JP4292982B2 - Ultrasonic level meter - Google Patents

Ultrasonic level meter Download PDF

Info

Publication number
JP4292982B2
JP4292982B2 JP2003426499A JP2003426499A JP4292982B2 JP 4292982 B2 JP4292982 B2 JP 4292982B2 JP 2003426499 A JP2003426499 A JP 2003426499A JP 2003426499 A JP2003426499 A JP 2003426499A JP 4292982 B2 JP4292982 B2 JP 4292982B2
Authority
JP
Japan
Prior art keywords
ultrasonic
vibrator
cylindrical
transmission
level meter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2003426499A
Other languages
Japanese (ja)
Other versions
JP2005181269A (en
Inventor
明 片岡
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yokogawa Electric Corp
Original Assignee
Yokogawa Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yokogawa Electric Corp filed Critical Yokogawa Electric Corp
Priority to JP2003426499A priority Critical patent/JP4292982B2/en
Publication of JP2005181269A publication Critical patent/JP2005181269A/en
Application granted granted Critical
Publication of JP4292982B2 publication Critical patent/JP4292982B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)

Description

本発明は、超音波レベル計に関し、詳しくは超音波レベル計の超音波の音速を補正する機能を備えた超音波レベル計に関する。   The present invention relates to an ultrasonic level meter, and more particularly to an ultrasonic level meter having a function of correcting the speed of ultrasonic waves of an ultrasonic level meter.

従来技術における超音波レベル計は、図１１に示すように、測定対象物１１１が収容されている環境の温度を測定する温度センサ１１２と、温度センサ１１２で得られた温度情報により音速を演算する音速演算器１１３と、超音波を測定対象物１１１方向に発射すると共に、発射した超音波の反射した反射超音波を受信する機能を備えた送受信器１１４と、送受信器１１４の送信と受信を切り替える送／受切替器１１５と、超音波を送信するための送信回路１１６と、超音波を受信するための受信回路１１７と、受信回路１１７で受信した反射超音波の伝播時間を測定する伝播時間測定器１１８と、音速演算器１１３で得られた音速データに基づいて伝播時間測定器１１８で測定した伝播時間により測定対象物１１１までの距離を演算する距離／レベル演算器１１９と、測定対象物１１１までの演算して得られた距離データを出力する出力回路１２０と、からなる。   As shown in FIG. 11, the ultrasonic level meter according to the prior art calculates the sound velocity based on the temperature sensor 112 that measures the temperature of the environment in which the measurement object 111 is accommodated and the temperature information obtained by the temperature sensor 112. The sound speed calculator 113, a transmitter / receiver 114 that emits ultrasonic waves toward the measurement object 111, and a function of receiving reflected ultrasonic waves reflected from the emitted ultrasonic waves, and transmission / reception of the transmitter / receiver 114 are switched. Transmission / reception switch 115, transmission circuit 116 for transmitting ultrasonic waves, reception circuit 117 for receiving ultrasonic waves, and propagation time measurement for measuring the propagation time of reflected ultrasonic waves received by the reception circuit 117 A distance for calculating the distance to the measuring object 111 based on the propagation time measured by the propagation time measuring device 118 based on the sound speed data obtained by the sound device 118 and the sound speed computing unit 113. / Level calculator 119, an output circuit 120 for outputting the distance data obtained by calculation to the measurement object 111, made of.

このような構成からなる超音波レベル計において、送受信器１１４から発信した超音波パルスが測定対象物１１１表面に反射して送受信器１１４に戻ってくるまでの伝播時間より、対象物までの距離を測定する。   In the ultrasonic level meter having such a configuration, the distance to the object is determined from the propagation time until the ultrasonic pulse transmitted from the transmitter / receiver 114 is reflected on the surface of the measurement object 111 and returns to the transmitter / receiver 114. taking measurement.

伝播時間ｔと距離Ｌとの関係は次式による。
Ｌ＝Ｃ＊ｔ／２ 式（１）
ここで、Ｃ：空気中の超音波音速 The relationship between the propagation time t and the distance L is as follows.
L = C * t / 2 Formula (1)
Where C: ultrasonic speed of sound in the air

ここで、超音波の音速Ｃは温度によって変動するため、音速を補償する必要がある。
この補償手段として、温度センサ１１２で温度を測定して関係式より音速を算出する。
例えば、空気中での音速Ｃと温度Ｔの関係式は、次式となる。
Ｃ＝３３１.５＋０．６＊Ｔ 式（２） Here, since the sound speed C of the ultrasonic wave varies depending on the temperature, it is necessary to compensate the sound speed.
As this compensation means, the temperature is measured by the temperature sensor 112 and the sound velocity is calculated from the relational expression.
For example, the relational expression between the speed of sound C and the temperature T in the air is as follows.
C = 331.5 + 0.6 * T Formula (2)

このようにして、空気中の超音波の音速を得ることができるのであるが、測定環境のガス種類や濃度、温度が次々刻々変化している場合には、上記の関係式（式（１）、式（２））は一様ではないため、音速補償するのは困難であり、結果として測定誤差が出てしまうという問題がある。   In this way, the speed of sound of ultrasonic waves in the air can be obtained. However, when the gas type, concentration, and temperature of the measurement environment are constantly changing, the above relational expression (formula (1)) is obtained. Since the equation (2) is not uniform, it is difficult to compensate for the sound velocity, resulting in a measurement error.

この改善方法として、送受信器１１４と測定対象物１１１との間であって、予め定まった一定距離位置に反射板１２１を設置して、超音波の音速を測定し、この結果に基づいて超音波を補償するというものであり、その構成は、図１２に示すように、超音波を測定対象物１１１方向に発射すると共に、発射した超音波の反射した反射超音波を受信する機能を備えた送受信器１１４と、送受信器１１４と測定対象物１１１との間であって送受信器１１４から一定距離の位置に設けた反射板１２１と、送受信器１１４の送信と受信を切り替える送／受切替器１１５と、超音波を送信するための送信回路１１６と、超音波を受信するための受信回路１１７と、受信回路１１７で受信した反射超音波の伝播時間を測定する信号処理演算器１２２と、信号処理演算器１２２で得られた音速データに基づいて測定対象物１１１までの距離を演算する距離／レベル演算器１１９と、測定対象物１１１までの演算して得られた距離データを出力する出力回路１２０と、からなる。   As an improvement method, a reflection plate 121 is installed at a predetermined distance between the transmitter / receiver 114 and the measurement object 111, and the sound velocity of the ultrasonic wave is measured. Based on this result, the ultrasonic wave is measured. As shown in FIG. 12, the configuration is a transmission / reception having a function of emitting ultrasonic waves toward the measurement object 111 and receiving reflected ultrasonic waves reflected by the emitted ultrasonic waves. , A reflector 121 provided between the transmitter / receiver 114 and the measurement object 111 at a fixed distance from the transmitter / receiver 114, and a transmission / reception switch 115 for switching between transmission and reception of the transmitter / receiver 114, A transmitting circuit 116 for transmitting ultrasonic waves, a receiving circuit 117 for receiving ultrasonic waves, a signal processing calculator 122 for measuring the propagation time of reflected ultrasonic waves received by the receiving circuit 117, A distance / level calculator 119 that calculates the distance to the measurement object 111 based on the sound velocity data obtained by the processing calculator 122, and an output circuit that outputs the distance data obtained by calculation to the measurement object 111 120.

このように、超音波を送信及び受信する送受信器１１４の前面に送受信器１１４からの距離が既知（Ｌｍ）の反射板１２１を設置しておき、反射板１２１及び測定対象物１１１までのそれぞれの超音波伝播時間ｔｍ、ｔｘより測定対象物までの距離Ｌｘを測定することで、音速の変化によらず測定することができる。
Ｌｘ＝Ｌｍ＊（ｔｘ／ｔｍ） 式（３） As described above, the reflector 121 having a known distance (Lm) from the transmitter / receiver 114 is installed on the front surface of the transmitter / receiver 114 that transmits and receives ultrasonic waves, and each of the reflector 121 and the measurement object 111 is measured. By measuring the distance Lx to the measurement object from the ultrasonic propagation times tm and tx, the measurement can be performed regardless of the change in sound speed.
Lx = Lm * (tx / tm) Formula (3)

特開２００１−１６５７５３（第３頁〜４頁 第１図）Japanese Patent Laid-Open No. 2001-165753 (pages 3-4)

しかし、従来技術で説明した超音波流量計においては、測定範囲内に反射板を設置するため、設置場所の構造制限などで反射板が挿入できない場合や反射板が測定対象物に浸水した場合では音速測定ができないという問題がある。   However, in the ultrasonic flowmeter described in the prior art, since the reflector is installed within the measurement range, when the reflector cannot be inserted due to structural limitations of the installation location or when the reflector is immersed in the measurement object, There is a problem that the sound speed cannot be measured.

従って、測定対象物の影響を受けずに且つ温度の変化等の環境の変化を安定した状態で測定できる構成に解決しなければならない課題を有する。   Therefore, there is a problem that must be solved in a configuration that can measure a change in environment such as a change in temperature in a stable state without being affected by the measurement object.

上記課題を解決するために、本発明の超音波レベル計は、次に示す構成にすることである。   In order to solve the above problems, the ultrasonic level meter of the present invention is configured as follows.

（１）超音波レベル計は、超音波検出器先端に備えた送受波器より発信した超音波の測定対象物までの伝播時間から測定対象物までの距離を計測する超音波レベル計であって、前記超音波検出器の側面に空気中の超音波の音速を測定する超音波測定手段を備え、
前記超音波測定手段は、前記超音波検出器側面に備えた円筒振動子と、前記超音波検出器の外周位置に備えた段差付き円筒管と、周波数を可変で円筒振動子を駆動する送信回路と、前記円筒管の段差の凹面および凸面で反射して戻ってきた超音波信号を受信する受信回路と、前記受信回路で受信した超音波信号を時間で積分する積分器と、前記送信回路から送信する超音波の各送信周波数と前記積分器で生成された各積分データと前記円筒振動子の送受信効率の周波数特性とを格納するメモリと、積分データに前記円筒振動子の送受信効率の周波数特性を除算して振動子影響を取り除き、この除算を行った各積分データの極大点と極小点との周波数間隔を求めて、この周波数間隔と前記段差とから音速を算出する演算器と、を備えたことを特徴とする。
（２）前記円筒振動子が、共振周波数の異なる複数の振動子を有することを特徴とする（１）に記載の超音波レベル計。
（３）前記円筒振動子と前記円筒管のかわりに、板状振動子と段差付きの反射板にしたことを特徴とする（１）に記載の超音波レベル計。
（４）前記円筒振動子のかわりに、厚み方向で被測定対象物に超音波を送受信する円板振動子の径方向の超音波を利用するようにしたことを特徴とする（１）に記載の超音波レベル計。
(1) The ultrasonic level meter is an ultrasonic level meter that measures the distance from the propagation time to the measurement object of the ultrasonic wave transmitted from the transducer provided at the tip of the ultrasonic detector to the measurement object. An ultrasonic measurement means for measuring the speed of sound in the air on the side of the ultrasonic detector ;
The ultrasonic measurement means includes a cylindrical vibrator provided on a side surface of the ultrasonic detector, a stepped cylindrical tube provided at an outer peripheral position of the ultrasonic detector, and a transmission circuit that drives the cylindrical vibrator with a variable frequency. A reception circuit that receives the ultrasonic signal reflected and returned by the concave and convex surfaces of the step of the cylindrical tube, an integrator that integrates the ultrasonic signal received by the reception circuit with time, and the transmission circuit Memory for storing each transmission frequency of ultrasonic waves to be transmitted, each integration data generated by the integrator, and frequency characteristics of transmission / reception efficiency of the cylindrical vibrator, and frequency characteristics of transmission / reception efficiency of the cylindrical vibrator in the integration data And a calculator for calculating the sound speed from the frequency interval and the step, by obtaining the frequency interval between the local maximum point and the local minimum point of each integrated data obtained by the division. Special To.
( 2 ) The ultrasonic level meter according to ( 1 ), wherein the cylindrical vibrator has a plurality of vibrators having different resonance frequencies.
( 3 ) The ultrasonic level meter according to ( 1 ), wherein instead of the cylindrical vibrator and the cylindrical tube, a plate-like vibrator and a reflector with a step are used.
( 4 ) Instead of the cylindrical vibrator, ultrasonic waves in a radial direction of a disk vibrator that transmits / receives ultrasonic waves to / from an object to be measured in the thickness direction are used ( 1 ). Ultrasonic level meter.

以上説明したことから明らかなように、本発明によれば、超音波センサ内部の構成で音速を測定するため、設置環境の制限や測定対象物のレベルの影響をうけずに、小型で安定に音速を補償することができる。   As is apparent from the above description, according to the present invention, the speed of sound is measured with the internal configuration of the ultrasonic sensor, so that it is small and stable without being affected by the restriction of the installation environment or the level of the measurement object. The speed of sound can be compensated.

以下、本発明の超音波レベル計の実施形態について、図面を用いて詳細に説明する。   Hereinafter, embodiments of the ultrasonic level meter of the present invention will be described in detail with reference to the drawings.

本発明の超音波レベル計は、図１に示すように、測定対象物方向に向いて設置されている超音波検出器１１と、この超音波検出器１１の先端に測定対象物方向に超音波を発射する送受信器１２を備え、超音波検出器１１の側面に空気中の超音波の音速を測定する超音波測定手段１３を備えた構成になっている。   As shown in FIG. 1, the ultrasonic level meter of the present invention has an ultrasonic detector 11 installed in the direction of the measurement object, and an ultrasonic wave in the direction of the measurement object at the tip of the ultrasonic detector 11. The transmitter / receiver 12 emits the ultrasonic wave, and the ultrasonic detector 11 is provided on the side surface of the ultrasonic detector 11 to measure the sound velocity of the ultrasonic wave in the air.

送受信器１２は、超音波検出器１１先端の開口部分に配置されており、吸音材１４を挟んで振動子１５、及び音響整合層１６とからなる。   The transmitter / receiver 12 is disposed in an opening portion at the tip of the ultrasonic detector 11 and includes a vibrator 15 and an acoustic matching layer 16 with a sound absorbing material 14 interposed therebetween.

超音波測定手段１３は、図１及び図２に示すように、超音波検出器１１の側面に備えた円筒振動子１７と、超音波検出器１１を囲む一定位置に、内側内周に均等の凹凸１８，１９の段差Ｌｄを設けた円筒管２０とを備えた構成になっている。   As shown in FIGS. 1 and 2, the ultrasonic measurement means 13 has a cylindrical vibrator 17 provided on the side surface of the ultrasonic detector 11 and a fixed position surrounding the ultrasonic detector 11, and the inner circumference is evenly distributed. It has a configuration including a cylindrical tube 20 provided with a step Ld of the irregularities 18 and 19.

そして、これらの送受信器１２及び超音波測定手段１３における回路構成は、図３に示すように、超音波を測定対象物２１方向に発射すると共に、発射した超音波の反射した反射超音波を受信する機能を備えた送受信器１２と、送受信器１２の送信と受信を切り替える送／受切替器２２と、超音波を送信するための第１の送信回路２３と、超音波を受信するための第１の受信回路２４と、第１の受信回路２４で受信した反射超音波の伝播時間を測定する伝播時間測定器２５と、演算器３２で得られた音速データに基づいて測定対象物２１までの距離を演算する距離／レベル演算器２６と、測定対象物２１までの演算して得られた距離データを出力する出力回路２７と、円筒管２０に向けて超音波を発射すると共に、その発射した超音波の反射超音波を受信する円筒振動子１７と、円筒振動子１７から発射する超音波又は受信する超音波を切り替える送／受切替器２８と、超音波を発射させる第２の送信回路２９と、超音波を受信するための第２の受信回路３０と、受信した超音波を積分する積分器３１と、積分した超音波信号を演算する演算器３２と、演算した結果を蓄積するメモリ３３と、から大略構成されている。   As shown in FIG. 3, the circuit configuration of the transceiver 12 and the ultrasonic measurement unit 13 emits ultrasonic waves toward the measurement object 21 and receives reflected ultrasonic waves reflected by the emitted ultrasonic waves. A transmitter / receiver 12 having a function to transmit, a transmission / reception switch 22 for switching between transmission and reception of the transmitter / receiver 12, a first transmission circuit 23 for transmitting ultrasonic waves, and a first for receiving ultrasonic waves 1 receiving circuit 24, a propagation time measuring device 25 for measuring the propagation time of the reflected ultrasonic wave received by the first receiving circuit 24, and the measurement object 21 based on the sound velocity data obtained by the computing unit 32. A distance / level calculator 26 that calculates the distance, an output circuit 27 that outputs the distance data obtained by the calculation up to the measurement object 21, and an ultrasonic wave toward the cylindrical tube 20 are emitted. Ultrasonic reflection A cylindrical vibrator 17 that receives sound waves, a transmission / reception switch 28 that switches between ultrasonic waves emitted from the cylindrical vibrator 17 or received ultrasonic waves, a second transmission circuit 29 that emits ultrasonic waves, and ultrasonic waves. The second receiving circuit 30 for receiving, an integrator 31 for integrating the received ultrasonic wave, a calculator 32 for calculating the integrated ultrasonic signal, and a memory 33 for storing the calculated result are roughly configured. Has been.

このような構成からなる超音波レベル計において、円筒振動子１７の周波数特性は、送受信周波数を広範囲で可変で動作できるように比較的小さいＱを持つ構成になっており、いま、円筒振動子１７から周波数ｆの超音波バースト波を円筒管２０に向けて発信し、円筒管２０の段差の凹凸１８，１９で反射して戻ってくるエコーを円筒振動子１７で検出する。１回送信した超音波バースト波は、図５に示すように、減衰しながら円筒振動子１７と円筒管２０との間を往復する。この結果、バースト波エコーの受信信号は時間とともに減衰した特性となる。
この信号Ｓを積分器３１で積分し、得られた積分データＩ'と送信周波数ｆとをメモリ３３に格納する。
次に、送信周波数を少し変えて、同様に送受信したときの積分データと周波数をメモリ３３に格納する。これを繰り返した結果、メモリ３３には送信周波数ｆと積分データI'のテーブルが格納される。ここで、図６に示すように、送信周波数の動作範囲は、円筒振動子１７固有の共振周波数ｆ０を中心とした周波数可変幅で測定を行なう。なお、円筒振動子１７の送受信効率のｆ特性はｆ０を最大値とした凸形状となるので、積分データI'から振動子特性を除くため、予め格納しておいた円筒振動子１７のｆ特性を除算演算を行った積分データIを演算しメモリ３３に格納する。 In the ultrasonic level meter having such a configuration, the frequency characteristic of the cylindrical vibrator 17 has a relatively small Q so that the transmission / reception frequency can be varied over a wide range. Then, an ultrasonic burst wave having a frequency f is transmitted toward the cylindrical tube 20, and echoes reflected and returned by the unevenness 18 and 19 of the step of the cylindrical tube 20 are detected by the cylindrical vibrator 17. As shown in FIG. 5, the ultrasonic burst wave transmitted once reciprocates between the cylindrical vibrator 17 and the cylindrical tube 20 while being attenuated. As a result, the received signal of the burst wave echo has a characteristic that is attenuated with time.
This signal S is integrated by the integrator 31, and the obtained integration data I ′ and transmission frequency f are stored in the memory 33.
Next, the transmission frequency is changed slightly, and the integration data and the frequency when similarly transmitted and received are stored in the memory 33. As a result of repeating this, the memory 33 stores a table of the transmission frequency f and the integral data I ′. Here, as shown in FIG. 6, the operating range of the transmission frequency is measured with a frequency variable width centered on the resonance frequency f 0 unique to the cylindrical vibrator 17. Since the f characteristic of the transmission / reception efficiency of the cylindrical vibrator 17 has a convex shape with f0 as the maximum value, the f characteristic of the cylindrical vibrator 17 stored in advance is used to exclude the vibrator characteristic from the integral data I ′. Is calculated and stored in the memory 33.

積分データIと送信周波数ｆの関係は、図７に示すように、周波数ｆ（ｉ）を境にして周波数ｆ（ｉ−１）、ｆ（ｉ＋１）の２つの大きなやまになる。
即ち、円筒振動子１７から超音波パルスを円筒管２０に向けて送信されると、超音波パルスは円筒管２０の段差の各凹凸１８、１９で反射して円筒振動子１７に帰ってくる。ここで、送信超音波波長λと円筒管２０の凹凸１８、１９の段差Ｌｄの関係が、次式の条件を満たすと、円筒振動子１７に戻ってくるエコーの全円周総音圧は、極大あるいは極小点となる。
Ｌｄ＝λｎ*ｎ/４ 式（４）
ここで、
ｎ＝１、３、５・・・のとき極小、ｎ＝２、４、６・・・のとき極大となる。
なぜならば、図４に示すように、凹凸１８、１９の段差が１/４・λで、ｎが奇数の時には凹凸１８、１９で反射したエコーのそれぞれの位相は反転するので相殺され、ｎが偶数のときは同位相となりエコー音圧は合算されるためである。 As shown in FIG. 7, the relationship between the integral data I and the transmission frequency f becomes two large mountains of frequencies f (i−1) and f (i + 1) with the frequency f (i) as a boundary.
That is, when an ultrasonic pulse is transmitted from the cylindrical vibrator 17 toward the cylindrical tube 20, the ultrasonic pulse is reflected by the irregularities 18 and 19 of the step of the cylindrical tube 20 and returns to the cylindrical vibrator 17. Here, if the relationship between the transmission ultrasonic wavelength λ and the step Ld of the projections and depressions 18 and 19 of the cylindrical tube 20 satisfies the following equation, the total circumferential sound pressure of the echoes returning to the cylindrical vibrator 17 is It becomes the maximum or minimum point.
Ld = λn * n / 4 Formula (4)
here,
When n = 1, 3, 5,..., the minimum is obtained, and when n = 2, 4, 6,.
This is because, as shown in FIG. 4, when the unevenness 18 and 19 has a step of 1/4 · λ and n is an odd number, the phases of echoes reflected by the unevenness 18 and 19 are reversed and cancel each other. This is because when the number is even, the phase is the same and the echo sound pressure is added.

又、超音波波長λと周波数ｆの関係は次式、
λｎ＝Ｃ/ｆｎ 式（５）
ここでＣは超音波の音速度
となるので、周波数変化に対して、音圧は極大と極小を交互に現れる特性となる。
この総音圧の極大/極小と周波数の関係は、前記の積分データＩと送信周波数ｆの関係と同等である。 The relationship between the ultrasonic wavelength λ and the frequency f is as follows:
λn = C / fn (5)
Here, C is the sound velocity of the ultrasonic wave, so that the sound pressure has a characteristic in which a maximum and a minimum appear alternately with respect to a frequency change.
The relationship between the maximum / minimum total sound pressure and the frequency is equivalent to the relationship between the integral data I and the transmission frequency f.

[送信周波数ｆと極大/極小点の関係]
（４）、（５）式より次式が得られる。
ｆｎ＝ｎ/４*Ｃ/Ｌｄ 式（６）
隣り合う極の周波数間隔Δｆは次式となる。
Δｆ＝ｆ(i+1)-f(i)＝Ｃ/（4*Ｌｄ） 式（７）
式（７）を変形すると、
Ｃ＝4*Ｌｄ*Δｆ 式（７'）
となり、隣り合う極の周波数間隔Δｆが測定できれば、凹凸１８，１９の段差Ｌｄは既知なので音速Ｃを求められる。 [Relationship between transmission frequency f and maximum / minimum points]
The following equation is obtained from equations (4) and (5).
fn = n / 4 * C / Ld Formula (6)
The frequency interval Δf between adjacent poles is as follows.
Δf = f (i + 1) −f (i) = C / (4 * Ld) Equation (7)
When formula (7) is transformed,
C = 4 * Ld * Δf Formula (7 ′)
If the frequency interval Δf between adjacent poles can be measured, the sound velocity C can be obtained because the step Ld between the irregularities 18 and 19 is known.

メモリ３３に格納された送信周波数ｆと積分データＩから隣り合う極の周波数間隔Δｆを求める、実測された各送信周波数ｆは離散値であるため、補間近似曲線より極となる周波数を求め、隣り合う極の周波数間隔Δｆを算出する。
現在の音速Ｃが求められれば、従来技術で説明した式（１）の伝播時間ｔを算出することで、測定対象物までの距離Ｌを求めることができるのである。 The frequency interval Δf between adjacent poles is obtained from the transmission frequency f stored in the memory 33 and the integration data I. Since each measured transmission frequency f is a discrete value, the frequency that becomes the pole is obtained from the interpolation approximation curve. The frequency interval Δf of the matching poles is calculated.
If the current sound velocity C is obtained, the distance L to the measurement object can be obtained by calculating the propagation time t of the equation (1) described in the prior art.

このようにして、先ず、超音波検出器１１に設けた円筒振動子１７と円筒管２０を使用して、超音波の音速を求めるようにしたことで、測定対象物２１の影響を受けずに且つ温度の変化等の環境の変化を安定した状態で測定することができるのである。   In this way, first, by using the cylindrical vibrator 17 and the cylindrical tube 20 provided in the ultrasonic detector 11, the sound velocity of the ultrasonic wave is obtained, so that it is not affected by the measurement object 21. In addition, environmental changes such as temperature changes can be measured in a stable state.

図８は、超音波測定手段１３を形成する円筒振動子１７と円筒管２０との関係における変形例を示したものであり、円筒管２０の内周に板厚Ｌｄの板で、穴を設けた穴付板３４を嵌め込んだ構造にしてもよい。   FIG. 8 shows a modification of the relationship between the cylindrical vibrator 17 forming the ultrasonic measurement means 13 and the cylindrical tube 20. A hole is provided in the inner periphery of the cylindrical tube 20 with a plate having a plate thickness Ld. A structure with a holed plate 34 fitted therein may be used.

又、他の変形例として、円筒振動子と円筒管とを超音波検出器から分離して独立した構成にしてもよい。   As another modification, the cylindrical vibrator and the cylindrical tube may be separated from the ultrasonic detector and configured independently.

更に、他の変形例として、図９に示すように、円筒振動子と円筒管の関係は、円筒振動子のかわりに、吸音材３５で封止されている板状振動子３６にすると共に、円筒管のかわりに、板状振動子３６から発射された超音波を受ける、凹凸の段差がある段差部３７を設けるようにしてもよい。   Furthermore, as another modification example, as shown in FIG. 9, the relationship between the cylindrical vibrator and the cylindrical tube is a plate-like vibrator 36 sealed with a sound absorbing material 35 instead of the cylindrical vibrator, Instead of the cylindrical tube, a stepped portion 37 having an uneven step for receiving ultrasonic waves emitted from the plate-like vibrator 36 may be provided.

また、円筒振動子は、円筒状でなくとも、円周方向に複数に分離された円弧状の振動子を組み合わせた構成でもよい。   Further, the cylindrical vibrator may not be cylindrical, but may be configured by combining arcuate vibrators separated into a plurality in the circumferential direction.

さらに、円筒振動子の共振周波数が相異なる複数の振動子を並べた構成でもよい。   Further, a configuration in which a plurality of vibrators having different resonance frequencies of the cylindrical vibrator are arranged may be employed.

また、円筒振動子と円筒管とにおいて、図１０に示すように、円筒振動子を使わず、ノズル１１先端に設けた送受信器１２の円板振動子１５のみとして、厚み方向で測定対象物までの超音波エコー伝播時間を測定し、径方向で音速測定を行うようにしてもよい。このようにすると、円筒振動子を取り付ける必要がなくなる。   Further, in the cylindrical vibrator and the cylindrical tube, as shown in FIG. 10, the cylindrical vibrator is not used and only the disk vibrator 15 of the transmitter / receiver 12 provided at the tip of the nozzle 11 is used to reach the measurement object in the thickness direction. The ultrasonic echo propagation time may be measured, and the sound velocity may be measured in the radial direction. In this way, it is not necessary to attach a cylindrical vibrator.

更に、振動子の送受信効率と周波数特性データを、積分データI'に除算するかわりに、送信強度を周波数特性に応じて変化させて補償する構成にしてもよい。   Further, instead of dividing the transmission / reception efficiency and frequency characteristic data of the vibrator into the integral data I ′, the transmission intensity may be changed according to the frequency characteristic to compensate.

超音波を利用して測定対象物までの距離を算出する超音波レベル計において、超音波を発射しする超音波検出器に超音波の音速を測定する測定手段を備えることで、測定対象物の温度等の環境の変化に追随した超音波による測定対象物までの距離を正確に測定することができる超音波レベル計を提供する。   In an ultrasonic level meter that calculates the distance to an object to be measured using ultrasonic waves, the ultrasonic detector that emits the ultrasonic wave is provided with a measuring unit that measures the speed of sound of the ultrasonic object. Provided is an ultrasonic level meter capable of accurately measuring a distance to an object to be measured by an ultrasonic wave following a change in environment such as temperature.

本願発明の超音波レベル計の構成を略示的に示した説明図である。It is explanatory drawing which showed schematically the structure of the ultrasonic level meter of this invention. 同、超音波レベル計を底面からみた説明図である。It is explanatory drawing which looked at the ultrasonic level meter from the bottom. 同、超音波レベル計の構成を示すブロック図である。It is a block diagram which shows the structure of an ultrasonic level meter similarly. 同、段差の凹凸部でそれぞれ反射して振動円筒面に到達した超音波音圧波形図である。FIG. 6 is an ultrasonic sound pressure waveform diagram that is reflected by the uneven portions of the steps and reaches the vibrating cylindrical surface. 同、超音波エコーの受信信号の時間特性を示したグラフである。4 is a graph showing time characteristics of a reception signal of an ultrasonic echo. 同、円筒振動子の送受信効率の周波数特性を示したグラフである。4 is a graph showing frequency characteristics of transmission / reception efficiency of a cylindrical vibrator. 同、積分データと送信周波数の測定データを示すグラフである。It is a graph which shows the integration data and the measurement data of transmission frequency similarly. 同、円筒管の段差の変わりに、板厚がＬｄの穴付板を超音波検出器の表面に取り付けた構造を示す変形例である。In the same manner, it is a modified example showing a structure in which a plate with a hole having a thickness Ld is attached to the surface of an ultrasonic detector instead of the step of the cylindrical tube. 同、円筒振動子と円筒管のかわりに、板状振動子と段差を持った板の構成した変形例である。This is a modification in which a plate having a step and a step is formed instead of a cylindrical vibrator and a cylindrical tube. 同、測定対象物の距離を測るための円板振動子を超音波の音速をも測定するようにした変形例である。In the same manner, the disk vibrator for measuring the distance of the object to be measured is a modification in which the speed of ultrasonic waves is also measured. 従来技術における超音波レベル計の構成図である。It is a block diagram of the ultrasonic level meter in a prior art. 従来技術における音速補償方法を示したブロック図である。It is the block diagram which showed the sound speed compensation method in a prior art.

符号の説明Explanation of symbols

１１ 超音波検出器
１２ 送受信器
１３ 超音波測定手段
１４ 吸音材
１５ 振動子
１６ 音響整合層
１７ 円筒振動子
１８ 凹
１９ 凸
２０ 円筒管
２１ 測定対象物
２２ 送／受切替器
２３ 第１の送信回路
２４ 第１の受信回路
２５ 伝播時間測定器
２６ 距離／レベル演算器
２７ 出力回路
２８ 送／受切替器
２９ 第２の送信回路
３０ 第２の受信回路
３１ 積分器
３２ 演算器
３３ メモリ
３４ 穴付板
３５ 吸音材
３６ 板状振動子
３７ 段差部。
DESCRIPTION OF SYMBOLS 11 Ultrasonic detector 12 Transceiver 13 Ultrasonic measuring means 14 Sound absorbing material 15 Vibrator 16 Acoustic matching layer 17 Cylindrical vibrator 18 Concave 19 Convex 20 Cylindrical tube 21 Measuring object 22 Transmission / reception switch 23 First transmission circuit 24 first receiver circuit 25 propagation time measuring device 26 distance / level calculator 27 output circuit 28 transmission / reception switch 29 second transmitter circuit 30 second receiver circuit 31 integrator 32 calculator 33 memory 34 plate with hole 35 Sound-absorbing material 36 Plate-like vibrator 37 Stepped portion.

Claims (4)

超音波検出器先端に備えた送受波器より発信した超音波の測定対象物までの伝播時間から測定対象物までの距離を計測する超音波レベル計であって、
前記超音波検出器の側面に空気中の超音波の音速を測定する超音波測定手段を備え、
前記超音波測定手段は、
前記超音波検出器側面に備えた円筒振動子と、
前記超音波検出器の外周位置に備えた段差付き円筒管と、
周波数を可変で円筒振動子を駆動する送信回路と、
前記円筒管の段差の凹面および凸面で反射して戻ってきた超音波信号を受信する受信回路と、
前記受信回路で受信した超音波信号を時間で積分する積分器と、
前記送信回路から送信する超音波の各送信周波数と前記積分器で生成された各積分データと前記円筒振動子の送受信効率の周波数特性とを格納するメモリと、
積分データに前記円筒振動子の送受信効率の周波数特性を除算して振動子影響を取り除き、この除算を行った各積分データの極大点と極小点との周波数間隔を求めて、この周波数間隔と前記段差とから音速を算出する演算器と、
を備えたことを特徴とする超音波レベル計。 An ultrasonic level meter that measures the distance from the propagation time to the measurement object of the ultrasonic wave transmitted from the transducer provided at the tip of the ultrasonic detector to the measurement object,
An ultrasonic measuring means for measuring the speed of sound in the air on the side of the ultrasonic detector ;
The ultrasonic measurement means includes
A cylindrical vibrator provided on the side of the ultrasonic detector;
A cylindrical tube with a step provided at the outer peripheral position of the ultrasonic detector;
A transmission circuit that drives a cylindrical vibrator with a variable frequency;
A receiving circuit for receiving an ultrasonic signal reflected and returned by the concave and convex surfaces of the step of the cylindrical tube;
An integrator for integrating the ultrasonic signal received by the receiving circuit with time;
A memory for storing each transmission frequency of ultrasonic waves transmitted from the transmission circuit, each integration data generated by the integrator, and frequency characteristics of transmission / reception efficiency of the cylindrical vibrator;
Dividing the frequency characteristics of the transmission / reception efficiency of the cylindrical vibrator into the integral data to remove the influence of the vibrator, obtaining the frequency interval between the maximum point and the minimum point of each integral data obtained by the division, An arithmetic unit for calculating the sound speed from the step,
An ultrasonic level meter characterized by comprising: 前記円筒振動子が、共振周波数の異なる複数の振動子を有することを特徴とする請求項１に記載の超音波レベル計。 The ultrasonic level meter according to claim 1 , wherein the cylindrical vibrator has a plurality of vibrators having different resonance frequencies. 前記円筒振動子と前記円筒管のかわりに、板状振動子と段差付きの反射板にしたことを特徴とする請求項１に記載の超音波レベル計。 2. The ultrasonic level meter according to claim 1 , wherein instead of the cylindrical vibrator and the cylindrical tube, a plate-like vibrator and a reflector with a step are used. 前記円筒振動子のかわりに、厚み方向で測定対象物に超音波を送受信する円板振動子の径方向の超音波を利用するようにしたことを特徴とする請求項１に記載の超音波レベル計。 The ultrasonic level according to claim 1 , wherein, instead of the cylindrical vibrator, ultrasonic waves in a radial direction of a disk vibrator that transmits and receives ultrasonic waves to and from a measurement object in the thickness direction are used. Total.
JP2003426499A 2003-12-24 2003-12-24 Ultrasonic level meter Expired - Fee Related JP4292982B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003426499A JP4292982B2 (en) 2003-12-24 2003-12-24 Ultrasonic level meter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003426499A JP4292982B2 (en) 2003-12-24 2003-12-24 Ultrasonic level meter

Publications (2)

Publication Number Publication Date
JP2005181269A JP2005181269A (en) 2005-07-07
JP4292982B2 true JP4292982B2 (en) 2009-07-08

Family

ID=34786018

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003426499A Expired - Fee Related JP4292982B2 (en) 2003-12-24 2003-12-24 Ultrasonic level meter

Country Status (1)

Country Link
JP (1) JP4292982B2 (en)

Also Published As

Publication number Publication date
JP2005181269A (en) 2005-07-07

Similar Documents

Publication Publication Date Title
JP3810430B2 (en) Ultrasonic ranging device
CN110199179B (en) Ultrasonic flowmeter and method for detecting a throughflow parameter
US11215489B2 (en) Apparatus and method for measuring the flow velocity of a fluid in a pipe
JP3129563B2 (en) Ultrasonic measurement method and device
JP2013507624A (en) Method and apparatus for improved ultrasonic propagation time difference measurement
WO2013183292A1 (en) Ultrasonic echo sounder transducer and ultrasonic flow meter equipped with same
EP3710795B1 (en) Device and method for detecting deposition layers in a conduit conducting a liquid or a soft medium and/or for level detection
JPS639169B2 (en)
JPH1054872A (en) Ultrasonic distance meter
JP4292982B2 (en) Ultrasonic level meter
RU2692824C1 (en) Ultrasonic flow rate measuring device and method of determining flow rate
KR20170033263A (en) Ultrasonic flow meter
JP2005337848A (en) Ultrasonic distance measuring device
CA2392062A1 (en) Method for pulse offset calibration in time of flight ranging systems
JPH11351928A (en) Flowmetr and flow rate measuring method
Tanaka et al. Doppler shift equation and measurement errors affected by spatial variation of the speed of sound in sea water
JP2000298045A5 (en)
JP3036172B2 (en) Liquid level detector in pressure vessel
JPH05180676A (en) Flow rate measuring device
RU2284015C2 (en) Method and device for measuring flux discharge
JP2005127722A (en) Ultrasonic level gage
JP2000298047A (en) Ultrasonic flow meter
JP2006153477A (en) Distance measuring apparatus and method
RU2692409C1 (en) Method of measuring liquid level
JP2853508B2 (en) Gas flow meter

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20060703

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20080612

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20080722

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20090106

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20090120

A911 Transfer to examiner for re-examination before appeal (zenchi)

Free format text: JAPANESE INTERMEDIATE CODE: A911

Effective date: 20090225

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20090317

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20090330

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120417

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120417

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130417

Year of fee payment: 4

LAPS Cancellation because of no payment of annual fees