実施例】以下、本発明の実施例を、図面に基づいて説
明する。Embodiments of the present invention will be described below with reference to the drawings.
【００１４】図１は、本発明の一実施例に係る質量流量
センサ２０を示すもので、この図において、１３ｂ，１
３ｃは逆Ｕ字状の細管１３の水平部分１３ａの両側の垂
直部分で、流体流入側の垂直部分１３ａに第１感熱抵抗
体２１と第２感熱抵抗体２２とが互いに絶縁された状態
で巻設されており、流体流出側の垂直部分１３ｂに第３
感熱抵抗体２３と第４感熱抵抗体２４とが互いに絶縁さ
れた状態で巻設されている。すなわち、図６に示した従
来の質量流量センサ１２においては、逆Ｕ字状の細管１
３の中央水平部分１３ａに２つの感熱抵抗体１４，１５
を巻設していたのであるが、この実施例の質量流量セン
サ２０においては、細管１３の垂直部分１３ｂ，１３ｃ
にそれぞれ２つの感熱抵抗体２１，２２，２３，２４を
巻設している。なお、これらの感熱抵抗体２１〜２４
は、感熱特性が等しいものが用いられることはいうまで
もない。FIG. 1 shows a mass flow sensor 20 according to an embodiment of the present invention.
Reference numeral 3c designates vertical portions on both sides of the horizontal portion 13a of the inverted U-shaped thin tube 13, and the first heat-sensitive resistor 21 and the second heat-sensitive resistor 22 are wound around the vertical portion 13a on the fluid inflow side while being insulated from each other. Is installed in the vertical portion 13b on the fluid outflow side,
The heat sensitive resistor 23 and the fourth heat sensitive resistor 24 are wound in a state of being insulated from each other. That is, in the conventional mass flow sensor 12 shown in FIG. 6, the inverted U-shaped thin tube 1 is used.
In the central horizontal portion 13a of the three
However, in the mass flow sensor 20 of this embodiment, the vertical portions 13b and 13c of the thin tube 13 are wound.
Two heat-sensitive resistors 21, 22, 23, and 24 are wound around each. In addition, these thermal resistors 21 to 24
Needless to say, those having the same heat-sensitive characteristics are used.
【００１５】そして、前記感熱抵抗体２１〜２４は、第
１感熱抵抗体２１と第３感熱抵抗体２３とが直列接続さ
れ、第２感熱抵抗体２２と第４感熱抵抗体２４とが直列
接続され、図２に示すように、ブリッジ抵抗２５，２６
と共にブリッジ回路２７を形成している。そして、図２
において、２８，２９，３０，３１はブリッジ回路２７
における隣接する辺と辺との接続点で、接続点２８には
定電流源３２が接続され、接続点２８と対角上にある接
続点３０は接地され、接続点２９，３１が増幅回路３３
に接続されている。そして、ブリッジ回路２７の出力
は、出力端子３３ａ，３３ｂの間に出力される。In the heat sensitive resistors 21 to 24, the first heat sensitive resistor 21 and the third heat sensitive resistor 23 are connected in series, and the second heat sensitive resistor 22 and the fourth heat sensitive resistor 24 are connected in series. As shown in FIG. 2, the bridge resistors 25, 26
Together with this, a bridge circuit 27 is formed. And FIG.
28, 29, 30, and 31 are bridge circuits 27
A constant current source 32 is connected to the connection point 28 at a connection point between adjacent sides of the connection point 28, a connection point 30 diagonally connected to the connection point 28 is grounded, and connection points 29 and 31 are connected to an amplifier circuit 33.
It is connected to the. The output of the bridge circuit 27 is output between the output terminals 33a and 33b.
【００１６】上述のように構成された質量流量センサ２
０における姿勢の傾斜影響を調べるため、次のような実
験を行った。すなわち、細管１３として外径が０．６ｍ
ｍ、内径が０．４ｍｍのキャピラリを用い、試験ガスと
して傾斜影響が顕著に表れるＳＦ6 ガスを用い、これを
細管１３内に１〜３ｋｇｆ／ｃｍ2 Ｇで封入し、定電流
源３２によってブリッジ回路２７に一定の電流を流して
各感熱抵抗体２１〜２４の温度が例えば１００℃になる
ようにした。Mass flow sensor 2 constructed as described above
The following experiment was conducted in order to investigate the influence of the posture inclination at 0. That is, the outer diameter of the thin tube 13 is 0.6 m.
m, an inner diameter of 0.4 mm, a test gas of SF 6 gas having a remarkable tilt effect, and sealed in a thin tube 13 at 1 to 3 kgf / cm 2 G and bridged by a constant current source 32. A constant current is applied to the circuit 27 so that the temperature of each of the heat sensitive resistors 21 to 24 becomes 100 ° C., for example.
【００１７】前記質量流量センサ２０を、図３（Ａ）に
示すように、細管１３の中央部分１３ａが水平となる状
態、すなわち、水平姿勢となるように取り付け、試験ガ
スを封入した状態（ゼロ状態）においては、細管１３の
左右の垂直部分１３ｂ，１３ｃがほぼ同じ程度に加熱さ
れるので、図中に示す熱量Ｑ1 ，Ｑ2 が互いに等しくな
り、その結果、熱対流が生ずることがなくなる。また、
図３（Ｂ）に示すように、細管１３の中央部分１３ａが
垂直となる状態、すなわち、質量流量センサ２０を垂直
姿勢となるように取り付け、試験ガスを封入した状態
（ゼロ状態）においては、矢印方向への流体の移動がな
いので、熱対流は殆ど生じず、従って、水平姿勢と同様
に、熱対流の影響は殆どない。なお、図３（Ａ），
（Ｂ）において、３４は細管１３の開口端側に接続され
る閉ループ形成用の補助キャピラリである。As shown in FIG. 3 (A), the mass flow sensor 20 is mounted such that the central portion 13a of the thin tube 13 is horizontal, that is, the mass flow sensor 20 is in a horizontal posture and the test gas is sealed (zero). (State), since the left and right vertical portions 13b and 13c of the thin tube 13 are heated to substantially the same degree, the heat amounts Q 1 and Q 2 shown in the figure are equal to each other, and as a result, heat convection does not occur. . Also,
As shown in FIG. 3B, in a state where the central portion 13a of the thin tube 13 is vertical, that is, in a state where the mass flow sensor 20 is attached in a vertical posture and a test gas is sealed (zero state), Since there is no movement of the fluid in the direction of the arrow, there is almost no thermal convection, and therefore there is almost no effect of thermal convection as in the horizontal attitude. In addition, FIG.
In (B), 34 is an auxiliary capillary for forming a closed loop, which is connected to the open end side of the thin tube 13.
【００１８】そして、補助キャピラリ３４を外して、質
量流量センサ２０に前記試験ガスを流したときには、感
熱抵抗体と従来の２倍の４個であるので、初段出力とし
ては、センサ単品で得られる初段出力の和が得られる。
従って、本発明の質量流量センサ２０においては、従来
の質量流量センサ１２に比べて約２倍の感度（スパン初
段感度）で測定することができる。When the test gas is flown through the mass flow sensor 20 with the auxiliary capillary 34 removed, the number of heat-sensitive resistors and the conventional four are four, so the first stage output can be obtained as a single sensor. The sum of the first stage output is obtained.
Therefore, in the mass flow rate sensor 20 of the present invention, it is possible to measure with a sensitivity (span first stage sensitivity) that is about twice as high as that of the conventional mass flow rate sensor 12.
【００１９】図４は、図６に示した従来の質量流量セン
サ１２と前記本発明の質量流量センサ２０の細管１３に
それぞれＳＦ6 ガスを試験ガスとして充填し、その十点
圧力を変化させたときにおけるフルスケール値（ＦＳ）
換算変動値と試験ガスの充填圧力との関係を示すグラフ
で、この図において、実線Ａ、点線Ｂはそれぞれ、従来
の質量流量センサ１２の特性曲線、本発明の質量流量セ
ンサ２０の特性曲線である。このグラフから、本発明の
質量流量センサ２０は、前述したようにスパン初段感度
が増加しているので、初段出力値の変動が、フルスケー
ル換算値において、従来の質量流量センサ１２のそれの
約１／７に低減され、それだけ測定精度が向上している
ことが判る。In FIG. 4, SF 6 gas is filled as a test gas in the thin tubes 13 of the conventional mass flow sensor 12 and the mass flow sensor 20 of the present invention shown in FIG. 6, and the ten-point pressure is changed. Full scale value (FS) at time
In the graph showing the relationship between the conversion fluctuation value and the filling pressure of the test gas, the solid line A and the dotted line B are the characteristic curve of the conventional mass flow sensor 12 and the characteristic curve of the mass flow sensor 20 of the present invention, respectively. is there. From this graph, in the mass flow sensor 20 of the present invention, since the span first stage sensitivity is increased as described above, the fluctuation of the first stage output value is about the full scale conversion value of that of the conventional mass flow sensor 12. It can be seen that the measurement accuracy is improved by being reduced to 1/7.
【００２０】本発明は、上述の実施例に限られるもので
はなく、図５に示すように、第１感熱抵抗体２１と第２
感熱抵抗体２２とをそれぞれ第１ブリッジ回路４１の構
成素子とする一方、第３感熱抵抗体２３と第４感熱抵抗
体２４とをそれぞれ第１ブリッジ回路４１と並列に設け
られる第２ブリッジ回路４２の構成素子となるようにし
てもよい。なお、この図において、４１〜４６はブリッ
ジ抵抗、４７，４８は定電流源、４９，５０はブリッジ
回路４１，４２の出力をそれぞれ増幅する回路、５１は
増幅回路４９，５０の出力を加算する回路である。The present invention is not limited to the above embodiment, but as shown in FIG.
The heat sensitive resistor 22 is used as a constituent element of the first bridge circuit 41, while the third heat sensitive resistor 23 and the fourth heat sensitive resistor 24 are respectively provided in parallel with the first bridge circuit 41 and the second bridge circuit 42. It may be configured as the constituent element. In this figure, 41 to 46 are bridge resistors, 47 and 48 are constant current sources, 49 and 50 are circuits for amplifying the outputs of the bridge circuits 41 and 42, and 51 is a sum of the outputs of the amplifier circuits 49 and 50. Circuit.
【００２１】このように構成した実施例においても、前
述の実施例と同様の作用効果を奏するので、その詳細な
説明は省略する。The embodiment constructed in this way also has the same effects as the above-mentioned embodiment, so a detailed description thereof will be omitted.
【００２２】[0022]
【発明の効果】以上説明したように、本発明によれば、
質量流量センサにおける熱対流が発生せず、マスフロー
メータまたはマスフローコントローラの取付け姿勢に起
因するゼロ点シフトがなくなり、従って、質量流量セン
サの姿勢の如何に拘らず流体の質量流量を精度よく検出
できる。As described above, according to the present invention,
No thermal convection is generated in the mass flow sensor, and the zero point shift caused by the mounting posture of the mass flow meter or the mass flow controller is eliminated. Therefore, the mass flow rate of the fluid can be accurately detected regardless of the posture of the mass flow sensor.
【図１】本発明に係る質量流量センサの一構成例を示す
図である。FIG. 1 is a diagram showing a configuration example of a mass flow sensor according to the present invention.
【図２】前記質量流量センサを組み込んだ電気回路の一
例を示す図である。FIG. 2 is a diagram showing an example of an electric circuit incorporating the mass flow sensor.
【図３】本発明の動作説明図である。FIG. 3 is an operation explanatory diagram of the present invention.
【図４】従来の質量流量センサと本発明の質量流量セン
サの特性を示すグラフである。FIG. 4 is a graph showing characteristics of a conventional mass flow sensor and a mass flow sensor of the present invention.
【図５】本発明に係る質量流量センサを組み込んだ電気
回路の他の例を示す図である。FIG. 5 is a diagram showing another example of an electric circuit incorporating the mass flow rate sensor according to the present invention.
【図６】従来の質量流量センサを組み込んだマスフロー
メータを示す図である。FIG. 6 is a diagram showing a mass flow meter incorporating a conventional mass flow sensor.
【図７】従来の質量流量センサの欠点を説明するための
図である。FIG. 7 is a diagram for explaining a defect of a conventional mass flow rate sensor.
１…本体ブロック、１３…細管、１３ｂ，１３ｃ…垂直
部分、２０…質量流量センサ、２１…第１感熱抵抗体、
２２…第２感熱抵抗体、２３…第３感熱抵抗体、２４…
第４感熱抵抗体、２７…ブリッジ回路、４１…第１ブリ
ッジ回路、４２…第２ブリッジ回路。DESCRIPTION OF SYMBOLS 1 ... Main body block, 13 ... Capillary tube, 13b, 13c ... Vertical part, 20 ... Mass flow sensor, 21 ... 1st thermosensitive resistor,
22 ... 2nd thermosensitive resistor, 23 ... 3rd thermosensitive resistor, 24 ...
Fourth thermal resistor, 27 ... Bridge circuit, 41 ... First bridge circuit, 42 ... Second bridge circuit.
Claims (2)
トローラの本体ブロックに逆Ｕ字状に立設され、内部に
流体が流れる細管における一つの垂直部分に第１感熱抵
抗体と第２感熱抵抗体とを互いに絶縁した状態で巻設
し、他の垂直部分に第３感熱抵抗体と第４感熱抵抗体と
を互いに絶縁した状態で巻設すると共に、第１感熱抵抗
体と第３感熱抵抗体とを直列接続したものと、第２感熱
抵抗体と第４感熱抵抗体とを直列接続したものとをそれ
ぞれブリッジ回路の構成素子としたことを特徴とする質
量流量センサ。1. A first heat-sensitive resistor and a second heat-sensitive resistor are insulated from each other in one vertical portion of a thin tube in which a fluid flows inside, which is installed upright in a body block of a mass flow meter or a mass flow controller. And a third heat sensitive resistor and a fourth heat sensitive resistor are wound on the other vertical portion while being insulated from each other, and the first heat sensitive resistor and the third heat sensitive resistor are connected in series. The mass flow rate sensor, wherein the second heat sensitive resistor and the fourth heat sensitive resistor connected in series are used as constituent elements of a bridge circuit.
トローラの本体ブロックに逆Ｕ字状に立設され、内部に
流体が流れる細管における一つの垂直部分に第１感熱抵
抗体と第２感熱抵抗体とを互いに絶縁した状態で巻設
し、他の垂直部分に第３感熱抵抗体と第４感熱抵抗体と
を互いに絶縁した状態で巻設すると共に、第１感熱抵抗
体と第２感熱抵抗体とをそれぞれ第１ブリッジ回路の構
成素子とする一方、第３感熱抵抗体と第４感熱抵抗体と
をそれぞれ第１ブリッジ回路と並列に設けられる第２ブ
リッジ回路の構成素子としたことを特徴とする質量流量
センサ。2. A first heat-sensitive resistor and a second heat-sensitive resistor are insulated from each other in one vertical portion of a thin tube in which a fluid flows inside, which is installed upright in a main body block of a mass flow meter or a mass flow controller. And a third thermal resistor and a fourth thermal resistor are insulated from each other on the other vertical portions, while the first thermal resistor and the second thermal resistor are respectively wound. A mass flow sensor, wherein the third heat sensitive resistor and the fourth heat sensitive resistor are each a constituent element of a second bridge circuit provided in parallel with the first bridge circuit. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19404093A JP3266707B2 (en) | 1993-07-10 | 1993-07-10 | Mass flow sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19404093A JP3266707B2 (en) | 1993-07-10 | 1993-07-10 | Mass flow sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0727582A true JPH0727582A (en) | 1995-01-27 |
| JP3266707B2 JP3266707B2 (en) | 2002-03-18 |
Family
ID=16317942
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19404093A Expired - Fee Related JP3266707B2 (en) | 1993-07-10 | 1993-07-10 | Mass flow sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3266707B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001304934A (en) * | 2000-03-30 | 2001-10-31 | Berkin Bv | Mass flowmeter |
| JP2005172445A (en) * | 2003-12-08 | 2005-06-30 | Osaka Prefecture | Flow sensor |
| JP2007127466A (en) * | 2005-11-02 | 2007-05-24 | Nippon M K S Kk | Flow sensor |
| JP2007322207A (en) * | 2006-05-31 | 2007-12-13 | Yokogawa Electric Corp | Magnetic oxygen measuring method and magnetic oxygen meter |
| JP2009516853A (en) * | 2005-11-22 | 2009-04-23 | エム ケー エス インストルメンツ インコーポレーテッド | Vertically mounted mass flow sensor |
| US7971480B2 (en) | 2008-10-13 | 2011-07-05 | Hitachi Metals, Ltd. | Mass flow controller having a first pair of thermal sensing elements opposing a second pair of thermal sensing elements |
| KR101335545B1 (en) * | 2012-07-09 | 2013-12-02 | 엠케이프리시젼 주식회사 | Mass flow measurement sensor |
| JP2016217814A (en) * | 2015-05-18 | 2016-12-22 | アズビル株式会社 | Thermal type flow meter and inclination error improvement method thereof |
-
1993
- 1993-07-10 JP JP19404093A patent/JP3266707B2/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001304934A (en) * | 2000-03-30 | 2001-10-31 | Berkin Bv | Mass flowmeter |
| JP2005172445A (en) * | 2003-12-08 | 2005-06-30 | Osaka Prefecture | Flow sensor |
| JP2007127466A (en) * | 2005-11-02 | 2007-05-24 | Nippon M K S Kk | Flow sensor |
| JP2009516853A (en) * | 2005-11-22 | 2009-04-23 | エム ケー エス インストルメンツ インコーポレーテッド | Vertically mounted mass flow sensor |
| JP2007322207A (en) * | 2006-05-31 | 2007-12-13 | Yokogawa Electric Corp | Magnetic oxygen measuring method and magnetic oxygen meter |
| US7971480B2 (en) | 2008-10-13 | 2011-07-05 | Hitachi Metals, Ltd. | Mass flow controller having a first pair of thermal sensing elements opposing a second pair of thermal sensing elements |
| KR101335545B1 (en) * | 2012-07-09 | 2013-12-02 | 엠케이프리시젼 주식회사 | Mass flow measurement sensor |
| JP2016217814A (en) * | 2015-05-18 | 2016-12-22 | アズビル株式会社 | Thermal type flow meter and inclination error improvement method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3266707B2 (en) | 2002-03-18 |
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