JP2015025760A - Conductance and inductivity measurement equipment for fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide conductance and inductivity measurement equipment for fluid which does not cause increase of flow resistance in a duct.SOLUTION: The conductance and inductivity measurement equipment for fluid comprises: a first electrode body E1 having a circular electrode hole h; a second electrode body E2 having a circular electrode hole h; and an electrode holder 20 for holding the first electrode body E1 and the second electrode body E2 with an interval in a standing state. On the electrode holder 20, a passage hole 21a being coincident with the circular electrode holes h of the first electrode body E1 and the second electrode body E2 in a state that the circular electrode holes h face each other is formed in a penetrated state.

Description

本発明は、流体の導電率（電気伝導率）と誘電率の双方を測定可能な流体の導電率兼誘電率測定器に関し、特に燃料電池発電システムの管路において純水の汚れを検出するのに好適な導電率測定器と、その純水中に含まれる炭酸ガス等の気泡（水枯れ）を検出するのに好適な誘電率測定器に関する。   The present invention relates to a fluid conductivity / dielectric constant measuring device capable of measuring both the electrical conductivity (electrical conductivity) and the dielectric constant of a fluid, and more particularly to detecting contamination of pure water in a conduit of a fuel cell power generation system. And a dielectric constant measuring apparatus suitable for detecting bubbles (water withering) such as carbon dioxide contained in the pure water.

特許文献１に開示された水位計付き導電率計は、燃料電池発電システムにおける水槽内の底部に浸漬された送信電極と、それよりも浅部に浸漬された受信電極と、５００Ｈｚの導電率用周波数信号を発信する導電率用発信回路から上記送信電極までの間に設けられた第１アナログスイッチと、１００ＫＨｚの水位（誘電率）用周波数信号を発信する水位用発信回路から上記送信電極までの間に設けられた第２アナログスイッチと、上記受信電極から導電率測定回路までの間に設けられた第３アナログスイッチと、上記受信電極から水位（誘電率）測定回路までの間に設けられた第４アナログスイッチと、第１及び第３アナログスイッチと第２及び第４アナログスイッチとを排他的にオン／オフ制御するための１００Ｈｚのスイッチ切換用周波数信号を発信するスイッチ切換用発信回路とを有している。   A conductivity meter with a water level meter disclosed in Patent Document 1 is a transmitter electrode immersed in the bottom of a water tank in a fuel cell power generation system, a receiver electrode immersed in a shallower portion thereof, and a conductivity of 500 Hz. A first analog switch provided between the conductivity transmission circuit for transmitting a frequency signal and the transmission electrode, and a water level transmission circuit for transmitting a water level (dielectric constant) frequency signal of 100 KHz to the transmission electrode. A second analog switch provided in between, a third analog switch provided between the reception electrode and the conductivity measurement circuit, and a connection between the reception electrode and the water level (dielectric constant) measurement circuit. 100 Hz switching frequency for exclusive on / off control of the fourth analog switch, the first and third analog switches, and the second and fourth analog switches And a switch switching transmission circuit for transmitting a signal.

低周波数の５００Ｈｚの導電率用周波数信号を用いた導電率測定と高周波数の１００ＫＨｚの水位（誘電率）用周波数信号を用いた水位（誘電率）測定とをスイッチ切換用周波数信号により５ｍｓの時間分割で交互に実測できるため、水槽内の純水の汚れを検出するための導電率測定と受信電極が水面上に露出する水位（水枯れ）を検出するための誘電率測定の双方が可能となっている。   Conductivity measurement using a low frequency frequency signal for 500 Hz conductivity and high frequency 100 KHz water level (dielectric constant) frequency measurement using a frequency signal for switch switching frequency signal for 5 ms. Since measurement can be performed alternately by dividing, both conductivity measurement for detecting contamination of pure water in the water tank and dielectric constant measurement for detecting the water level (water draining) where the receiving electrode is exposed on the water surface are possible. It has become.

特開２０１３−１０４７５５（図１〜図４）JP2013-104755A (FIGS. 1 to 4)

ところで、この水位計付き導電率計を水槽内ではなく例えば水平姿勢の管路を流れる純水の導電率測定と気泡（水枯れ）検出とに利用しようとする場合、送信電極と受信電極を管路の横断方向に挿入した状態においては、両電極が純水の流動を妨げて流速を落とす流動抵抗体となって観測対象を徒に乱してしまう。特に、気泡（水枯れ）検出の誘電率測定においては両電極間の対向面積を増やして電気容量を大きく確保する必要があるため、流動抵抗の過大化を招く。また、管路での水枯れの検出では、水槽内のように受信電極が水面上に露出するのではなく、気泡が管路を通過することにより水枯れが始まるため、純水中の気泡を淀ますことなく検出できるものでなければならない。   By the way, when this conductivity meter with a water level meter is used not in the water tank but for measuring the conductivity of pure water flowing through a horizontal channel, for example, and detecting bubbles (water withering), the transmitter electrode and the receiver electrode are connected to the tube. In the state of being inserted in the transverse direction of the road, both electrodes become a flow resistor that impedes the flow of pure water and reduces the flow velocity, and disturbs the observation target. In particular, in the dielectric constant measurement for detecting bubbles (withering water), it is necessary to increase the facing area between both electrodes to ensure a large electric capacity, which leads to excessive flow resistance. In addition, in the detection of water withering in the pipeline, the receiving electrode is not exposed on the surface of the water as in the water tank, but the water begins to wither when the bubbles pass through the pipeline, so bubbles in the pure water are removed.も の It must be able to be detected without hesitation.

そこで、本発明の第１の課題は、上記問題点を解決するものであり、管路の流動抵抗の増大を招かずに済む流体の導電率兼誘電率測定器を提供することにある。また、本発明の第２の課題は、管路を流れる流体中の気泡を淀ますことなく検出可能な流体の導電率兼誘電率測定器を提供することにある。   Accordingly, a first object of the present invention is to solve the above-mentioned problems and to provide a fluid conductivity / dielectric constant measuring device that does not increase the flow resistance of a pipe. A second object of the present invention is to provide a fluid conductivity / dielectric constant measuring device capable of detecting a bubble in a fluid flowing through a pipeline without damaging it.

本発明に係る流体の導電率兼誘電率測定器は、第１電極孔を持つ第１電極体と、第２電極孔を持つ第２電極体と、第１電極体及び第２電極体を隔てて保持する電極ホルダとを備え、この電極ホルダにおいて第１電極孔と第２電極孔とが相向き合う状態でこれらに合致する流路孔が貫通形成されて成ることを特徴とする。   The fluid conductivity / dielectric constant measuring device according to the present invention includes a first electrode body having a first electrode hole, a second electrode body having a second electrode hole, and the first electrode body and the second electrode body. The electrode holder is characterized in that a channel hole that matches the first electrode hole and the second electrode hole is formed through the electrode holder in a state where the first electrode hole and the second electrode hole face each other.

かかる構成においては、第１電極孔と第２電極孔とが相向き合う第１電極孔の孔縁と第２電極孔の孔縁とが実質的に相対向する電極対となり、流体は一方の電極孔内から流路孔内を介して他方の電極孔内を乱されずに流下し、流動抵抗の増大させずに済み、また流体内に含まれる気泡などが電極孔や流路孔内で淀まず、気泡などの通過の際の誤検出が防げる。   In such a configuration, the hole edge of the first electrode hole and the hole edge of the second electrode hole in which the first electrode hole and the second electrode hole face each other are substantially opposed to each other, and the fluid is one electrode. The other electrode hole flows from the hole through the channel hole without being disturbed, and the flow resistance is not increased, and bubbles contained in the fluid are trapped in the electrode hole and the channel hole. First of all, it is possible to prevent erroneous detection when air bubbles pass through.

電極ホルダは第１電極体及び第２電極体をインサートとする樹脂成形品でも構わないが、電極体の交換や清掃などにおいては、第１電極体及び第２電極体とは別体のものとするのが望ましい。即ち、電極ホルダは、流路孔に直交して第１電極体を差し込み保持可能な第１電極収納穴と、流路孔に直交して第２電極体を差し込み保持可能な第２電極収納穴を備えて成ることが望ましい。   The electrode holder may be a resin molded product using the first electrode body and the second electrode body as inserts. However, in replacement or cleaning of the electrode body, the electrode holder is separate from the first electrode body and the second electrode body. It is desirable to do. That is, the electrode holder includes a first electrode housing hole that can be inserted and held perpendicular to the flow path hole, and a second electrode housing hole that can be inserted and held perpendicular to the flow path hole. It is desirable to comprise.

この流体の導電率兼誘電率測定器においては、各電極体の端子ピン部に接続可能な回路基板を組み込んだ測定ケースを備えており、この測定ケースは、電極ホルダを差し込み保持可能なホルダ収納穴と、このホルダ収納穴に連通して流路孔の一方の開口に一端側が連絡すると共に他端側に流入側接手部を備える流入孔と、ホルダ収納穴に連通して流路孔の他方の開口に一端側が連絡すると共に他端側に流出側接手部を備える流出孔とを有する。かような測定ケースを用いれば、例えば燃料電池発電システムの管路において流入管を流入側接手部に接続すると共に流出管を流出側接手部に接続する簡単な作業だけで、純水の汚れと気泡（水枯れ）の検出を行うことができる。   This fluid conductivity / dielectric constant measuring instrument has a measurement case in which a circuit board that can be connected to the terminal pin portion of each electrode body is incorporated, and this measurement case contains a holder in which an electrode holder can be inserted and held. A hole, an inflow hole having one end connected to one opening of the flow path hole and communicating with the one opening of the flow path hole and having an inflow side joint on the other end, and the other of the flow path holes communicating with the holder storage hole. One end side communicates with the opening, and the other end side has an outflow hole having an outflow side joint portion. By using such a measurement case, for example, in the pipeline of a fuel cell power generation system, it is possible to remove the contamination of pure water by simply connecting the inflow pipe to the inflow side joint and the outflow pipe to the outflow side joint. Bubbles (withered) can be detected.

ここで、流路孔の断面積は流入孔及び流出孔の断面積に比して狭くなっていることが望ましい。流入孔及び流出孔内の流体の流速が低速であっても、流路孔内の流速を高めることができるので、気泡や異物が電極孔内や流路孔内面に付着し難く、誤検出を防げる。   Here, it is desirable that the cross-sectional area of the flow path hole is narrower than the cross-sectional areas of the inflow hole and the outflow hole. Even if the flow velocity of the fluid in the inflow hole and outflow hole is low, the flow velocity in the flow path hole can be increased. I can prevent it.

更に、各電極体は、直径方向に電極孔を持つ有孔円柱部と、この有孔円柱部から端子ピン部側に位置して有孔円柱部との間にＯリング装着用縮径部を画成する鍔部とを一体的に有し、Ｏリング縮径部にＯリングが装着されて成る場合、被測定流体の電極収納穴内での漏洩を防止できる。また、電極孔が円柱部の直径方向に形成されているため、円柱部を軸回転させて電極孔の向きを変えることで、電極孔と流路孔との向き合い整合を図ることができる。   Furthermore, each electrode body has a perforated cylindrical portion having an electrode hole in the diameter direction, and a reduced diameter portion for mounting an O-ring between the perforated cylindrical portion and the perforated cylindrical portion located on the terminal pin portion side. When the O-ring is mounted on the O-ring diameter-reduced portion, the leakage fluid can be prevented from leaking in the electrode housing hole. Further, since the electrode holes are formed in the diameter direction of the cylindrical portion, the orientation matching between the electrode holes and the flow path holes can be achieved by rotating the cylindrical portion to change the direction of the electrode holes.

また、各電極体は、端子ピン部と鍔部との間に回し位置決め用見当部を一体的に有することが望ましい。電極体を電極収納穴に差し込んだ際、電極孔と流路孔との向き合い整合が視認できないときでも、回し位置決め用見当部の位置合わせだけで向き合い整合を図ることができる。   Further, it is desirable that each electrode body integrally has a positioning register for turning between the terminal pin portion and the collar portion. When the electrode body is inserted into the electrode housing hole, even if the orientation matching between the electrode hole and the flow path hole cannot be visually recognized, the orientation matching can be achieved only by the positioning of the rotating positioning register.

流体内にある第１電極孔の孔縁と第２電極孔の孔縁とが向い合う電極対としては不要部分の静電容量を制限するのが理想的ではあるが、事実上、電極孔以外の対向面積部分が寄生容量となっている。そこで、各電極体は、鍔部と回し位置決め用見当部と間に肉盗みの縮径部を一体的に有することが望ましい。肉盗みの縮径部同士により対向面積が減少すると共に対向距離が増加する分、寄生容量を抑制でき、誘電率測定の分解能が向上する。   Although it is ideal to limit the capacitance of unnecessary portions as the electrode pair in which the hole edge of the first electrode hole and the hole edge of the second electrode hole face each other in the fluid, in fact, other than the electrode hole The opposite area portion is a parasitic capacitance. Therefore, it is desirable that each electrode body integrally has a reduced diameter portion for stealing the meat between the collar portion and the rotating positioning register portion. As the opposing area decreases and the opposing distance increases due to the reduced diameter portions of the stealing meat, the parasitic capacitance can be suppressed and the resolution of permittivity measurement is improved.

そして、この流体の導電率兼誘電率測定器において、第１の周波数信号を発信する導電率用発信回路の出力端と第１電極体との間に介在する第１のスイッチと、第１の周波数信号によりも高い第２の周波数信号を発信する誘電率用発信回路の出力端と第１電極体との間に介在する第２のスイッチと、第２電極体と導電率測定回路の入力端との間に介在する第３のスイッチと、第２電極体と誘電率測定回路の入力端との間に介在する第４のスイッチとを有し、第１の周波数信号よりも低いスイッチ切換用周波数信号で第１及び第３のスイッチと第２及び第４のスイッチとを排他的にオン／オフ制御することを特徴とする。第１及び第３のスイッチのオン期間においては、第２及び第４のスイッチのオフ期間であり、第１の周波数信号の発信による導電率測定だけが可能となり、他方、第２及び第４のスイッチのオン期間においては、第１及び第３のスイッチのオフ期間であり、第２の周波数信号の発信による誘電率測定が可能となり、クロストークが起らず、リアルタイムで時間分割の交互測定を実現できる。   In the fluid conductivity / dielectric constant measuring device, a first switch interposed between the output terminal of the conductivity transmission circuit for transmitting the first frequency signal and the first electrode body, A second switch interposed between the output terminal of the transmission circuit for permittivity that transmits a second frequency signal higher than the frequency signal and the first electrode body; and an input terminal of the second electrode body and the conductivity measurement circuit And a fourth switch interposed between the second electrode body and the input terminal of the dielectric constant measuring circuit, and for switching a switch lower than the first frequency signal. The first and third switches and the second and fourth switches are exclusively turned on / off by the frequency signal. The ON period of the first and third switches is the OFF period of the second and fourth switches, and only the conductivity measurement by the transmission of the first frequency signal is possible, while the second and fourth switches The on-period of the switch is the off-period of the first and third switches, and permittivity measurement can be performed by transmitting the second frequency signal, crosstalk does not occur, and time-division alternating measurement is performed in real time. realizable.

なお、この回路構成においては、上記のような電極孔を持つ電極体を用いずに、従来一般の電極体を用いても構わない。   In this circuit configuration, a conventional general electrode body may be used instead of the electrode body having the electrode holes as described above.

そして、上記回路構成においては特に誘電率測定回路に特徴を有する。即ち、誘電率測定回路としては、第４のスイッチから入来する信号電流を信号電圧に変換する電流／電圧変換手段と、定電圧源に制限抵抗を介してプルアップされて成る充放電用コンデンサと、信号電圧を第１の閾値電圧と比較してこれを超えるときはオン状態となって充放電用コンデンサを瞬間放電せしめる放電制御手段と、第４のスイッチのオン期間での充放電用コンデンサの充電電圧を第４のスイッチのオフ期間終期での充放電用コンデンサの充電電圧値よりも高い第２の閾値電圧と比較してこれを超えるときは異常信号を出力する比較手段とを有することを特徴とする。制限抵抗を介して定電圧源にプルアップされて成る充放電コンデンサを用い、これに対して信号電圧の入来時に放電制御することにより、事実上、充放電コンデンサに対する充電時間の長短比較を以て水枯れを高精度に検出できる。   The circuit configuration is particularly characterized by a dielectric constant measurement circuit. That is, the dielectric constant measuring circuit includes a current / voltage converting means for converting a signal current coming from the fourth switch into a signal voltage, and a charging / discharging capacitor that is pulled up to a constant voltage source through a limiting resistor. A discharge control means for turning on and instantaneously discharging the charge / discharge capacitor when the signal voltage exceeds the first threshold voltage and exceeds this, and the charge / discharge capacitor during the ON period of the fourth switch And comparing means for outputting an abnormal signal when the charging voltage exceeds the second threshold voltage higher than the charging voltage value of the charging / discharging capacitor at the end of the OFF period of the fourth switch. It is characterized by. By using a charge / discharge capacitor that is pulled up to a constant voltage source through a limiting resistor and controlling the discharge when a signal voltage is received, the charge / discharge capacitor is effectively compared with the charge time of the charge / discharge capacitor. Withering can be detected with high accuracy.

本発明によれば、管路の流動抵抗の増大を招かずに済み、また管路を流れる流体中の気泡を検出可能な流体の導電率兼誘電率測定器を提供できる。   According to the present invention, it is possible to provide a fluid conductivity / dielectric constant measuring device that does not increase the flow resistance of a pipeline and can detect bubbles in the fluid flowing through the pipeline.

本発明の実施例に係る流体の導電率兼誘電率測定器を示す縦断斜視図である。It is a vertical perspective view which shows the electrical conductivity and dielectric constant measuring device of the fluid which concerns on the Example of this invention. 同導電率兼誘電率測定器の組立斜視図である。It is an assembly perspective view of the electrical conductivity and dielectric constant measuring device. （Ａ）は同導電率兼誘電率測定器において用いる電極体を示す斜視図、（Ｂ）はＯリングを装着した電極体を示す斜視図、（Ｃ）は同導電率兼誘電率測定器において用いる電極ホルダを示す縦断斜視図である。(A) is a perspective view showing an electrode body used in the same conductivity and permittivity measuring device, (B) is a perspective view showing an electrode body equipped with an O-ring, and (C) is in the same conductivity and permittivity measuring device. It is a vertical perspective view which shows the electrode holder to be used. （Ａ）は同電極体の平面図、（Ｂ）は同電極体の正面図、（Ｃ）は同電極体の底面図、（Ｄ）は同電極体の左側面図である。(A) is a plan view of the electrode body, (B) is a front view of the electrode body, (C) is a bottom view of the electrode body, and (D) is a left side view of the electrode body. 同導電率兼誘電率測定器の電気的構成を示す回路ブロック図である。It is a circuit block diagram which shows the electrical structure of the same electrical conductivity and dielectric constant measuring device. （Ａ）は同導電率兼誘電率測定器において誘電率測定回路の詳細を示す回路図、（Ｂ）は同誘電率測定回路の動作を示すタイミングチャートである。(A) is a circuit diagram showing details of a dielectric constant measuring circuit in the same conductivity and dielectric constant measuring device, and (B) is a timing chart showing an operation of the dielectric constant measuring circuit.

次に、本発明の実施例を添付図面に基づいて説明する。先ず、本例の流体の導電率兼誘電率測定器の機械的構成は、測定ケース１０と、電極ホルダ２０と、同一の第１電極体Ｅ１及び第２電極体Ｅ２と、ホルダカバー３０と、回路基板４５とから成る。   Next, embodiments of the present invention will be described with reference to the accompanying drawings. First, the mechanical configuration of the fluid conductivity / dielectric constant measuring device of this example includes a measurement case 10, an electrode holder 20, the same first electrode body E1 and second electrode body E2, a holder cover 30, Circuit board 45.

測定ケース１０は樹脂成型品で、底板中央部分において電極ホルダ２０を差し込み保持可能な丸竪穴のホルダ収納穴１１と、底板の一方側においてホルダ収納穴１１に連通して流入側接手部（雌コネクタ）１２ａを備える流入孔１２と、底板の他方側においてホルダ収納穴１１に連通して流出側接手部（雄コネクタ）１３ａを備える流出孔１３とを備えている。   The measurement case 10 is a resin molded product. The holder housing hole 11 is a round hole that can hold the electrode holder 20 in the center portion of the bottom plate, and the inflow side joint portion (female connector) that communicates with the holder housing hole 11 on one side of the bottom plate. ) 12a provided with an inflow hole 12 and an outflow hole 13 provided with an outflow side joint (male connector) 13a in communication with the holder housing hole 11 on the other side of the bottom plate.

電極ホルダ２０は略円柱状の絶縁樹脂成形品で、直径方向に貫通する流路孔２１と、この流路孔２１に直交して第１電極体Ｅ１が差し込み保持可能な丸竪穴の第１電極収納穴２２と、流路孔２１に直交して第２電極体Ｅ２が差し込み保持可能な丸竪穴の第２電極収納穴２３とを備えている。流路孔２１の流入側及び流出側の開口縁はテーパー面Ｔとなっている。電極ホルダ２０の拡径部２４の段差にはＯリングＮが装着されている。   The electrode holder 20 is a substantially cylindrical insulating resin molded product, and includes a flow passage hole 21 penetrating in the diameter direction, and a first electrode having a round hole that is orthogonal to the flow passage hole 21 and into which the first electrode body E1 can be inserted and held. A storage hole 22 and a second electrode storage hole 23 that is orthogonal to the flow path hole 21 and can be inserted and held by the second electrode body E2 are provided. The opening edges on the inflow side and the outflow side of the flow path hole 21 are tapered surfaces T. An O-ring N is attached to the step of the enlarged diameter portion 24 of the electrode holder 20.

電極体Ｅ１（Ｅ２）は真直状導電性金属製で、直径方向に貫通した円形電極孔ｈを持つ有孔円柱部Ｕと、この有孔円柱部Ｕの上側に位置して有孔円柱部Ｕとの間にＯリング装着用縮径部Ｖを画成する鍔部Ｆと、この鍔部Ｆの上側で肉盗みの縮径部Ｓだけ離して位置する両Ｄカットの回し位置決め用見当部（マーカー）Ｗと、この回し位置決め用見当部Ｗの上側でカバー差し込み部Ｍだけ離して位置する端子ピン部Ｐとを一体的に備えている。Ｏリング装着用縮径部ＶにはＯリングＱが装着されている。   The electrode body E1 (E2) is made of a straight conductive metal, and has a perforated cylindrical portion U having a circular electrode hole h penetrating in the diameter direction, and a perforated cylindrical portion U located above the perforated cylindrical portion U. A flange portion F defining a reduced diameter portion V for mounting an O-ring, and a rotating positioning register portion of both D-cuts positioned above the flange portion F by a reduced diameter portion S for meat stealing ( A marker) W and a terminal pin portion P located on the upper side of the turning positioning register W by a cover insertion portion M are integrally provided. An O-ring Q is mounted on the reduced diameter portion V for mounting the O-ring.

ホルダカバー３０は、電極体Ｅ１（Ｅ２）のカバー差し込み部Ｍが嵌るカバー孔３１を有する。回路基板４５は、測定ケース１０の蓋板としても機能し、電極体Ｅ１（Ｅ２）の端子ピン部Ｐが嵌るスル―ホール４６を有する。   The holder cover 30 has a cover hole 31 into which the cover insertion portion M of the electrode body E1 (E2) is fitted. The circuit board 45 also functions as a cover plate of the measurement case 10 and has a through hole 46 into which the terminal pin portion P of the electrode body E1 (E2) is fitted.

第１電極体Ｅ１の円形電極孔ｈと第２電極体Ｅ２の円形電極孔ｈとが向い合った状態となっており、これらに合致する流路孔２１が貫通形成されている。そして、流路孔２１及び円形電極孔ｈの断面積は流入孔１２及び流出孔１３の断面積に比して狭くなっている。   The circular electrode hole h of the first electrode body E1 and the circular electrode hole h of the second electrode body E2 face each other, and a flow path hole 21 that matches these is formed through. The cross-sectional areas of the channel hole 21 and the circular electrode hole h are narrower than the cross-sectional areas of the inflow hole 12 and the outflow hole 13.

流路孔２１は、第１電極体Ｅ１の円形電極孔ｈと第２電極体Ｅ２の円形電極孔ｈとを連絡する電極間流路孔２１ａと、第１電極体Ｅ１の円形電極孔ｈの上流側でこれと連絡する上流側流路孔２１ｂと、第２電極体Ｅ２の円形電極孔ｈの下流側でこれと連絡する下流側流路孔２１ｃとから成る。   The flow path hole 21 includes an inter-electrode flow path hole 21a that connects the circular electrode hole h of the first electrode body E1 and the circular electrode hole h of the second electrode body E2, and the circular electrode hole h of the first electrode body E1. It consists of an upstream channel hole 21b communicating with this on the upstream side, and a downstream channel hole 21c communicating with this on the downstream side of the circular electrode hole h of the second electrode body E2.

かような測定器の機械的構成においては、被測定流体は流入孔１２から上流側流路孔２１ｂ，第１電極体Ｅ１の円形電極孔ｈ，電極間流路孔２１ａ，第２電極体Ｅ２の円形電極孔ｈ，下流側流路孔２１ｃを介して流出孔１３へ流下して行き、第１電極体Ｅ１の円形電極孔ｈの孔縁と第２電極体Ｅ２の円形電極孔ｈの孔縁とが電極間流路孔２１ａを隔てた電極対となっており、この電極間流路孔２１ａ内に電界が集中する。そして、被測定流体は円形電極孔ｈ内と流路孔２１内を流れるだけであるので、流動抵抗の増大を招かずに済む。また流体内に含まれる気泡などが円形電極孔ｈや流路孔２１の内面に留められずに流下するため、誤検出を防げる。   In such a mechanical configuration of the measuring instrument, the fluid to be measured flows from the inflow hole 12 to the upstream flow path hole 21b, the circular electrode hole h of the first electrode body E1, the interelectrode flow path hole 21a, and the second electrode body E2. The circular electrode hole h of the first electrode body E1 flows down to the outflow hole 13 through the downstream flow path hole 21c, the hole edge of the circular electrode hole h of the first electrode body E1 and the hole of the circular electrode hole h of the second electrode body E2 The edge forms an electrode pair separating the interelectrode channel hole 21a, and the electric field concentrates in the interelectrode channel hole 21a. Since the fluid to be measured only flows through the circular electrode hole h and the flow path hole 21, it is not necessary to increase the flow resistance. Further, since bubbles contained in the fluid flow down without being retained on the inner surfaces of the circular electrode hole h and the flow path hole 21, erroneous detection can be prevented.

本例の電極ホルダ２０は、第１電極体Ｅ１及び第２電極体Ｅ２をインサートとする樹脂成形品ではなく、流路孔２１に直交して第１電極体Ｅ１を差し込み保持可能な第１電極収納穴２２と、流路孔２１に直交して第２電極体Ｅ２を差し込み保持可能な第２電極収納穴２３とを備えているため、電極体Ｅ１，Ｅ２の交換や清掃が可能となっている。   The electrode holder 20 of this example is not a resin molded product using the first electrode body E1 and the second electrode body E2 as inserts, but a first electrode that can be inserted and held perpendicular to the flow path hole 21. Since the storage hole 22 and the second electrode storage hole 23 that can be inserted and held perpendicular to the flow path hole 21 are provided, the electrode bodies E1 and E2 can be replaced and cleaned. Yes.

測定ケース１０は、流入管を接続する流入側接手部１２ａと流出管を接続する流出側接手部１３ａを有しているため、簡単な管接続作業だけで、燃料電池発電システムにおける純水の汚れと気泡（水枯れ）の検出を行うことができる。   Since the measurement case 10 has an inflow side joint 12a for connecting the inflow pipe and an outflow side joint 13a for connecting the outflow pipe, the pure water contamination in the fuel cell power generation system can be achieved only by simple pipe connection work. And detection of bubbles (withered by water).

また、流路孔２１の断面積は流入孔１２及び流出孔１３の断面積に比して狭くなっているため、流入孔１２及び流出孔１３内の流体の流速が低速であっても、流路孔２１内の流速を高めることがきるので、気泡や異物が円形電極孔ｈや流路孔２１の内面に付着し難くなり、誤検出を防げる。更に、円形電極孔ｈが円柱部Ｕの直径方向に形成されているため、円柱部Ｕを軸回転させて円形電極孔ｈの向きを変えることで、円形電極孔ｈと流路孔２１との整合を図ることができる。   Further, since the cross-sectional area of the flow path hole 21 is narrower than the cross-sectional areas of the inflow hole 12 and the outflow hole 13, the flow rate of the fluid in the inflow hole 12 and the outflow hole 13 is low. Since the flow velocity in the passage hole 21 can be increased, it is difficult for bubbles and foreign matters to adhere to the inner surfaces of the circular electrode hole h and the flow path hole 21, thereby preventing erroneous detection. Furthermore, since the circular electrode hole h is formed in the diameter direction of the cylindrical part U, the circular part of the circular electrode hole h and the flow path hole 21 are changed by rotating the cylindrical part U to change the direction of the circular electrode hole h. Alignment can be achieved.

電極体Ｅ１，Ｅ２にはＯリングＱが装着されているため、流体の電極収納穴２２，２３内での漏洩を防止できる。更に、電極体Ｅ１，Ｅ２を電極収納穴２２，２３に差し込んだ際、円形電極孔ｈと流路孔２１との合致が視認できないときでも、各電極体Ｅ１，Ｅ２には回し位置決め用見当部（マーカー）Ｗが形成されているため、回し位置決め用見当部Ｗの位置合わせで合致を図ることができる。そして、電極体Ｅ１，Ｅ２は鍔部Ｆと回し位置決め用見当部Ｗと間に肉盗みの縮径部Ｓを一体的に有しているため、肉盗みの縮径部Ｓのない場合に比して肉盗みの縮径部Ｓ同士により対向面積と対向距離が減少する分、寄生容量を抑制でき、誘電率測定の分解能を高めることができる。   Since the O-rings Q are attached to the electrode bodies E1 and E2, it is possible to prevent leakage of fluid in the electrode housing holes 22 and 23. Further, when the electrode bodies E1 and E2 are inserted into the electrode housing holes 22 and 23, even if the match between the circular electrode hole h and the flow path hole 21 cannot be visually recognized, the electrode bodies E1 and E2 are turned to the positioning register portions. Since the (marker) W is formed, it is possible to achieve matching by aligning the registration portion W for turning positioning. And since the electrode bodies E1 and E2 integrally have the reduced diameter portion S for meat stealing between the flange portion F and the rotating registration portion W, compared with the case where there is no reduced diameter portion S for meat theft. Thus, the parasitic capacitance can be suppressed and the resolution of the dielectric constant measurement can be increased as much as the opposing area and the opposing distance are reduced by the reduced diameter portions S of the stealing meat.

図５は上記の流体の導電率兼誘電率測定器を用いた検出回路を示す回路ブロック図である。この検出回路は、第１電極体Ｅ１を送信電極とし、第２電極体Ｅ２を受信電極とし、連動スイッチ群と送信側回路と受信側回路とから成る。   FIG. 5 is a circuit block diagram showing a detection circuit using the above-described fluid conductivity / dielectric constant measuring device. This detection circuit includes a first electrode body E1 as a transmission electrode, a second electrode body E2 as a reception electrode, and includes an interlocking switch group, a transmission side circuit, and a reception side circuit.

先ず、送信側回路は、１ｍｓの切換周期（パルス幅）の±５Ｖ矩形波で極性反転を繰り返す５００Ｈｚの導電率用周波数信号Ｓ_１を発信する導電率用発信回路４０Ａと、０．００５ｍｓの切換周期（パルス幅）の±５Ｖ矩形波で極性反転を繰り返す１００ＫＨｚの誘電率用周波数信号Ｓ_２を発信する誘電率用発信回路４０Ｂと、５ｍｓの切換周期（パルス幅）の±５Ｖ矩形波で極性反転を繰り返す１００Ｈｚのスイッチ切換用周波数信号Ｓ_３を発信するスイッチ切換用発信回路４０Ｃを備えている。導電率用発信回路４０Ａの出力端子は第１アナログスイッチＳＷ_１を介して送信電極としての第１電極体Ｅ１の端子ピンＰに接続されており、また誘電率用発信回路４０Ｂの出力端子は第２アナログスイッチＳＷ_２を介して第１電極体Ｅ１の端子ピン部Ｐに接続されている。 First, the transmitter circuit, 1 ms of the switching period and conductivity for outgoing circuit 40A that transmits the conductivity for frequency signals _{S 1} of 500Hz repeating polarity reversal in ± 5V square wave (pulse width), switching of 0.005ms periodic polarity ± 5V square wave (pulse width) of ± 5V and outgoing circuit 40B for the dielectric constant for transmitting a dielectric constant for the frequency signal S ₂ of 100KHz repeating polarity reversal in the rectangular wave, 5 ms of the switching period (pulse width) and a switch switching oscillation circuit 40C that transmits 100Hz switch switching frequency signal S ₃ to repeat the inversion. Output terminals of the conductivity for the outgoing circuit 40A output terminal of the first through the analog switch SW ₁ is connected to the terminal pin P of the first electrode (E1) as a transmitting electrode, and the dielectric constant for the outgoing circuit 40B is first 2 are connected to the terminal pin portion P of the first electrode (E1) via the analog switch SW _2.

他方、受信側回路は、導電率測定回路５０と誘電率測定回路６０とから成り、導電率測定回路５０は、入力端子が第３アナログスイッチＳＷ_３を介して受信電極としての第２電極体Ｅ２の端子ピンＰに接続された導電率用受信回路５０Ａと、ピークホールド回路５１Ａと、コンパレータ５２Ａとから成り、誘電率測定回路６０は、入力端子が第４アナログスイッチＳＷ_４を介して第２電極体Ｅ２の端子ピン部Ｐに接続された誘電率用受信回路６０Ｂと、充放電回路６１Ｂと、コンパレータ６２Ｂとから成る。 On the other hand, the receiving side circuit comprises a conductivity measuring circuit 50 and the dielectric constant measuring circuit 60., conductivity measurement circuit 50, the second electrode member as the receiving electrode input terminal through a third analog switch SW ₃ E2 and conductivity receiver circuit 50A connected to the terminal pin P of the peak hold circuit 51A, composed of a comparator 52A, a dielectric constant measuring circuit 60, a second electrode input terminal through a fourth analog switch SW ₄ It comprises a dielectric constant receiving circuit 60B connected to the terminal pin portion P of the body E2, a charge / discharge circuit 61B, and a comparator 62B.

そして、スイッチ切換用発信回路４０Ｃからのスイッチ切換用周波数信号Ｓ_３は４つのアナログスイッチＳＷ_１〜ＳＷ_４の制御端子に供給されており、アナログスイッチＳＷ_１〜ＳＷ_４を５ｍｓの切換周期でオン／オフ制御する。導電率用の第１アナログスイッチＳＷ_１及第３アナログスイッチＳＷ_３と誘電率用の第２アナログスイッチＳＷ_２及び第４アナログスイッチＳＷ_４のオン／オフ制御は５ｍｓの切換周期毎で排他的に行われる。即ち、第１アナログスイッチＳＷ_１及第３アナログスイッチＳＷ_３のオン制御は第２アナログスイッチＳＷ_２及び第４アナログスイッチＳＷ_４のオフ制御であり、逆に、第１アナログスイッチＳＷ_１及第３アナログスイッチＳＷ_３のオフ制御は第２アナログスイッチＳＷ_２及び第４アナログスイッチＳＷ_４のオン制御である。なお、本例においては回路構成の簡略化の観点から、電源付勢により導電率用発信回路４０Ａと誘電率用発信回路４０Ｂとスイッチ切換用発信回路４０Ｃの夫々が相互独立に発信するようになっており、そのため、導電率用周波数信号Ｓ_１と誘電率用周波数信号Ｓ_２とスイッチ切換用周波数信号Ｓ_３の三者間では非同期となっているが、高周波発信回路としての誘電率用発信回路４０Ｂの誘電率用周波数信号Ｓ_２を分周して導電率用周波数信号Ｓ_１とスイッチ切換用周波数信号Ｓ_３とを生成し、三者間で同期をとっても構わない。 The ON switch switching frequency signal _{S 3} from the switch switching transmission circuit 40C is supplied to the four control terminals of the analog switches _SW 1 to SW _4, the analog switch _SW 1 to SW ₄ in the switching period of 5ms Control off / on. The on / off control of the first analog switch SW _{1 and the} third analog switch SW ₃ for conductivity, the second analog switch SW ₂ for dielectric constant, and the fourth analog switch SW ₄ is exclusively performed at every 5 ms switching period. Done. That is, the on control of the first analog switch SW _{1 and the} third analog switch SW _{3 is} the off control of the second analog switch SW ₂ and the fourth analog switch SW ₄ , and conversely, the first analog switch SW _{1 and the} third analog switch SW 4. The off control of the analog switch SW ₃ is the on control of the second analog switch SW ₂ and the fourth analog switch SW ₄ . In this example, from the viewpoint of simplifying the circuit configuration, each of the conductivity transmission circuit 40A, the dielectric constant transmission circuit 40B, and the switch switching transmission circuit 40C is transmitted independently from each other by energizing the power source. For this reason, the frequency signal S ₁ for conductivity, the frequency signal S ₂ for dielectric constant, and the frequency signal S ₃ for switch switching are asynchronous, but the transmission circuit for dielectric constant as a high frequency transmission circuit. 40B dielectric constant for frequency signal S ₂ by dividing generates a frequency signals S ₁ and switch switching frequency signal S ₃ for the conductivity of the take may synchronization tripartite.

導電率用受信回路５０Ａは、第２電極体Ｅ２から第３アナログスイッチＳＷ_３を介して受ける信号電流を電導率用入力電圧に変換するための受端抵抗（図示せず）と、その電導率用入力電圧から５００Ｈｚの信号電圧を取り出すためのバンドパスフィルタ（図示せず）と、ノイズ除去フィルタ（図示せず）とを有している。また同様に、誘電率用受信回路６０Ｂは、第２電極体Ｅ２から第４アナログスイッチＳＷ_４を介して受ける信号電流を誘電率用入力電圧に変換するための受端抵抗（図示せず）と、その誘電率用入力電圧から１００ＫＨｚの信号電圧を取り出すためのバンドパスフィルタ（図示せず）と、ノイズ除去フィルタ（図示せず）とを有している。 Conductivity receiver circuit 50A includes a receiving end resistor for converting the signal current received from the second electrode member E2 through the third analog switch SW ₃ in the conductivity for the input voltage (not shown), the conductivity A band-pass filter (not shown) for extracting a signal voltage of 500 Hz from the input voltage, and a noise removal filter (not shown). Similarly, the dielectric constant for the receiving circuit 60B includes a receiving end resistor for converting the signal current received from the second electrode member E2 through the fourth analog switch SW ₄ on the dielectric constant input voltage (not shown) And a band-pass filter (not shown) for extracting a signal voltage of 100 KHz from the dielectric constant input voltage, and a noise removal filter (not shown).

ピークホールド回路５１Ａは、耐ノイズ性の点からリセット回路を具備しておらず、また５ｍｓ毎に間欠する５ｍｓのスイッチオフ期間を無視できるようにするため、比較的長い放電時定数４７０ｍｓの充電回路を備えており、スイッチオン期間の終期電圧を自己保持できるようになっている。コンパレータ５２Ａは、５ｍｓのスイッチオフ期間によるリップ電圧の影響を抑えるためにヒステリシス機能を備えている。   The peak hold circuit 51A is not provided with a reset circuit in terms of noise resistance, and a charging circuit having a relatively long discharge time constant of 470 ms so that the 5 ms switch-off period intermittent every 5 ms can be ignored. The terminal voltage during the switch-on period can be self-maintained. The comparator 52A has a hysteresis function in order to suppress the influence of the lip voltage due to the 5 ms switch-off period.

充放電回路６１Ｂは、図６（Ａ）に示す如く、誘電率用受信回路６０Ｂからの信号電圧を増幅する増幅器ＡＭＰと、電源電圧Ｖ_ＣＣに電流制限抵抗Ｒを介してプルアップされて成る充放電用コンデンサＣと、増幅器ＡＭＰのアンプ出力Ｖ_ＡＭＰを第１の閾値電圧Ｖ_１と比較し、アンプ出力Ｖ_ＡＭＰが第１の閾値電圧Ｖ_１を超えるときは比較出力Ｖ_ＣＭＰを接地電位に短絡して充放電用コンデンサＣの電荷を瞬間放電する放電スイッチ用コンパレータＣＭＰとを有している。そして、コンパレータ６２Ｂは比較出力Ｖ_ＣＭＰを第２の閾値電圧Ｖ_２と比較し、比較出力Ｖ_ＣＭＰが第２の閾値電圧Ｖ_２を超えるときは異常信号としてハイレベル信の水枯れ検出信号Ｖ_Ｏを出力する。 As shown in FIG. 6A, the charging / discharging circuit 61B includes an amplifier AMP that amplifies the signal voltage from the dielectric constant receiving circuit 60B, and a charging / pulling circuit that is pulled up to the power supply voltage _VCC via a current limiting resistor R. The discharge capacitor C and the amplifier output V _AMP of the amplifier _AMP are compared with the _first threshold voltage V _{1. When} the amplifier output V _AMP exceeds the first threshold voltage V ₁ , the comparison output V _CMP is short-circuited to the ground potential. And a discharge switch comparator CMP for instantaneously discharging the charge of the charge / discharge capacitor C. Then, the comparator 62B compares the comparison output V _CMP with the second threshold voltage V _2, and when the comparison output V _CMP exceeds the second threshold voltage V ₂ , the high level signal withering detection signal V _{O is} detected as an abnormal signal. Is output.

次に、上記検出回路の動作を説明する。第１アナログスイッチＳＷ_１と第２アナログスイッチＳＷ_２とは、１００Ｈｚのスイッチ切換用周波数信号Ｓ_３によって、５ｍｓのスイッチオン切換周期で排他的にオン／オフ動作を繰り返すため、第１電極体Ｅ１の円形電極孔ｈの孔縁から被測定流体に放射する送信信号は、５ｍｓのスイッチ切換周期に亘って発信する１ｍｓのパルス幅で連続約５パルスの導電率用周波数信号Ｓ_１と、５ｍｓのスイッチ切換周期に亘って発信する０．００５ｍｓのパルス幅で連続約１０００パルスの誘電率用周波数信号Ｓ_２とが交互に切り換わるものとなっている。受信側の第３アナログスイッチＳＷ_３は第１アナログスイッチＳＷ_１と同期してオン／オフ動作を繰り返すため、そのスイッチオン期間の５ｍｓにおいては第３アナログスイッチＳＷ_３から導電率用受信回路５０Ａを介してピークホールド回路５１Ａの入力にはパルス幅約１ｍｓの連続約５パルスが到来し、そのスイッチオフ期間においてはパルスゼロとなる。他方、第４アナログスイッチＳＷ_４は第２アナログスイッチＳＷ_２と同期してオン／オフ動作を繰り返すため、そのスイッチオン期間の５ｍｓにおいては第４アナログスイッチＳＷ_４から誘電率用受信回路６０Ｂを介して充放電回路６１Ｂの入力にはパルス幅約０．００５ｍｓの連続約１０００パルスが到来し、そのオフ期間においてはゼロとなる。 Next, the operation of the detection circuit will be described. Since the first analog switch SW ₁ and the second analog switch SW ₂ repeat the on / off operation exclusively at a switch-on switching period of 5 ms by the switch switching frequency signal S _{3 of} 100 Hz, the first electrode body E1 The transmission signal radiated from the edge of the circular electrode hole h to the fluid to be measured is a conductivity frequency signal S _{1 of} about 5 pulses continuously with a pulse width of 1 ms transmitted over a switch switching period of 5 ms, and 5 ms. and the frequency signal S ₂ for the dielectric constant of the continuous about 1000 pulses with a pulse width of 0.005ms originating over switch switching period has become that alternately switched. Since the third analog switch SW ₃ on the receiving side repeats the on / off operation in synchronization with the first analog switch SW ₁ , the conductivity receiving circuit 50A is switched from the third analog switch SW ₃ during the switch on period of 5 ms. Thus, about 5 continuous pulses with a pulse width of about 1 ms arrive at the input of the peak hold circuit 51A, and the pulse becomes zero during the switch-off period. On the other hand, the fourth analog switch SW ₄ via the second analog switch SW ₂ in synchronization with to repeat the ON / OFF operation, the receiving circuit 60B for the dielectric constant from the fourth analog switch SW ₄ in 5ms of the switch-on time Thus, about 1000 continuous pulses having a pulse width of about 0.005 ms arrive at the input of the charge / discharge circuit 61B, and become zero during the off period.

５００Ｈｚの導電率用周波数信号Ｓ_１は低周波数信号であるため、抵抗性の方が容量性よりも遥かに大きく、ピークホールド回路５１Ａの入力パルス波高値（電圧値）の如何は被測定流体（例えば純水）の汚れ（導電率，電気伝導度）に専ら依存し、汚れが増すにつれ導電率が高まり、入力パルス波高値が次第に高くなる。即ち、ピークホールド回路５１Ａのアナログ出力は汚れに依存する導電率を反映している。ピークホールド回路５１Ａはスイッチオフ期間でも直前のスイッチオン期間の終期電圧を保持できるように充電回路を具備しているため、被測定流体の汚れが進むと、徐々にピーク値が上昇し、所定の閾値電圧を超えると、コンパレータ５２Ａの出力電圧がローレベルからハイレベルへ反転し、これにより「汚れ異常」が報知される。 Since the frequency signal S ₁ for conductivity of 500 Hz is a low frequency signal, the resistance is much larger than the capacitance, and the input pulse peak value (voltage value) of the peak hold circuit 51A depends on the fluid to be measured ( For example, it depends solely on dirt (conductivity, electrical conductivity) of pure water), and as the dirt increases, the conductivity increases and the input pulse peak value gradually increases. That is, the analog output of the peak hold circuit 51A reflects the conductivity depending on the dirt. Since the peak hold circuit 51A is equipped with a charging circuit so that the final voltage of the immediately preceding switch-on period can be maintained even during the switch-off period, the peak value gradually increases as the fluid to be measured increases, When the threshold voltage is exceeded, the output voltage of the comparator 52A is inverted from the low level to the high level, thereby informing the “dirt abnormality”.

他方、１００ＫＨｚの誘電率用周波数信号Ｓ_２は高周波数信号であるため、容量性の方が抵抗性よりも遥かに大きく、充放電回路６１Ｂの入力パルス波高値（電圧値）の如何は被測定流体（例えば純水）の誘電率に専ら依存し、第１電極体Ｅ１の円形電極孔ｈと第２電極体Ｅ１の円形電極孔ｈとに挟まれた電極間流路孔に気泡が入来するときは、誘電率が急激に減少するため静電容量が急減し、入力パルス波高値が激減する。図６（Ｂ）に示す如く、第４アナログスイッチＳＷ_４のスイッチオン期間においては、増幅器ＡＭＰのアンプ出力Ｖ_ＡＭＰには１００ＫＨｚの誘電率用周波数信号Ｓ_２に基づきパルス幅約０．００５ｍｓの正負都合連続約１０００パルスが現れるが、信号電圧がその各正パルスの立ち上がり毎（約０．０１ｍｓ毎）で第１の閾値電圧Ｖ_１を超えると、放電スイッチ用コンパレータＣＭＰの比較出力Ｖ_ＣＭＰが接地し、充放電用コンデンサＣを瞬間放電せしめる。逆に、信号電圧が各正パルスの立ち下がり毎（約０．０１ｍｓ毎）で第１の閾値電圧Ｖ_１から落ちると、放電スイッチ用コンパレータＣＭＰの比較出力Ｖ_ＣＭＰが非接地状態となり、充放電用コンデンサＣが電源電圧Ｖ_ＣＣから電流制限抵抗Ｒを介して緩慢充電される。この緩慢充電の時定数は本例では第４アナログスイッチＳＷ_４のスイッチオン期間の５ｍｓよりも大きな３０ｍｓとしてある。つまり、第４アナログスイッチＳＷ_４のスイッチオン期間においては信号電圧の増減に基づき瞬間放電と緩慢充電の充放電が約５００回繰り繰り返されるが、放電時定数（殆どゼロ）が充電時定数（３０ｍｓ）よりも極めて小さいため、比較出力Ｖ_ＣＭＰ、即ち充電電圧は殆ど常にゼロ近傍にある。 On the other hand, since the dielectric constant for the frequency signal S ₂ of 100KHz which is a high-frequency signal, much larger than is more capacitive resistance, whether the input pulse peak value of the charging and discharging circuit 61B (voltage value) to be measured Depending on the dielectric constant of the fluid (for example, pure water), bubbles come into the inter-electrode channel hole sandwiched between the circular electrode hole h of the first electrode body E1 and the circular electrode hole h of the second electrode body E1. When this occurs, the dielectric constant decreases rapidly, so the capacitance decreases rapidly, and the input pulse peak value decreases drastically. As shown in FIG. 6 (B), in the fourth switch-on period of the analog switch SW _4, positive and negative pulse width of about 0.005ms based on the frequency signal _{S 2} for the dielectric constant of 100KHz to the amplifier output _{V AMP} amplifier AMP Although convenient continuous about 1000 pulse appears, when the signal voltage exceeds the first threshold voltages _{V 1} at the rising per the respective positive pulse (approximately every 0.01ms), the comparison output _{V CMP} of the comparator CMP discharge switch ground Then, the charging / discharging capacitor C is instantaneously discharged. Conversely, when the signal voltage falls from the first threshold voltages V ₁ at every falling edge of the positive pulse (approximately every 0.01ms), the comparison output V _CMP of the comparator CMP discharge switch is rendered non-grounded state, the charge and discharge use the capacitor C is slowly charged through the current limiting resistor R from the power supply voltage V _CC. The time constant of this slow charging in this example is a major 30ms than 5ms switch-on period of the fourth analog switch SW _4. That is, during the switch-on period of the fourth analog switch SW ₄ , instantaneous discharge and slow charge / discharge are repeated about 500 times based on the increase or decrease of the signal voltage, but the discharge time constant (almost zero) is the charge time constant (30 ms). ), The comparison output V _{CMP, that} is, the charging voltage is almost always near zero.

一方、スイッチＳＷ_４のスイッチオフ期間においては増幅器ＡＭＰのアンプ出力Ｖ_ＡＭＰがゼロとなっているため、放電スイッチ用コンパレータＣＭＰの比較出力Ｖ_ＣＭＰが常に非接地状態であり、電源電圧Ｖ_ＣＣから充放電用コンデンサＣに対し５ｍｓに亘り電流制限抵抗Ｒを介して充電されるので、スイッチＳＷ_４のスイッチオフ期間の終期では充電電圧（比較出力Ｖ_ＣＭＰ）が所定の電圧Ｖ_３に達する。そして、次のスイッチＳＷ_４のスイッチオン期間において受信信号が到来していると、前述のように、充放電を繰り返し、充電電圧（比較出力Ｖ_ＣＭＰ）がゼロ近傍となるが、図５（Ｂ）に示す如く、このスイッチＳＷ_４のスイッチオン期間のうち例えば時刻ｔ_１において第１電極体Ｅ１の円形電極孔ｈと第２電極体Ｅ１の円形電極孔ｈとの間の被測定流体中に気泡が入来すると、空気の誘電率は水のそれの約１／８０であるので、電極間の誘電率が急激に低下し、誘電率用周波数信号Ｓ_２が発信しているにも拘わらずアンプ出力Ｖ_ＡＭＰの方が殆どゼロとなり、コンパレータＣＭＰの比較出力Ｖ_ＣＭＰが非接地となるので、充放電用コンデンサＣへの充電が早めに開始され、次のスイッチオフ期間の終期では比較出力Ｖ_ＣＭＰが所定の電圧Ｖ_３を超えて設定した第２の閾値電圧Ｖ_２を超えるときは、コンパレータ６２Ｂの水枯れ検出信号Ｖ_Ｏがローレベルからハイレベルへ反転し、「水枯れ検出」を報知する。 On the other hand, since the amplifier output V AMP of the amplifier _AMP is zero during the switch-off period of the switch SW ₄ , the comparison output V _CMP of the discharge switch comparator _CMP is always in the non-ground state and _charged from the power supply voltage VCC. Since the discharging capacitor C is charged through the current limiting resistor R for 5 ms, the charging voltage (comparison output V _CMP ) reaches a predetermined voltage V ₃ at the end of the switch-off period of the switch SW ₄ . When the received signal has arrived at the switch-on period of the next switch SW _4, as described above, repeated charge and discharge, although the charge voltage (comparison output V _CMP) is near zero, FIG. 5 (B as shown in), to be measured in the fluid between the circular electrode hole h of the circular electrode apertures h and the second electrode (E1) of the first electrode (E1), for example, in the time t ₁ of the switch-on period of the switch SW ₄ When bubbles are incoming, since the dielectric constant of air is about 1/80 of that of water, reduced dielectric constant sharply between the electrodes, despite the dielectric constant for the frequency signal S ₂ is transmitting Since the amplifier output V _AMP is almost zero and the comparison output V CMP of the comparator _CMP is not grounded, charging to the charging / discharging capacitor C is started earlier, and at the end of the next switch-off period, the comparison output V _CMP is started. given _CMP is When more than the second threshold voltage V ₂ is set to exceed the voltage V _3, the water withered detection signal V _O of the comparator 62B is inverted from the low level to the high level, it informs the "water withering detection".

アンプ出力Ｖ_ＡＭＰがゼロ近傍となるときに充放電用コンデンサＣへの充電が開始されるが、このアンプ出力Ｖ_ＡＭＰがゼロ近傍となる場合は、スイッチＳＷ_４のスイッチオフ期間の開始時点か、或いはスイッチＳＷ_４のスイッチオン期間において気泡が存在する時点のいずれかである。なお、スイッチＳＷ_４のスイッチオフ期間から気泡が存在し続けるときは次のスイッチオン期間の開始時点からアンプ出力Ｖ_ＡＭＰがゼロ近傍となる。水枯れが発生する場合にはスイッチＳＷ_４のスイッチオン期間においても充放電用コンデンサＣの充電時間が余分に追加されて第４アナログスイッチＳＷ_４のスイッチオフ期間（５ｍｓ）よりも長なり、これにより充電電圧が５ｍｓに亘る充電電圧である所定電圧Ｖ_３よりも高くなる。この誘電率測定用回路では、信号電圧を充電するピークホールド回路を用いることなく、電源電圧Ｖ_ｃｃにプルアップされて成る充放電コンデンサに対して信号電圧の増減に基づいて放電制御するようにしており、事実上、充放電コンデンサに対する充電時間の長短比較により水枯れを高精度に検出できる。 While charging of the charging and discharging capacitor C is started when the amplifier output V _AMP is near zero, if the amplifier output V _AMP is near zero, or the beginning of the switch-off period of the switch SW _4, or at any point where bubbles exist in the switch-on period of the switch SW _4. When bubbles continue to exist from the switch-off period of the switch SW _4, the amplifier output V _AMP becomes _close to zero from the start of the next switch-on period. If water wither occurs becomes long than the fourth switch-off period of the analog switch SW ₄ is extra added charging time of the charge and discharge capacitor C (5 ms) in the switch-on period of the switch SW _4, which As a result, the charging voltage becomes higher than the predetermined voltage V ₃ which is a charging voltage over 5 ms. In this dielectric constant measurement circuit, discharge control is performed on the charge / discharge capacitor pulled up to the power supply voltage _Vcc based on the increase / decrease of the signal voltage without using a peak hold circuit for charging the signal voltage. In fact, it is possible to detect withering water with high accuracy by comparing the charging time of the charging / discharging capacitor.

１０…測定ケース
１１…ホルダ収納穴
１２…流入孔
１２ａ…流入側接手部
１３…流出孔
１３ａ…流出側接手部
２０…電極ホルダ
２１…流路孔
２１ａ…電極間流路孔
２１ｂ…上流側流路孔
２１ｃ…下流側流路孔
２２…第１電極収納穴
２３…第２電極収納穴
３０…ホルダカバー
３１…カバー孔
４０Ａ…導電率用発信回路
４０Ｂ…誘電率用発信回路
４０Ｃ…スイッチ切換用発信回路
４５…回路基板
４６…スルーホール
５０…導電率測定回路
５０Ａ…導電率用受信回路
５１Ａ…ピークホールド回路
５２Ａ，６２Ｂ…コンパレータ
６０…誘電率測定回路
６０Ｂ…誘電率用受信回路
６１Ｂ…充放電回路
ＡＭＰ…増幅器
Ｃ…充放電用コンデンサ
ＣＭＰ…放電スイッチ用コンパレータ
Ｅ１…第１電極体
Ｅ２…第２電極体
Ｆ…鍔部
ＧＮＤ…接地
ｈ…円形電極孔
Ｍ…カバー孔差し込み部
Ｐ…端子ピン部
Ｑ…Ｏリング
Ｒ…電流制限抵抗
Ｓ…肉盗みの縮径部
Ｓ_１…導電率用周波数信号
Ｓ_２…誘電率用周波数信号
Ｓ_３…スイッチ切換用周波数信号
ＳＷ_１…第１アナログスイッチ
ＳＷ_２…第２アナログスイッチ
ＳＷ_３…第３アナログスイッチ
ＳＷ_４…第４アナログスイッチ
ｔ_１…気泡入来時刻
Ｕ…有孔円柱部
Ｖ…Ｏリング装着用縮径部
Ｖ_ＡＭＰ…アンプ出力
Ｖ_１…第１の閾値電圧
Ｖ_２…第２の閾値電圧
Ｖ_３…所定電圧
Ｖ_ＣＭＰ…比較出力
Ｖ_ｃｃ…電源電圧
Ｖ_Ｏ…水枯れ検出信号
Ｗ…回し位置決め用見当部（マーカー） DESCRIPTION OF SYMBOLS 10 ... Measurement case 11 ... Holder accommodation hole 12 ... Inflow hole 12a ... Inflow side joint part 13 ... Outflow hole 13a ... Outflow side joint part 20 ... Electrode holder 21 ... Channel hole 21a ... Inter-electrode channel hole 21b ... Upstream side flow Path hole 21c ... Downstream channel hole 22 ... First electrode accommodation hole 23 ... Second electrode accommodation hole 30 ... Holder cover 31 ... Cover hole 40A ... Conductivity transmission circuit 40B ... Dielectric constant transmission circuit 40C ... Switch switching Transmission circuit 45 ... Circuit board 46 ... Through hole 50 ... Conductivity measurement circuit 50A ... Conductivity reception circuit 51A ... Peak hold circuit 52A, 62B ... Comparator 60 ... Dielectric constant measurement circuit 60B ... Dielectric constant reception circuit 61B ... Charge / discharge Circuit AMP ... Amplifier C ... Capacitor for charge / discharge CMP ... Comparator for discharge switch E1 ... First electrode body E2 ... Second electrode body F ... Gutter GND ... Ground h ... Circular electrode hole M Cover hole insertion portion P ... terminal pin section Q ... O-ring R ... current limiting resistor S ... thinned tapered segment S 1 _... frequency signal Conductivity S 2 _... permittivity for frequency signals S 3 _... switch switching frequency signal SW ₁ ... 1st analog switch SW ₂ ... 2nd analog switch SW ₃ ... 3rd analog switch SW ₄ ... 4th analog switch t ₁ ... Bubble arrival time U ... Perforated cylindrical part V ... Reduced diameter part for mounting O-ring V _AMP ... Amplifier output V ₁ ... First threshold voltage V ₂ ... Second threshold voltage V ₃ ... Predetermined voltage V _CMP ... Comparison output V _cc ... Power supply voltage V _O ... Water dryness detection signal W ... Turn positioning register (marker)

Claims (9)

第１電極孔を持つ第１電極体と、第２電極孔を持つ第２電極体と、第１電極体及び第２電極体を相隔てて保持する電極ホルダとを備え、この電極ホルダにおいて前記第１電極孔と前記第２電極孔とが相向い合う状態でこれらに合致する流路孔が貫通形成されて成ることを特徴とする流体の導電率兼誘電率測定器。 A first electrode body having a first electrode hole; a second electrode body having a second electrode hole; and an electrode holder for holding the first electrode body and the second electrode body apart from each other. A fluid conductivity / dielectric constant measuring instrument, wherein a flow path hole matching the first electrode hole and the second electrode hole is formed in a state where the first electrode hole and the second electrode hole face each other. 請求項１に記載の流体の導電率兼誘電率測定器において、前記電極ホルダは、前記流路孔に直交して前記第１電極体を差し込み保持可能な第１電極収納穴と、前記流路孔に直交して前記第２電極体を差し込み保持可能な第２電極収納穴を備えて成ることを特徴とする流体の導電率兼誘電率測定器。 2. The fluid conductivity / dielectric constant measuring device according to claim 1, wherein the electrode holder includes a first electrode accommodation hole capable of inserting and holding the first electrode body perpendicular to the flow path hole, and the flow path. A fluid conductivity / dielectric constant measuring device comprising a second electrode housing hole into which the second electrode body can be inserted and held perpendicular to the hole. 請求項１又は請求項２に記載の流体の導電率兼誘電率測定器において、前記各電極体の端子ピン部に接続可能な回路基板を組み込んだ測定ケースを備え、この測定ケースは、前記電極ホルダを差し込み保持可能なホルダ収納穴と、このホルダ収納穴に連通して前記流路孔の一方の開口に一端側が連絡すると共に他端側に流入側接手部を備える流入孔と、前記ホルダ収納穴に連通して前記流路孔の他方の開口に一端側が連絡すると共に他端側に流出側接手部を備える流出孔とを有することを特徴とする流体の導電率兼誘電率測定器。 The fluid conductivity / dielectric constant measuring device according to claim 1 or 2, further comprising a measurement case in which a circuit board connectable to a terminal pin portion of each electrode body is incorporated, and the measurement case includes the electrode A holder housing hole into which a holder can be inserted and held; an inflow hole which communicates with the holder housing hole and communicates with one opening of the flow path hole and has an inflow side joint on the other end side; and the holder housing A fluid conductivity / dielectric constant measuring instrument characterized by comprising an outflow hole that communicates with a hole and communicates with one end side of the other opening of the flow path hole and has an outflow side joint on the other end side. 請求項３に記載の流体の導電率兼誘電率測定器において、前記流路孔の断面積は前記流入孔及び前記流出孔の断面積に比して狭くなっていることを特徴とする流体の導電率兼誘電率測定器。 4. The fluid conductivity / dielectric constant measuring device according to claim 3, wherein a cross-sectional area of the flow path hole is smaller than a cross-sectional area of the inflow hole and the outflow hole. Conductivity and dielectric constant measuring instrument. 請求項３又は請求項４に記載の流体の導電率兼誘電率測定器において、前記各電極体は、直交方向に前記電極孔を持つ有孔円柱部と、この有孔円柱部から前記端子ピン部側に位置して前記有孔円柱部との間にＯリング装着用縮径部を画成する鍔部とを一体的に有し、前記Ｏリング縮径部にＯリングが装着されて成ることを特徴とする流体の導電率兼誘電率測定器。 5. The fluid conductivity / dielectric constant measuring device according to claim 3, wherein each of the electrode bodies includes a perforated cylindrical portion having the electrode holes in an orthogonal direction, and the terminal pin from the perforated cylindrical portion. And a flange portion that forms a reduced diameter portion for mounting an O-ring between the perforated cylindrical portion and is located on the portion side, and an O-ring is mounted on the O-ring reduced diameter portion. A fluid conductivity / dielectric constant measuring device. 請求項５のいずれ項に記載の流体の導電率兼誘電率測定器において、前記各電極体は、前記端子ピン部と前記鍔部との間に回し位置決め用見当部を一体的に有することを特徴とする流体の導電率兼誘電率測定器。 6. The fluid conductivity / dielectric constant measuring device according to claim 5, wherein each of the electrode bodies integrally includes a positioning register for rotation between the terminal pin portion and the flange portion. A fluid conductivity / dielectric constant measuring device. 請求項６に記載の流体の導電率兼誘電率測定器において、前記各電極体は、前記鍔部と前記回し位置決め用見当部と間に肉盗みの縮径部を一体的に有することを特徴とする流体の導電率兼誘電率測器。 7. The fluid conductivity / dielectric constant measuring device according to claim 6, wherein each of the electrode bodies integrally has a reduced diameter portion for stealing a meat between the collar portion and the turning positioning register portion. Fluid conductivity and dielectric constant measuring instrument. 請求項１乃至請求項７のいずれか一項に記載の流体の導電率兼誘電率測定器において、第１の周波数信号を発信する導電率用発信回路の出力端と前記第１電極体との間に介在する第１のスイッチと、前記第１の周波数信号によりも高い第２の周波数信号を発信する誘電率用発信回路の出力端と前記第１電極体との間に介在する第２のスイッチと、前記第２電極体と導電率測定回路との間に介在する第３のスイッチと、前記第２電極体と誘電率測定回路との間に介在する第４のスイッチと、前記第１の周波数信号よりも低いスイッチ切換用周波数信号で前記第１及び第３のスイッチと前記第２及び第３のスイッチとを排他的にオン／オフ制御することを特徴とする流体の導電率兼誘電率測定器。 The fluid conductivity / dielectric constant measuring device according to any one of claims 1 to 7, wherein an output terminal of a conductivity transmission circuit for transmitting a first frequency signal and the first electrode body are connected. A first switch interposed therebetween, and a second switch interposed between the first electrode body and the output terminal of the dielectric constant transmission circuit for transmitting a second frequency signal higher than the first frequency signal. A switch, a third switch interposed between the second electrode body and the conductivity measuring circuit, a fourth switch interposed between the second electrode body and the dielectric constant measuring circuit, and the first switch The first and third switches and the second and third switches are exclusively controlled to be turned on / off by a switch switching frequency signal lower than the first frequency signal. Rate measuring instrument. 請求項８に記載の流体の導電率兼誘電率測定器において、前記誘電率測定回路は、前記第４のスイッチから入来する信号電流を信号電圧に変換する電流／電圧変換手段と、定電圧に制限抵抗を介してプルアップされて成る充放電用コンデンサと、前記信号電圧を第１の閾値電圧と比較してこれを超えるときはオン状態となって前記充放電用コンデンサを瞬間放電せしめる放電制御手段と、前記第４のスイッチのオン期間での前記充放電用コンデンサの充電電圧を前記第４のスイッチのオフ期間終期での前記充放電用コンデンサの充電電圧値よりも高い第２の閾値電圧と比較してこれを超えるときは異常信号を出力する比較手段とを有することを特徴とする流体の導電率兼誘電率測定器。 9. The fluid conductivity / permittivity measuring device according to claim 8, wherein the permittivity measuring circuit includes a current / voltage converting means for converting a signal current coming from the fourth switch into a signal voltage, and a constant voltage. A charging / discharging capacitor that is pulled up through a limiting resistor, and a discharge that is turned on when the signal voltage exceeds the first threshold voltage and instantaneously discharges the charging / discharging capacitor. And a second threshold value that is higher than a charging voltage value of the charging / discharging capacitor at the end of an off period of the fourth switch. Comparing means for outputting an abnormal signal when exceeding a voltage compared to the voltage, a fluid conductivity / dielectric constant measuring instrument.

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