JP5049689B2

JP5049689B2 - Ultrasonic flow meter

Info

Publication number: JP5049689B2
Application number: JP2007203818A
Authority: JP
Inventors: 保小林
Original assignee: Tokyo Keiso Co Ltd
Current assignee: Tokyo Keiso Co Ltd
Priority date: 2007-08-06
Filing date: 2007-08-06
Publication date: 2012-10-17
Anticipated expiration: 2027-08-06
Also published as: JP2009041912A

Description

本発明は、角管から成る測定用管体内に超音波反射率を制御した超音波反射体を設け、精度の良い測定を可能とした超音波流量計に関するものである。 The present invention relates to an ultrasonic flowmeter in which an ultrasonic reflector having a controlled ultrasonic reflectivity is provided in a measuring tube made of a square tube to enable accurate measurement.

一般に超音波流量計では、所謂時間差方式が実用性の高い流量計として使用されている。通常では、円管の上流側及び下流側に超音波送受信器を設置し、上流向け及び下流向け伝播時間の差から管内流流量を測定しているが、超音波ビームが管軸を通る簡単な構成では、流体の粘度の影響を受けることが知られている。特殊な例としては、２つの超音波ビームを断面半径を垂直に２分する位置に取り付けるタイプも使用され、この場合に軸対称流では流速分布誤差が少ない。 In general, in an ultrasonic flow meter, a so-called time difference method is used as a highly practical flow meter. Normally, ultrasonic transmitters / receivers are installed upstream and downstream of a circular pipe, and the flow rate in the pipe is measured from the difference in propagation time upstream and downstream. It is known that the configuration is affected by the viscosity of the fluid. As a special example, there is also used a type in which two ultrasonic beams are attached at a position where the cross-sectional radius is vertically divided into two. In this case, the flow velocity distribution error is small in the axially symmetric flow.

一般に、精度の良い測定をするためには、超音波ビームの伝播距離を長くすることが時間差が大きくなるので望ましい。大径の流体管路においては、管内面に超音波反射体を配置するなどして、伝播距離を大きくすることも可能である。 Generally, in order to perform measurement with high accuracy, it is desirable to increase the propagation distance of the ultrasonic beam because the time difference increases. In a large-diameter fluid conduit, the propagation distance can be increased by arranging an ultrasonic reflector on the inner surface of the tube.

しかし、小径の管体においては内部に超音波反射体を配置することが困難である。 However, it is difficult to arrange an ultrasonic reflector inside a small-diameter tube.

本発明の目的は、上述の問題点を解決して、構造が簡単であり、細管においても適用できる超音波流量計を提供することにある。 An object of the present invention is to solve the above-described problems, and to provide an ultrasonic flowmeter that has a simple structure and can be applied to a thin tube.

上記目的を達成するための本発明に係る超音波流量計は、測定流体を流す角管から成る測定用管体のｌつの面の流れ方向の上流側と下流側に、少なくとも１対の超音波送受信器を設置すると共に、前記管体内の前記超音波送受信器の取付面と対向する面上に周囲の管内面よりも超音波反射率が大きい超音波反射体を配置し、前記上流側又は下流側の超音波送受信器から発信した超音波ビームが前記超音波反射体で反射して前記下流側又は上流側の前記超音波送受信器に伝播する超音波流量計であって、前記超音波反射体の前記管体の管軸方向の長さを管軸に直交する方向に沿って変化させることにより、前記超音波反射体の前記管体の管軸と直交する方向の超音波反射率の分布を調整し、前記超音波ビームの振幅分布が前記管体内で均等化するようにしたことを特徴とする。
また、本発明に係る超音波流量計は、測定流体を流す角管から成る測定用管体のｌつの面の流れ方向の上流側と下流側に、少なくとも１対の超音波送受信器を設置すると共に、前記管体内の前記超音波送受信器の取付面と対向する面上に周囲の管内面よりも超音波反射率が大きい超音波反射体を配置し、前記上流側又は下流側の超音波送受信器から発信した超音波ビームが前記超音波反射体で反射して前記下流側又は上流側の前記超音波送受信器に伝播する超音波流量計であって、前記超音波反射体の表面粗度を管軸に直交する方向に沿って変化させることにより、前記超音波反射体の前記管体の管軸と直交する方向の超音波反射率の分布を調整し、前記超音波ビームの振幅分布が前記管体内で均等化するようにしたことを特徴とする。
更に、本発明に係る超音波流量計は、測定流体を流す角管から成る測定用管体のｌつの面の流れ方向の上流側と下流側に、少なくとも１対の超音波送受信器を設置すると共に、前記管体内の前記超音波送受信器の取付面と対向する面上に周囲の管内面よりも超音波反射率が大きい超音波反射体を配置し、前記上流側又は下流側の超音波送受信器から発信した超音波ビームが前記超音波反射体で反射して前記下流側又は上流側の前記超音波送受信器に伝播する超音波流量計であって、前記超音波反射体の取付面に対する傾きを管軸に直交する方向に沿って変化させることにより、前記超音波反射体の前記管体の管軸と直交する方向の超音波反射率の分布を調整し、前記超音波ビームの振幅分布が前記管体内で均等化するようにしたことを特徴とする。 In order to achieve the above object, an ultrasonic flowmeter according to the present invention includes at least one pair of ultrasonic waves on the upstream side and the downstream side in the flow direction of one surface of a measurement tube body including a square tube through which a measurement fluid flows. The transmitter / receiver is installed, and an ultrasonic reflector having a higher ultrasonic reflectivity than the inner surface of the surrounding tube is disposed on the surface facing the mounting surface of the ultrasonic transmitter / receiver in the tube, and the upstream side or the downstream side An ultrasonic flowmeter in which an ultrasonic beam transmitted from an ultrasonic transmitter / receiver on the side is reflected by the ultrasonic reflector and propagates to the ultrasonic transmitter / receiver on the downstream side or the upstream side, and the ultrasonic reflector By changing the length of the tube body in the tube axis direction along the direction orthogonal to the tube axis, the distribution of the ultrasonic reflectance of the ultrasonic reflector in the direction orthogonal to the tube axis of the tube body is changed. The amplitude distribution of the ultrasonic beam is equalized in the tube Characterized in that way the.
In the ultrasonic flowmeter according to the present invention, at least one pair of ultrasonic transmitters / receivers is installed on the upstream side and the downstream side in the flow direction of one surface of a measurement tube body made of a square tube through which a measurement fluid flows. In addition, an ultrasonic reflector having a higher ultrasonic reflectivity than the inner surface of the surrounding tube is disposed on a surface of the tube facing the mounting surface of the ultrasonic transmitter / receiver, and the ultrasonic transmission / reception on the upstream side or the downstream side is arranged. An ultrasonic flowmeter in which an ultrasonic beam transmitted from a vessel is reflected by the ultrasonic reflector and propagates to the ultrasonic transmitter / receiver on the downstream side or the upstream side, and the surface roughness of the ultrasonic reflector is measured By changing along the direction orthogonal to the tube axis, the distribution of the ultrasonic reflectance of the ultrasonic reflector in the direction orthogonal to the tube axis of the tube is adjusted, and the amplitude distribution of the ultrasonic beam is It is characterized by equalization in the tube.
Furthermore, in the ultrasonic flowmeter according to the present invention, at least one pair of ultrasonic transmitters / receivers is installed on the upstream side and the downstream side in the flow direction of one surface of a measurement tube body including a square tube through which a measurement fluid flows. In addition, an ultrasonic reflector having a higher ultrasonic reflectivity than the inner surface of the surrounding tube is disposed on a surface of the tube facing the mounting surface of the ultrasonic transmitter / receiver, and the ultrasonic transmission / reception on the upstream side or the downstream side is arranged. An ultrasonic flowmeter in which an ultrasonic beam transmitted from a vessel is reflected by the ultrasonic reflector and propagates to the ultrasonic transmitter / receiver on the downstream side or the upstream side, and is inclined with respect to the mounting surface of the ultrasonic reflector Is changed along the direction orthogonal to the tube axis to adjust the distribution of the ultrasonic reflectance of the ultrasonic reflector in the direction orthogonal to the tube axis of the tube, and the amplitude distribution of the ultrasonic beam is It is characterized by equalization in the tube That.

本発明に係る超音波流量計によれば、少なくとも１対以上の超音波送受信器により送受信され、超音波反射体を経た超音波ビームは伝播路上の流速の平均値に応じた伝播時間差を与え、更に超音波反射体は送信振幅に拘わらず受信振幅を均一にして反射するので、得られる時間差信号は断面内の流速を平均したものとなる。 According to the ultrasonic flowmeter of the present invention, the ultrasonic beam transmitted / received by at least one pair of ultrasonic transmitter / receiver and passing through the ultrasonic reflector gives a propagation time difference according to the average value of the flow velocity on the propagation path, Furthermore, since the ultrasonic reflector reflects the reception amplitude evenly regardless of the transmission amplitude, the obtained time difference signal is obtained by averaging the flow velocity in the cross section.

本発明を図示の実施例に基づいて詳細に説明する。 The present invention will be described in detail based on the embodiments shown in the drawings.

図１は実施例１の超音波流量計の構成図である。管軸をｚ軸方向とし、測定流体を流す測定用管体１は、断面矩形状又は方形の角管とされ、管体１の上面１ａの上流側及び下流側には１対の超音波送受信器２、３が取り付けられている。なお、管軸のｚ軸方向と直交する水平方向をｘ軸、上下方向をｙ軸とする。 FIG. 1 is a configuration diagram of the ultrasonic flowmeter according to the first embodiment. The tube 1 for measurement in which the tube axis is the z-axis direction and the measurement fluid flows is a rectangular tube having a rectangular or rectangular cross section, and a pair of ultrasonic transmission / reception is provided upstream and downstream of the upper surface 1a of the tube 1. Containers 2 and 3 are attached. The horizontal direction orthogonal to the z-axis direction of the tube axis is the x-axis and the vertical direction is the y-axis.

超音波送受信器２、３間の管体１の下面１ｂの内面には、超音波反射率を大きくした超音波反射体４が配置されており、超音波反射体４の周囲の面は超音波反射率が十分に低くされている。そして、超音波送受信器２、３には、図示しない駆動測定回路を接続するリード線５、５’及び６、６’がそれぞれ接続されている。 On the inner surface of the lower surface 1b of the tube 1 between the ultrasonic transmitters / receivers 2 and 3, an ultrasonic reflector 4 having an increased ultrasonic reflectivity is disposed, and the surface around the ultrasonic reflector 4 is ultrasonic. The reflectivity is sufficiently low. The ultrasonic transceivers 2 and 3 are connected to lead wires 5, 5 ′ and 6, 6 ′ for connecting a drive measurement circuit (not shown).

このような構成により、上流側の超音波送受信器２内の任意の点Ａ及び点Ｂから送信される超音波ビームは、それぞれ超音波反射体４内の点Ａ’及び点Ｂ’で反射し、点Ａ”及び点Ｂ”において下流側の超音波送受信器３に達する。下流側の超音波送受信器３から上流側に超音波ビームが送られる場合には、上記の逆の経路を経て伝播する。 With such a configuration, ultrasonic beams transmitted from arbitrary points A and B in the upstream ultrasonic transceiver 2 are reflected at points A ′ and B ′ in the ultrasonic reflector 4, respectively. , The ultrasonic transmitter / receiver 3 on the downstream side is reached at the points A ″ and B ″. When an ultrasonic beam is sent from the downstream ultrasonic transmitter / receiver 3 to the upstream side, it propagates through the reverse path.

超音波ビームは時間差方式では一般にバースト波で駆動するが、或る特定時刻ｔの近傍における受信波形に着目すれば正弦波と見倣せるので、点Ａ及び点Ｂを通る超音波ビームの振幅をそれぞれＶａ及びＶｂとすれば、時間差方式の動作式から、次式（１）、（２）が得られる。ただし、流体中の超音波ビームの減衰は無視している。
Ｖａ＝ａ・ｍａ・ｓｉｎ{２πｆ(ｔ±ｖａ・ｓｉｎθ・Ｔ／２Ｃ)} …（１）
Ｖｂ＝ｂ・ｍｂ・ｓｉｎ{２πｆ(ｔ±ｖｂ・ｓｉｎθ・Ｔ／２Ｃ)} …（２） Although the ultrasonic beam is generally driven by a burst wave in the time difference method, it can be imitated as a sine wave if attention is paid to the received waveform in the vicinity of a specific time t. Therefore, the amplitude of the ultrasonic beam passing through the points A and B is changed. Assuming that Va and Vb respectively, the following equations (1) and (2) can be obtained from the time difference operation equation. However, the attenuation of the ultrasonic beam in the fluid is ignored.
Va = a · ma · sin {2πf (t ± va · sin θ · T / 2C)} (1)
Vb = b · mb · sin {2πf (t ± vb · sin θ · T / 2C)} (2)

ここで、ａ、ｂはそれぞれの超音波ビームの送信振幅の最大値、ｍａ、ｍｂはそれぞれ点Ａ’及び点Ｂ’における超音波反射体４の反射率、ｆは超音波送受信器２、３の駆動周波数、±の符号は下流向けが−、上流向けが＋に対応し、ｖａ、ｖｂはそれぞれ点Ａ’及び点Ｂ’を通る超音波ビームの伝播路上の流速の平均値、θは超音波ビームの入射角、Ｔは超音波ビームの伝播時問、Ｃは流体の音速である。 Here, a and b are the maximum transmission amplitude values of the respective ultrasonic beams, ma and mb are the reflectances of the ultrasonic reflector 4 at the points A ′ and B ′, respectively, and f is the ultrasonic transceivers 2 and 3. , The sign of ± corresponds to − for the downstream and + for the upstream, va and vb are the average values of the flow velocity of the ultrasonic beam passing through the points A ′ and B ′, respectively, and θ is super The incident angle of the acoustic beam, T is the propagation time of the ultrasonic beam, and C is the speed of sound of the fluid.

一般に、超音波ビームの送信振幅はｘ軸方向、つまり管体１の幅方向に一様に分布するものでなく、超音波送受信器２、３で超音波振動子として使用するピエゾ振動子の中央部は送信振幅が大きく、周辺部は小さくなる。従って、超音波反射体４のｘ軸方向の反射率分布が一様な場合には、受信側の超音波送受信器の受信振幅も一様にならない。 In general, the transmission amplitude of an ultrasonic beam is not uniformly distributed in the x-axis direction, that is, the width direction of the tube 1, and is the center of a piezoelectric vibrator used as an ultrasonic vibrator in the ultrasonic transceivers 2 and 3. The part has a large transmission amplitude and the peripheral part becomes small. Therefore, when the reflectance distribution in the x-axis direction of the ultrasonic reflector 4 is uniform, the reception amplitude of the ultrasonic transmitter / receiver on the receiving side is not uniform.

そこで、超音波反射体４のｘ軸方向の反射率分布を調整して、常にａ・ｍａ＝ｂ・ｍｂ≡ｐ（定数）が成立するように構成すると、受信振幅の最大値のｘ軸方向の分布は一様になる。即ち、超音波送受信器２、３は周波数が同一で、振幅がｘ軸方向に一様となり、受信側の超音波送受信器では超音波ビームの伝播路上の流速の平均値に依存する位相を有する波形を受信することになる。 Therefore, if the reflectance distribution in the x-axis direction of the ultrasonic reflector 4 is adjusted so that a · ma = b · mb≡p (constant) is always established, the maximum value of the reception amplitude in the x-axis direction The distribution of becomes uniform. That is, the ultrasonic transmitters / receivers 2 and 3 have the same frequency and the same amplitude in the x-axis direction, and the receiving ultrasonic transmitter / receiver has a phase that depends on the average value of the flow velocity on the propagation path of the ultrasonic beam. A waveform is received.

図２は超音波送受信器からの超音波ビームのｘ軸方向の送信振幅の分布を示し、通常では管体１の中央で最大振幅値ａ、ｂが大きくなる。図３は図２の送信振幅に対応して受信側の超音波送受信器で受信する振幅が一様となるように調整した超音波反射体４のｚ方向長さを示している。 FIG. 2 shows the distribution of the transmission amplitude of the ultrasonic beam from the ultrasonic transmitter / receiver in the x-axis direction. Usually, the maximum amplitude values a and b increase at the center of the tube 1. FIG. 3 shows the length in the z direction of the ultrasonic reflector 4 adjusted so that the amplitude received by the ultrasonic transmitter / receiver on the receiving side is uniform corresponding to the transmission amplitude of FIG.

このように、送信振幅に対し図１に示すように、超音波反射体４のｚ軸方向の長さを調整すると、受信側での超音波送受信器で受信した超音波ビームの分布が均等化される。 As described above, when the length of the ultrasonic reflector 4 in the z-axis direction is adjusted with respect to the transmission amplitude, the distribution of the ultrasonic beam received by the ultrasonic transmitter / receiver on the receiving side is equalized. Is done.

次式（３）の正弦和の公式を利用し、式（１）、（２）の２つの超音波ビームの平均振幅Ｖを計算すると、式（４）を得る。
ｓｉｎＥ＋ｓｉｎＦ＝２・ｓｉｎ(Ｅ＋Ｆ)／２・ｃｏｓ(Ｅ−Ｆ)／２ …（３）
Ｖ＝２・ｐ・ｓｉｎ[２πｆ{ｔ±(ｖａ＋ｖｂ)／２}・ｓｉｎθ・Ｔ／２Ｃ]・ｃｏｓ{２πｆ・(ｖａ−ｖｂ)ｓｉｎθ・Ｔ／２Ｃ} …（４） When the average amplitude V of the two ultrasonic beams of the formulas (1) and (2) is calculated using the sine sum formula of the following formula (3), the formula (4) is obtained.
sinE + sinF = 2 · sin (E + F) / 2 · cos (EF) / 2 (3)
V = 2 · p · sin [2πf {t ± (va + vb) / 2} · sin θ · T / 2C] · cos {2πf · (va−vb) sin θ · T / 2C} (4)

ここで、流体の音速Ｃに比べて流速が十分に小さいとすると、上式のｃｏｓ項は１と見倣せるので、これを省略すれば、平均振幅Ｖは２つの流速ｖａ、ｖｂの平均値（ｖａ＋ｖｂ）／２のときの時間差方式の動作式にほかならない。 Here, if the flow velocity is sufficiently smaller than the sound velocity C of the fluid, the cos term in the above equation can be regarded as 1, so if this is omitted, the average amplitude V is the average value of the two flow velocity va and vb. It is nothing but an operation formula of the time difference method when (va + vb) / 2.

上述の関係は任意の超音波ビームについて成立するので、結局は超音波送受信器２、３は超音波ビームの方向とｘ軸とにより定まる平面上の流速の平均値を検出することができる。 Since the above relationship holds for an arbitrary ultrasonic beam, the ultrasonic transceivers 2 and 3 can eventually detect the average value of the flow velocity on the plane determined by the direction of the ultrasonic beam and the x-axis.

図４は管体１の上面１ｂに実施例２の２対の超音波送受信器２、３、２’、３’を配置した例を示し、図５及び図６はこのときの超音波ビームの送信振幅分布及び超音波反射体４の長さの分布を示している。 FIG. 4 shows an example in which the two pairs of ultrasonic transmitters / receivers 2, 3, 2 ′, 3 ′ of Example 2 are arranged on the upper surface 1b of the tubular body 1, and FIGS. 5 and 6 show the ultrasonic beam at this time. The transmission amplitude distribution and the length distribution of the ultrasonic reflector 4 are shown.

複数対の超音波送受信器２、３、２’、３’の電気的接続については、上流側又は下流側ごとに、同じ極性の電極をリード線５、５’及びリード線６、６’により相互に接続されている。 For electrical connection of a plurality of pairs of ultrasonic transmitters / receivers 2, 3, 2 ′, 3 ′, electrodes having the same polarity are connected by lead wires 5, 5 ′ and lead wires 6, 6 ′ for each upstream side or downstream side. Are connected to each other.

この実施例２のように、使用する超音波送受信器２、３の対数を増加すれば、発信強度はより一様な分布に近付くが、一方で取り付けの煩雑さは増加する。 If the logarithm of the ultrasonic transceivers 2 and 3 to be used is increased as in the second embodiment, the transmission intensity approaches a more uniform distribution, but on the other hand, the mounting complexity increases.

なお、超音波反射体４の反射率を調整する手段として、図３、図６では超音波反射体４のｚ軸方向の長さを変化させたが、別の方法も考えられる。 As a means for adjusting the reflectance of the ultrasonic reflector 4, the length of the ultrasonic reflector 4 in the z-axis direction is changed in FIGS. 3 and 6, but other methods are also conceivable.

例えば、図７は実施例１のように、１対の超音波送受信器２、３を用いた場合の超音波反射体４の表面粗度のｘ軸方向分布を調整した例を示している。流体中の超音波ビームの波長に比べて小さくない大きさで、超音波反射体４の表面に凹凸を形成し超音波ビームを散乱させている。凹凸の密度の高い部分ほど散乱が多くなるので、図３に示すように超音波ビームの振幅に対応させて、中央部ほど散乱が大きくなるように凹凸密度の分布を変化させることで、超音波反射率を調整することができる。 For example, FIG. 7 shows an example in which the x-axis direction distribution of the surface roughness of the ultrasonic reflector 4 when the pair of ultrasonic transceivers 2 and 3 is used as in the first embodiment is shown. Concavities and convexities are formed on the surface of the ultrasonic reflector 4 to scatter the ultrasonic beam with a size not smaller than the wavelength of the ultrasonic beam in the fluid. Since the portion with higher unevenness density has more scattering, as shown in FIG. 3, the unevenness density distribution is changed so that the scattering becomes larger at the center portion corresponding to the amplitude of the ultrasonic beam. The reflectivity can be adjusted.

図８は他の超音波反射体４の例を示し、超音波反射体４の取付面に対する傾きを変化させてｘ軸方向分布を調整している。傾きが大きい部分ほど、受信側の超音波送受信器への超音波ビームの反射が少なくなるので、ｘ軸方向の中央部における傾きを大きくすることで、中央部の超音波反射率を小さくしている。 FIG. 8 shows another example of the ultrasonic reflector 4, and the x-axis direction distribution is adjusted by changing the inclination of the ultrasonic reflector 4 with respect to the mounting surface. As the inclination is larger, the reflection of the ultrasonic beam to the ultrasonic transmitter / receiver on the receiving side is reduced. Therefore, by increasing the inclination at the central portion in the x-axis direction, the ultrasonic reflectance at the central portion is reduced. Yes.

上述したように、本発明の超音波流量計は角管を使用しているが、通常の管路は円管であるので、測定部の前後に角管から成る測定用管体１を円形管に変形するレジューサ管７を図９に示すように接続し、管体１と両側の円管８の断面形状を整合させることが好ましい。 As described above, the ultrasonic flowmeter of the present invention uses a square tube, but since a normal pipe line is a circular tube, a measuring tube 1 made of a square tube is provided before and after the measurement unit as a circular tube. It is preferable to connect the reducer pipes 7 deformed to the shape shown in FIG. 9 so that the cross-sectional shapes of the pipe body 1 and the circular pipes 8 on both sides are matched.

実施例１の構成図である。1 is a configuration diagram of Example 1. FIG. 超音波ビームのｘ軸方向の発信振幅分布図である。It is a transmission amplitude distribution map of the x-axis direction of an ultrasonic beam. 超音波反射体のｘ軸方向の長さ分布図である。It is the length distribution figure of the x-axis direction of an ultrasonic reflector. 実施例２の構成図である。FIG. 6 is a configuration diagram of Example 2. 超音波ビームのｘ軸方向の発信振幅の分布図である。It is a distribution map of the transmission amplitude of the ultrasonic beam in the x-axis direction. 超音波反射体のｘ軸方向の長さ分布図である。It is the length distribution figure of the x-axis direction of an ultrasonic reflector. 表面に凹凸を設けて超音波反射率を変化させた超音波反射体の斜視図である。It is a perspective view of the ultrasonic reflector which provided unevenness | corrugation in the surface and changed the ultrasonic reflectivity. 表面の傾きを変えて超音波反射率を変化させた超音波反射体の斜視図である。It is the perspective view of the ultrasonic reflector which changed the inclination of the surface and changed the ultrasonic reflectivity. 管体の上流側及び下流側にレジューサ管を接続した状態の断面図である。It is sectional drawing of the state which connected the reducer pipe | tube to the upstream and downstream of a tubular body.

符号の説明Explanation of symbols

１測定用管体
２、３、２’、３’ 超音波送受信器
４超音波反射体
５、５’、６、６’ リード線
７レジューサ管 1 Measurement tube 2, 3, 2 ', 3' Ultrasonic transceiver 4 Ultrasonic reflector 5, 5 ', 6, 6' Lead wire 7 Reducer tube

Claims

測定流体を流す角管から成る測定用管体のｌつの面の流れ方向の上流側と下流側に、少なくとも１対の超音波送受信器を設置すると共に、前記管体内の前記超音波送受信器の取付面と対向する面上に周囲の管内面よりも超音波反射率が大きい超音波反射体を配置し、前記上流側又は下流側の超音波送受信器から発信した超音波ビームが前記超音波反射体で反射して前記下流側又は上流側の前記超音波送受信器に伝播する超音波流量計であって、前記超音波反射体の前記管体の管軸方向の長さを管軸に直交する方向に沿って変化させることにより、前記超音波反射体の前記管体の管軸と直交する方向の超音波反射率の分布を調整し、前記超音波ビームの振幅分布が前記管体内で均等化するようにしたことを特徴とする超音波流量計。 At least one pair of ultrasonic transmitters / receivers is installed on the upstream side and the downstream side in the flow direction of one surface of a measurement tube body made of a square tube through which a measurement fluid flows, and the ultrasonic transmitter / receiver in the tube body An ultrasonic reflector having a higher ultrasonic reflectivity than the inner surface of the surrounding tube is disposed on the surface facing the mounting surface, and the ultrasonic beam transmitted from the upstream or downstream ultrasonic transceiver is reflected by the ultrasonic reflection. An ultrasonic flowmeter that is reflected by a body and propagates to the downstream or upstream ultrasonic transmitter / receiver, wherein the length of the ultrasonic reflector in the tube axis direction of the tube is orthogonal to the tube axis By changing along the direction, the distribution of the ultrasonic reflectivity in the direction perpendicular to the tube axis of the tube of the ultrasonic reflector is adjusted, and the amplitude distribution of the ultrasonic beam is equalized in the tube An ultrasonic flow meter characterized in that it is designed to be used.

測定流体を流す角管から成る測定用管体のｌつの面の流れ方向の上流側と下流側に、少なくとも１対の超音波送受信器を設置すると共に、前記管体内の前記超音波送受信器の取付面と対向する面上に周囲の管内面よりも超音波反射率が大きい超音波反射体を配置し、前記上流側又は下流側の超音波送受信器から発信した超音波ビームが前記超音波反射体で反射して前記下流側又は上流側の前記超音波送受信器に伝播する超音波流量計であって、前記超音波反射体の表面粗度を管軸に直交する方向に沿って変化させることにより、前記超音波反射体の前記管体の管軸と直交する方向の超音波反射率の分布を調整し、前記超音波ビームの振幅分布が前記管体内で均等化するようにしたことを特徴とする超音波流量計。 At least one pair of ultrasonic transmitters / receivers is installed on the upstream side and the downstream side in the flow direction of one surface of a measurement tube body made of a square tube through which a measurement fluid flows, and the ultrasonic transmitter / receiver in the tube body An ultrasonic reflector having a higher ultrasonic reflectivity than the inner surface of the surrounding tube is disposed on the surface facing the mounting surface, and the ultrasonic beam transmitted from the upstream or downstream ultrasonic transceiver is reflected by the ultrasonic reflection. An ultrasonic flowmeter that reflects on a body and propagates to the downstream or upstream ultrasonic transmitter / receiver, and changes the surface roughness of the ultrasonic reflector along a direction perpendicular to the tube axis. By adjusting the distribution of the ultrasonic reflectance of the ultrasonic reflector in the direction perpendicular to the tube axis of the tubular body, the amplitude distribution of the ultrasonic beam is made uniform in the tubular body. Ultrasonic flow meter.

測定流体を流す角管から成る測定用管体のｌつの面の流れ方向の上流側と下流側に、少なくとも１対の超音波送受信器を設置すると共に、前記管体内の前記超音波送受信器の取付面と対向する面上に周囲の管内面よりも超音波反射率が大きい超音波反射体を配置し、前記上流側又は下流側の超音波送受信器から発信した超音波ビームが前記超音波反射体で反射して前記下流側又は上流側の前記超音波送受信器に伝播する超音波流量計であって、前記超音波反射体の取付面に対する傾きを管軸に直交する方向に沿って変化させることにより、前記超音波反射体の前記管体の管軸と直交する方向の超音波反射率の分布を調整し、前記超音波ビームの振幅分布が前記管体内で均等化するようにしたことを特徴とする超音波流量計。 At least one pair of ultrasonic transmitters / receivers is installed on the upstream side and the downstream side in the flow direction of one surface of a measurement tube body made of a square tube through which a measurement fluid flows, and the ultrasonic transmitter / receiver in the tube body An ultrasonic reflector having a higher ultrasonic reflectivity than the inner surface of the surrounding tube is disposed on the surface facing the mounting surface, and the ultrasonic beam transmitted from the upstream or downstream ultrasonic transceiver is reflected by the ultrasonic reflection. An ultrasonic flowmeter that reflects on a body and propagates to the downstream side or upstream side ultrasonic transmitter / receiver, and changes an inclination of the ultrasonic reflector with respect to a mounting surface along a direction orthogonal to a tube axis. By adjusting the distribution of ultrasonic reflectivity in the direction perpendicular to the tube axis of the tube of the ultrasonic reflector, the amplitude distribution of the ultrasonic beam is made uniform in the tube. The characteristic ultrasonic flowmeter.

複数対の前記超音波送受信器を用いる場合に、上流側又は下流側ごとに同じ極性の電極を相互に接続することを特徴とする請求項１〜３の何れか1つの請求項に記載の超音波流量計。 When using the ultrasonic transceiver pairs, according to any one of claims 1-3, characterized in that for connecting the upstream or downstream by the same polarity side electrode mutually super Sonic flow meter.

前記測定用管体の上流側及び下流側に、前記管体と外部接続配管との断面形状を整合するレジューサ管を接続することを特徴とする請求項１〜３の何れか1つの請求項に記載の超音波流量計。 The reducer pipe | tube which matches the cross-sectional shape of the said pipe body and external connection piping is connected to the upstream and downstream of the said measurement pipe body, The claim any one of Claims 1-3 characterized by the above-mentioned. The described ultrasonic flowmeter.