JPH0626813Y2 - Vortex flowmeter circuit - Google Patents
Vortex flowmeter circuitInfo
- Publication number
- JPH0626813Y2 JPH0626813Y2 JP2933889U JP2933889U JPH0626813Y2 JP H0626813 Y2 JPH0626813 Y2 JP H0626813Y2 JP 2933889 U JP2933889 U JP 2933889U JP 2933889 U JP2933889 U JP 2933889U JP H0626813 Y2 JPH0626813 Y2 JP H0626813Y2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- vortex
- flow rate
- signal
- terminals
- 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.)
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Description
【考案の詳細な説明】 技術分野 本考案は、渦信号を２線伝送する渦流量計変換器と、該
渦信号を受信する受信器とからなり、受信器側の切替に
より気体又は液体の流量計測を可能とする渦流量計回路
に関する。TECHNICAL FIELD The present invention comprises a vortex flowmeter converter for transmitting a vortex signal in two lines and a receiver for receiving the vortex signal. The flow rate of gas or liquid is switched by switching the receiver side. The present invention relates to a vortex flowmeter circuit that enables measurement.
従来技術 渦流量計は周知の如く、流管内に渦発生体を装着し、該
渦発生体から発生分離するカルマン渦を検出して単位時
間当りの渦の数から流量を求めるという極めて簡易な原
理と構造をもっており、渦信号は容易にパルス信号に変
換できデジタル流量信号が得られ、流量範囲も広いこと
から計装における流量検出端として有用であり、近年、
被計測流体の種類、適用範囲も拡大されている。また、
渦流量計の流量パルスのパルス定数は、ストローハル数
により定められるが、このストローハル数はレイノルズ
数に依存するので、ストローハル数が一定の範囲ではパ
ルス定数が定まり、気体、液体の密度の異なる流体であ
っても前記レイノルズ数範囲ではパルス定数を変更せず
に流量パルスを演算し、計測できるという利点もあり、
一つの渦流量計で液体、気体の流量を計測することが試
みられている。例えば、Ａの液体を計測後、蒸気洗浄
し、Ｂの液体と切替え再び蒸気洗浄しＡの液体計測をす
ることを繰返す等があげられる。この場合、Ａ液、Ｂ液
および蒸気流量は当然乍ら各々液別に計測される。BACKGROUND ART As is well known, a vortex flowmeter is an extremely simple principle in which a vortex generator is mounted in a flow tube, Karman vortices generated and separated from the vortex generator are detected, and the flow rate is calculated from the number of vortices per unit time. The vortex signal can be easily converted to a pulse signal to obtain a digital flow rate signal, and the flow rate range is wide, making it useful as a flow rate detection end in instrumentation.
The types of measurement fluids and the applicable range have been expanded. Also,
The pulse constant of the flow pulse of the vortex flowmeter is determined by the Strouhal number. Since this Strouhal number depends on the Reynolds number, the pulse constant is determined within a certain range of Strouhal number, and the density of gas and liquid is Even in the case of different fluids, there is also an advantage that the flow rate pulse can be calculated and measured without changing the pulse constant in the Reynolds number range,
It has been attempted to measure the flow rates of liquids and gases with a single vortex flowmeter. For example, after repeating measurement of the liquid A, steam cleaning, switching to the liquid B, steam cleaning again, and measurement of the liquid A are repeated. In this case, the flow rates of the liquid A, the liquid B, and the vapor are naturally measured for each liquid.
一方、渦流量計における渦の渦検出方法として渦変動圧
力または揚力変化を利用する方式が多用されているが、
これらの検出信号は、流体密度と流速２乗に比例した信
号レベルとなる。工業的用途において計測対象となる流
体で液体は密度が高く流速は小さいが、気体は密度が小
さく流速が大きいので液体と気体との渦信号の測定流量
範囲における周波数範囲および信号レベルも互いに異な
り、一つの渦信号で、液体と気体の流量を測定する場
合、従来は、液体用の信号変換器（以降単に変換器と呼
ぶ）と気体用の変換器とを併置し、各々の変換器の切替
えを、液体、気体の流体源からの流路切替え時点で手動
に切替えていた。On the other hand, a method that uses vortex fluctuation pressure or lift change is often used as a vortex detection method for vortices in vortex flowmeters.
These detection signals have signal levels proportional to the fluid density and the square of the flow velocity. In industrial applications, the liquid to be measured is liquid with high density and low flow velocity, but gas has low density and high flow velocity, so the frequency range and signal level in the measurement flow range of the eddy signal between liquid and gas are also different from each other, When measuring the flow rates of liquid and gas with one vortex signal, conventionally, a signal converter for liquid (hereinafter simply referred to as a converter) and a converter for gas are placed side by side, and each converter is switched. Was manually switched at the time of switching the flow path from the fluid source of liquid or gas.
従来技術の問題点 以上において述べた従来の渦流量計においては、変換器
を液体および気体に適用する特性の複数個用意する必要
があり、また、２線伝送する場合においても更に信号切
替手段を別に設けなければならず、高価であるばかりで
なく大形となる等の問題点があった。Problems of the Prior Art In the conventional vortex flowmeter described above, it is necessary to prepare a plurality of converters having characteristics applicable to liquids and gases, and further in the case of 2-wire transmission, a signal switching means is further required. It has to be provided separately, and there is a problem that it is not only expensive but also large in size.
問題点解決のための手段 本考案は、叙上の問題点に鑑みなされたもので、変換器
を共通にして２線伝送し、受信器側において液体又は気
体流量計測を切替え、該切替えにより作動するダイオー
ドブリッジの光ダイオードにより変換器の回路要素の回
路定数を切替可能とするスイッチを作動させるもので、
具体的には、渦センサから出力される近似正弦波の渦信
号を流量範囲の帯域で可変増幅する増幅回路と、渦信号
周波数のローパスフィルタ回路と、渦信号をパルス信号
に変換するパルス変換回路と、パルス信号を流量信号に
変換する変換回路と、該流量信号を２線伝送する第１、
第２端子を有する出力回路とからなる変換器および前記
第１、第２端子に接続する第３、第４端子と、該第３、
第４端子に直列接続する直流電源と負荷抵抗とからなる
受信器とで構成する渦流量計回路において、受信器側
は、直流電源と負荷抵抗との直列回路を第３、第４端子
の極性が反転するごとく切替え、変換器側は、第１、第
２端子の極性の何如にかかわらず出力回路に順方向の電
源を供給するダイオードブリッジを設け、且つ受信器側
の何れかの切替えで導通するダイオードを発光ダイオー
ドとし、該発光ダイオードの発光に応じて作動するスイ
ッチにより前記増幅回路のゲイン、およびフィルタ回路
におけるフィルタ定数を切替え、切替えにより液体と気
体流量計測に対応する特性をもつ変換器とする渦流量計
回路を提供するものである。Means for Solving Problems The present invention has been made in view of the above-mentioned problems, and two-wire transmission is performed with a common converter, and liquid or gas flow rate measurement is switched on the receiver side, and operation is performed by the switching. By operating the switch that can switch the circuit constant of the circuit element of the converter by the photodiode of the diode bridge
Specifically, an amplification circuit that variably amplifies the approximate sine wave vortex signal output from the vortex sensor in the flow rate range band, a low-pass filter circuit of the vortex signal frequency, and a pulse conversion circuit that converts the vortex signal into a pulse signal. A conversion circuit for converting the pulse signal into a flow rate signal, and a first circuit for transmitting the flow rate signal by two wires,
A converter including an output circuit having a second terminal, and third and fourth terminals connected to the first and second terminals, and the third and fourth terminals.
In a vortex flowmeter circuit composed of a DC power supply connected in series with a fourth terminal and a receiver composed of a load resistance, the receiver side has a series circuit of a DC power supply and a load resistance with polarities of the third and fourth terminals. , The converter side is provided with a diode bridge that supplies forward power to the output circuit regardless of the polarity of the first and second terminals, and the converter side is turned on by any switching. And a converter having characteristics corresponding to liquid and gas flow rate measurement by switching the gain of the amplifier circuit and the filter constant in the filter circuit by a switch that operates in response to the light emission of the light emitting diode. A vortex flowmeter circuit is provided.
実施例 第１図は、本考案の渦流量計回路のブロック図を示すも
ので、図中、１は渦センサで、図示しない流管に介装さ
れ、液体又は気体の流量を計測する渦流量計に内蔵され
渦変動圧力を電気信号として検出する圧電素子センサを
示す。２は渦センサ１の渦信号を増幅する増幅回路であ
り、高入力インピーダンスのチャージアンプであり、点
線で示した２１内の帰還抵抗Ｒ1および該帰還抵抗Ｒ1と
光感応スイッチＰ3の光入力により閉路し、帰還抵抗Ｒ1
に並列接続される抵抗Ｒ2による可変増幅機能を有して
いる。３はフィルタ回路で流量範囲外の渦信号に対して
高次の減衰特性を有するローパスフィルタおよびハイパ
スフィルタの組み合わせ、または、渦周波数を中心周波
数として渦周波数の変動に追尾するトラッキングフィル
タを示し、点線３１は該フィルタ回路３の回路要素であ
るコンデンサを図示したもので、例えば、コンデンサＣ
1と光感応スイッチＰ4の光入力により閉路しコンデンサ
Ｃ1に並列接続して減衰特性を変更するコンデンサＣ2を
具備している。４はシュミット回路でフィルタ回路３よ
り出力される所定レベル以上の近似正弦波の渦信号を流
量パルスに変換するものである。５は流量パルスを単位
流量パルス又はアナログ変換して瞬時流量等の流量情報
に変換する演算器、６は演算器５の信号を２線伝送する
出力回路であり、９は該出力回路６の電源、１１は負荷
抵抗である。７はダイオードブリッジで、ダイオードＤ
1、Ｄ2および発光ダイオードＤ3、Ｄ4からなり、正出力
端子７１は出力回路６の高電位側６１に、負出力端子７
２は低電位側６２に接続している。叙上の渦センサ１、
アンプ２、フィルタ回路３、シュミット回路４、演算回
路５、出力回路６、ダイオードブリッジ７は渦流量計
（図示せず）に装着される変換器Ａであり、電源９およ
び負荷抵抗１１は２線伝送される受信器Ｂを構成するも
のである。変換器Ａと受信器Ｂとの間においては、変換
器の第１端子Ｔ1と受信器側の第３端子Ｔ3および変換器
の第２端子Ｔ2と受信器側の第４端子Ｔ4とを各々伝送線
（点線で示す）で接続している。受信器側の８は切替ス
イッチで、第３、第４端子において、電源９と負荷抵抗
１１との直列回路の極性を切替えるもので対をなすスイ
ッチ８１と８２とからなっている。叙上の第１図に示し
たブロック図では、切替スイッチ８は、切替えにより測
定流体が液体又は気体であるかを選択するもので、図示
のスイッチ８１、８２が各々Ｓ1−１、Ｓ2−１が閉路さ
れているとき、気体流量を計測する場合であり、出力回
路６には第４端子Ｔ4、第２端子Ｔ2、ダイオードＤ1を
介して電圧が印加され、ダイオードＤ2、第１端子Ｔ1、
第３端子Ｔ3を経て負荷抵抗１１に帰路する。この場合
は、光感応スイッチＰ3、Ｐ4は共に応動せず開路された
ままであり、従って、アンプ２の帰還抵抗はＲ1だけで
あり、気体流量範囲で好適なゲイン特性が該帰還抵抗Ｒ
1により定められる。フィルタ回路３の場合においても
コンデンサ容量はＣ1が選ばれる。渦信号は流体密度
と、流速の２乗とに比例したレベルになり、気体の場合
は密度が小さく、流速が大きいので小流域ではアンプゲ
インを高くし、大流量域では３次のローパスフィルタを
用いて渦信号レベルを均一化するとともに、流量範囲外
では充分に減衰を与えてＳ／Ｎの向上を計っている。他
方、液体の場合は、密度が大きく、流速が小さいので小
流域ではアンプゲインを小さくし、大流域では２次〜３
次のローパスフィルタを用いている。次に、切替スイッ
チ８１、８２をＳ1−２、Ｓ2−２に切替えた場合は、液
体流量を計測する場合であり、出力回路６には第３端子
Ｔ3、第１端子Ｔ1、発光ダイオードＤ3を介して電圧が
印加され、発光ダイオードＤ4、第２端子Ｔ2を経て負荷
抵抗１１に帰路する。これらより発光ダイオードＤ3、
Ｄ4は発光し、これに応動して光感応スイッチＰ3、Ｐ4
は閉路し、アンプ２側では抵抗Ｒ1、Ｒ2が並列接続する
ことによりアンプゲインは減小し、フィルタ回路３では
コンデンサＣ1とＣ2とが並列接続されて液体流量に好適
な遮断周波特性が得られる。図においては、発光ダイオ
ードＤ3およびＤ4としたが、これらの発光ダイオードを
１個だけでなく複数並列としてもよく、また発光ダイオ
ードＤ3、Ｄ4の何れか一方を通常のダイオードとし、こ
れに代えてダイオードＤ1又はＤ2の何れか一方を発光ダ
イオードとして回路特性に応じてアンプ２又はフィルタ
回路３の回路要素を選択してよく、要は受信器Ｂ側の切
替スイッチ８の切替えにより液体流量又は気体流量に好
適なアンプ１特性およびフィルタ回路２の帯域特性のも
のにする光感応スイッチＰ3、Ｐ4又は図示しない他の光
感応スイッチの切替えが可能となればよい。Embodiment FIG. 1 is a block diagram of a vortex flowmeter circuit of the present invention. In the drawing, reference numeral 1 is a vortex sensor, which is inserted in a flow pipe (not shown) and measures the flow rate of liquid or gas. The piezoelectric element sensor which is built in the meter and detects the vortex fluctuating pressure as an electric signal is shown. 2 is an amplification circuit for amplifying a vortex signal of vortex sensor 1, a charge amplifier with high input impedance, the light of the feedback resistor R 1 and the feedback resistor R 1 and the photosensitive switch P 3 in 21 indicated by a dotted line Closed by input, feedback resistor R 1
It has a variable amplification function by a resistor R 2 connected in parallel with. Reference numeral 3 denotes a filter circuit, which is a combination of a low-pass filter and a high-pass filter having high-order damping characteristics for vortex signals outside the flow rate range, or a tracking filter which tracks vortex frequency fluctuations with the vortex frequency as the central frequency Reference numeral 31 denotes a capacitor which is a circuit element of the filter circuit 3, and for example, a capacitor C
1 and a capacitor C 2 which is closed by the light input of the photosensitive switch P 4 and is connected in parallel with the capacitor C 1 to change the attenuation characteristic. Reference numeral 4 is a Schmitt circuit which converts an approximate sine wave eddy signal of a predetermined level or higher output from the filter circuit 3 into a flow rate pulse. 5 is an arithmetic unit for converting the flow rate pulse into a unit flow rate pulse or analog conversion to flow rate information such as instantaneous flow rate, 6 is an output circuit for transmitting the signal of the arithmetic unit 5 by two lines, and 9 is a power source of the output circuit 6. , 11 are load resistances. 7 is a diode bridge, which is a diode D
1 , D 2 and light emitting diodes D 3 and D 4 , and the positive output terminal 71 is connected to the high potential side 61 of the output circuit 6 and the negative output terminal 7
2 is connected to the low potential side 62. Vortex sensor 1,
The amplifier 2, the filter circuit 3, the Schmitt circuit 4, the arithmetic circuit 5, the output circuit 6, and the diode bridge 7 are the converter A mounted on the vortex flowmeter (not shown), and the power source 9 and the load resistor 11 are two wires. It constitutes the receiver B to be transmitted. Between the converter A and the receiver B, a first terminal T 1 of the converter, a third terminal T 3 of the receiver side, a second terminal T 2 of the converter and a fourth terminal T 4 of the receiver side are provided. And are connected by transmission lines (shown by dotted lines). 8 is a changeover switch on the receiver side, which is composed of a pair of switches 81 and 82 for switching the polarity of the series circuit of the power source 9 and the load resistor 11 at the third and fourth terminals. In the block diagram shown in Figure 1 on ordination, the changeover switch 8, in which the measurement fluid by switching to select whether a liquid or gas, switches 81 and 82 shown are each S 1 -1, S 2 This is a case where the gas flow rate is measured when -1 is closed, and a voltage is applied to the output circuit 6 through the fourth terminal T 4 , the second terminal T 2 , and the diode D 1 , and the diode D 2 , The first terminal T 1 ,
Return to the load resistance 11 via the third terminal T 3 . In this case, the photosensitive switches P 3 and P 4 remain open without being responded, and therefore the feedback resistance of the amplifier 2 is only R 1 and the gain characteristic suitable for the gas flow rate range is the feedback resistance R 1.
Determined by 1 . Also in the case of the filter circuit 3, C 1 is selected as the capacitor capacity. The eddy signal has a level proportional to the fluid density and the square of the flow velocity. In the case of gas, the density is small and the flow velocity is large, so the amplifier gain is increased in the small flow region and the third-order low-pass filter is used in the large flow region. It is used to equalize the vortex signal level and to sufficiently attenuate outside the flow rate range to improve the S / N. On the other hand, in the case of liquid, since the density is high and the flow velocity is low, the amplifier gain is made small in the small basin, and the secondary to the third in the large basin.
The following low pass filter is used. Then, when switching the changeover switch 81, 82 to S 1 -2, S 2 -2, a case of measuring the liquid flow rate, a third terminal T 3 to the output circuit 6, the first terminal T 1, A voltage is applied via the light emitting diode D 3 and returns to the load resistor 11 via the light emitting diode D 4 and the second terminal T 2 . From these, the light emitting diode D 3 ,
D 4 emits light, and in response to this, light sensitive switches P 3 and P 4
Is closed, and the resistors R 1 and R 2 are connected in parallel on the amplifier 2 side to reduce the amplifier gain. In the filter circuit 3, the capacitors C 1 and C 2 are connected in parallel, and the cutoff frequency suitable for the liquid flow rate is reduced. The characteristics are obtained. Although the light emitting diodes D 3 and D 4 are shown in the figure, the number of these light emitting diodes is not limited to one, and a plurality of light emitting diodes may be arranged in parallel, and one of the light emitting diodes D 3 and D 4 is a normal diode. Instead of using either the diode D 1 or D 2 as a light emitting diode, the circuit element of the amplifier 2 or the filter circuit 3 may be selected according to the circuit characteristics. The point is that the changeover switch 8 on the receiver B side is switched. It suffices to be able to switch the light sensitive switches P 3 , P 4 or other light sensitive switches (not shown) that have the characteristics of the amplifier 1 and the band characteristic of the filter circuit 2 which are suitable for the liquid flow rate or the gas flow rate.
効果 叙上の如く、本考案の渦流量計回路によれば、渦信号の
２線伝送方式において、受信器側の切替スイッチの切替
えにより変換器側に設けられたダイオードブリッヂの光
ダイオードを発光させ、該発光ダイオードの発光に感応
する光スイッチを作動させるという遠隔切替え手段によ
り、液体用と気体用の２組の変換回路を必要とせず１組
の変換回路の回路要素を液体又は気体流量計測に適合し
た特性に切替えることができるので安価で、簡易小形の
２線伝送方式の渦流量計回路を提供することができる。Effect As described above, according to the vortex flowmeter circuit of the present invention, in the two-wire transmission system of the vortex signal, the photodiode of the diode bridge provided on the converter side is made to emit light by switching the changeover switch on the receiver side. By the remote switching means of activating an optical switch sensitive to the light emission of the light emitting diode, the circuit element of one conversion circuit can be used for liquid or gas flow rate measurement without the need for two conversion circuits for liquid and gas. It is possible to provide a simple and compact two-wire transmission type vortex flowmeter circuit because it is possible to switch to a suitable characteristic.
第１図は、本考案の渦流量計回路の原理を示すブロック
図である。 １……渦センサ、２……アンプ、３……フィルタ回路、
４……シュミット回路、５……演算回路、６……出力回
路、７……ダイオードブリッヂ、８……切替スイッチ、
９……電源、１１……負荷抵抗、Ｄ3，Ｄ4……発光ダイ
オード、Ｐ3，Ｐ4……光感応スイッチ。FIG. 1 is a block diagram showing the principle of the vortex flowmeter circuit of the present invention. 1 ... Vortex sensor, 2 ... Amplifier, 3 ... Filter circuit,
4 ... Schmidt circuit, 5 ... arithmetic circuit, 6 ... output circuit, 7 ... diode bridge, 8 ... changeover switch,
9 ...... power, 11 ...... load resistor, D 3, D 4 ...... emitting diodes, P 3, P 4 ...... photoresponsive switch.
Claims (1)
号を流量範囲の帯域で可変増幅する増幅回路と、渦信号
周波数のローパスフィルタ回路と、渦信号をパルス信号
に変換するパルス変換回路と、パルス信号を流量信号に
変換する変換回路と、該流量信号を２線伝送する第１、
第２端子を有する出力回路とからなる変換器および前記
第１、第２端子に接続する第３、第４端子と、該第３、
第４端子に直列接続する直流電源と負荷抵抗とからなる
受信器とで構成する渦流量計回路において、受信器側
は、直流電源と負荷抵抗との直列回路を第３、第４端子
の極性が反転するごとく替換え、変換器側は、第１、第
２端子の極性の何如にかかわらず出力回路に順方向の電
源を供給するダイオードブリッジを設け、且つ受信器側
の何れかの切替えで導通するダイオードを発光ダイオー
ドとし、該発光ダイオードの発光に応じて作動するスイ
ッチにより前記増幅回路のゲイン、およびフィルタ回路
におけるフィルタ定数を切替え、切替えにより液体と気
体流量計測に対応する特性をもつ変換器とすることを特
徴とする渦流量計回路。1. An amplification circuit for variably amplifying an approximate sine wave vortex signal output from a vortex sensor in a band of a flow rate range, a low-pass filter circuit for a vortex signal frequency, and a pulse conversion circuit for converting the vortex signal into a pulse signal. A conversion circuit for converting the pulse signal into a flow rate signal, and a first circuit for transmitting the flow rate signal by two wires,
A converter including an output circuit having a second terminal, and third and fourth terminals connected to the first and second terminals, and the third and fourth terminals.
In a vortex flowmeter circuit composed of a DC power supply connected in series with a fourth terminal and a receiver composed of a load resistance, the receiver side has a series circuit of a DC power supply and a load resistance with polarities of the third and fourth terminals. , The converter side is provided with a diode bridge that supplies forward power to the output circuit regardless of the polarities of the first and second terminals, and the converter side can be switched by either. A converter having a characteristic that corresponds to liquid and gas flow rate measurement by switching the conducting diode to a light emitting diode, and switching the gain of the amplifier circuit and the filter constant in the filter circuit by a switch that operates according to the light emission of the light emitting diode. A vortex flowmeter circuit characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2933889U JPH0626813Y2 (en) | 1989-03-15 | 1989-03-15 | Vortex flowmeter circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2933889U JPH0626813Y2 (en) | 1989-03-15 | 1989-03-15 | Vortex flowmeter circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02120024U JPH02120024U (en) | 1990-09-27 |
| JPH0626813Y2 true JPH0626813Y2 (en) | 1994-07-20 |
Family
ID=31253467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2933889U Expired - Lifetime JPH0626813Y2 (en) | 1989-03-15 | 1989-03-15 | Vortex flowmeter circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0626813Y2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109269579B (en) * | 2018-11-20 | 2024-04-16 | 中环天仪股份有限公司 | Intrinsic safety turbine signal detection circuit and implementation method |
-
1989
- 1989-03-15 JP JP2933889U patent/JPH0626813Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02120024U (en) | 1990-09-27 |
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