JP2793699B2 - Mass flow meter - Google Patents
Mass flow meterInfo
- Publication number
- JP2793699B2 JP2793699B2 JP16187590A JP16187590A JP2793699B2 JP 2793699 B2 JP2793699 B2 JP 2793699B2 JP 16187590 A JP16187590 A JP 16187590A JP 16187590 A JP16187590 A JP 16187590A JP 2793699 B2 JP2793699 B2 JP 2793699B2
- Authority
- JP
- Japan
- Prior art keywords
- sensor tube
- sensor
- fluid
- attenuation
- vibration
- 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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Links
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- Measuring Volume Flow (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は質量流量計に係り、特に流体の流れるセンサ
チューブを振動させ、流体の流量に応じて発生するコリ
オリカによるセンサチューブの変位を検出して流量を計
測する質量流量計に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mass flowmeter, and more particularly, to a mass flowmeter that vibrates a sensor tube through which a fluid flows, and detects a displacement of the sensor tube due to Corioliser generated according to the flow rate of the fluid. The present invention relates to a mass flow meter for measuring
従来の技術 被側流体の流量は流体の種類，物性（密度，粘度な
ど），プロセス条件（温度，圧力）によって影響を受け
ない質量で表されることが望ましい。2. Description of the Related Art It is desirable that the flow rate of a target fluid be represented by a mass that is not affected by the type of fluid, physical properties (density, viscosity, etc.), and process conditions (temperature, pressure).
そのため、被側流体の質量流量を計測する種々の質量
流量計が開発されつつあり、その中の一つとして振動す
るセンサチューブ内に流体を流したときに生ずるコリオ
リの力を利用して質量流量を直接計測する流量計があ
る。For this reason, various mass flow meters for measuring the mass flow rate of the fluid to be measured are being developed, and one of the mass flow meters is to utilize the Coriolis force generated when a fluid is caused to flow in a vibrating sensor tube. There is a flow meter that measures directly.
この種の質量流量計においては、一対のセンサチュー
ブに流体を流し、加振器（励磁コイル）の駆動力により
一対のセンサチューブを互いに近接，離間する方向に振
動させる構成とされている。コリオリの力はセンサチュ
ーブの振動方向に働き、かつ入口側と出口側とで逆向き
であるのでセンサチューブに捩れが生じ、この捩れ角は
質量流量に比例する。従って、一対のセンサチューブの
入口側及び出口側夫々の捩れる位置に振動を検出するピ
ックアップ（振動センサ）を設け、両センサの出力検出
信号の時間差を計測して上記センサチューブの捩れ、つ
まり質量流量を計測している。In this type of mass flow meter, a fluid is caused to flow through a pair of sensor tubes, and the pair of sensor tubes is vibrated in a direction to move toward and away from each other by a driving force of a vibrator (excitation coil). The Coriolis force acts in the direction of vibration of the sensor tube and is opposite between the inlet side and the outlet side, so that the sensor tube is twisted, and the twist angle is proportional to the mass flow rate. Accordingly, a pickup (vibration sensor) for detecting vibration is provided at each of the twisted positions on the inlet side and the outlet side of the pair of sensor tubes, and the time difference between the output detection signals of the two sensors is measured to determine the torsion of the sensor tube, that is, the mass. The flow rate is being measured.
一般の産業流体及び粘体の質量流量を計測するこのよ
うな質量流量計では、メンテナンス不可な計測部の異常
診断を行い流量計の信頼性を向上させていた。In such a mass flow meter that measures the mass flow rate of general industrial fluids and viscous bodies, the abnormality of the measurement unit that cannot be maintained is diagnosed to improve the reliability of the flow meter.
従来はこのような、異常診断を行なう場合、一対の平
行なチューブの振動信号のバランスを監視し、バランス
の平行状態が乱れた時に異常と判定し、警告を発する形
を取っていた。Conventionally, when such an abnormality diagnosis is performed, the balance between the vibration signals of a pair of parallel tubes is monitored, and when the parallel state of the balance is disturbed, an abnormality is determined and a warning is issued.
発明が解決しようとする課題 しかるに、従来の質量流量計は一対の平行なチューブ
の振動信号のバランスを監視し、バランスの平衡状態が
乱れた時に異常信号を発する形を取っていたため、一対
（２本）のチューブに均一な経年変化が生じている場合
の異常を知ることができず、例えば、チューブの振動に
よる疲労、又は腐食性流体による減少等の経年変化的異
常が感知できない等の問題点があった。Problems to be Solved by the Invention However, the conventional mass flow meter monitors the balance of the vibration signals of a pair of parallel tubes and generates an abnormal signal when the balance is out of balance. The problem is that it is not possible to know the abnormalities when the tubes of the present book have undergone uniform aging, and for example, it is not possible to detect aging abnormalities such as fatigue due to tube vibration or reduction due to corrosive fluid. was there.
本発明は上記の点に鑑みてなされたもので、経年変化
的異常も感知できる質量流量計を提供することを目的と
する。The present invention has been made in view of the above points, and an object of the present invention is to provide a mass flow meter capable of detecting aging abnormalities.
課題を解決するための手段 本発明は流体が流れるセンサチューブを励振手段によ
り振動させ、流体の流量に応じて発生するコリオリカに
よるセンサチューブの変位を検出手段により検出して流
量を計測する質量流量計において、前記センサチューブ
に流体を流さない状態で、前記センサチューブを一担振
動させた後に停止させるように前記励振手段を制御する
励振制御手段と、前記センサチューブの振動減衰を検出
する検出手段と、前記センサチューブの振動停止後の減
衰の仕方を前記検出手段により検出し、減衰の仕方に応
じて前記センサチューブの異常を判断する判断手段と、
前記判断手段が前記センサチューブに異常があると判断
したときに警報を発する警報手段とを具備してなる。Means for Solving the Problems The present invention vibrates a sensor tube through which a fluid flows by an excitation unit, and detects a displacement of the sensor tube due to Corioliser generated according to the flow rate of the fluid by a detection unit to measure a mass flow rate. In the state in which the fluid does not flow through the sensor tube, excitation control means for controlling the excitation means to stop after vibrating the sensor tube once, detection means for detecting the vibration attenuation of the sensor tube Determining means for detecting the attenuation of the sensor tube after the vibration of the sensor tube is stopped by the detection means, and determining abnormality of the sensor tube according to the attenuation method;
Alarm means for issuing an alarm when the judgment means judges that the sensor tube is abnormal.
作用 センサチューブの異常を流体の流れていない状態で励
振制御手段により励振手段を制御してセンサチューブを
一担振動させた後に停止させる。検出手段により停止後
のセンサチューブの振動の減衰を検出し、判断手段はこ
の減衰の仕方によりセンサチューブの異常を判断する。
警報手段は判断手段がセンサチューブに異常があると検
出すると警報を発し、センサチューブに異常があること
を知らせる。Function The abnormality of the sensor tube is stopped after the excitation means is controlled by the excitation control means in a state where the fluid is not flowing and the sensor tube is vibrated once. The detecting means detects the attenuation of the vibration of the sensor tube after the stop, and the judging means judges the abnormality of the sensor tube based on the manner of the attenuation.
The alarming means issues an alarm when the judging means detects that the sensor tube is abnormal, and notifies that the sensor tube is abnormal.
実施例 第１図は本発明の一実施例のブロック図を示す。Embodiment FIG. 1 shows a block diagram of an embodiment of the present invention.
センサユニット１は第２図に示すように一対のセンサ
チューブ2,3がマニホールド４に組付けられてなる。マ
ニホールド４は流入管５の流出管６との間に設けられ、
流入管５より流入した流体をセンサチューブ2,3に分岐
させると共にセンサチューブ2,3から流出する流体を流
出管６より流出させる。The sensor unit 1 has a pair of sensor tubes 2 and 3 assembled to a manifold 4 as shown in FIG. The manifold 4 is provided between the inflow pipe 5 and the outflow pipe 6,
The fluid flowing from the inflow pipe 5 is branched to the sensor tubes 2 and 3, and the fluid flowing out of the sensor tubes 2 and 3 is discharged from the outflow pipe 6.
センサチュー２は、配管方向に延在する直管部2aと、
直管部2aと平行に延在する直管部2bと、直管部2a,2bの
先端で折り返すように曲げられた曲部2c,3dと、この曲
部2cと2dとを接続するＵ字状の接続部（管路）2eとより
なる。The sensor tube 2 includes a straight pipe portion 2a extending in a pipe direction,
A straight pipe portion 2b extending parallel to the straight pipe portion 2a, bent portions 2c and 3d bent at the ends of the straight pipe portions 2a and 2b, and a U-shaped connection between the bent portions 2c and 2d. And a connection portion (pipe) 2e having a shape of a circle.
又、センサチューブ３は上記センサチューブ２と同一
形状に形成され、直管部3a,3bが流出管６及び直管部2a,
2bと平行となるようにセンサチューブ２と右，左対称に
配設されている。なお、センサチューブ2,3の接続部2e,
3e間は保持部材８により接続保持されている。The sensor tube 3 is formed in the same shape as the sensor tube 2, and the straight pipe portions 3a and 3b are formed by the outflow pipe 6 and the straight pipe portions 2a and 2a.
The sensor tube 2 is arranged right and left symmetrically so as to be parallel to 2b. In addition, the connection part 2e of the sensor tubes 2, 3
The space between 3e is connected and held by the holding member 8.
保持部材８は流出管６が貫通するリング部8aの外周に
センサチューブ2,3の接続部2e,3eの中間位置に接続固定
される接続部8b,8cを有してなる。即ち、保持部材８は
流出管６を間に介して対向する接続部2e,3eを相互に保
持している。The holding member 8 has connecting portions 8b and 8c connected and fixed at an intermediate position between the connecting portions 2e and 3e of the sensor tubes 2 and 3 on the outer periphery of the ring portion 8a through which the outflow pipe 6 passes. That is, the holding member 8 mutually holds the connection portions 2e and 3e facing each other with the outflow pipe 6 interposed therebetween.
尚、リング部8aの内径は流出管６の外径よりも大径で
あり、流出量６の外周とリング部8aの内周との間には隙
間が介在している。従って、一対のセンサチューブ2,3
の接続部2e,3eは流出管６と非接触状態で所定の位置に
保持されており、流出管６からの配管振動はセンサチュ
ーブ2,3に直接伝達されないようになっている。Note that the inner diameter of the ring portion 8a is larger than the outer diameter of the outflow pipe 6, and a gap is interposed between the outer circumference of the outflow amount 6 and the inner circumference of the ring portion 8a. Therefore, a pair of sensor tubes 2 and 3
Are held at predetermined positions in a non-contact state with the outflow pipe 6, so that the piping vibration from the outflow pipe 6 is not directly transmitted to the sensor tubes 2, 3.
また、センサチューブ2,3は保持部材８の接続固定に
より流出管６を基準にして接続部2e,3eの離間位置がバ
ラツキなく所定の位置に位置決めされる。このように、
保持部材８によりセンサチューブ2,3の先端の接続部2e,
3eが離間しているにも拘らず設計された所定位置に保持
されることになり、接続部2e,3eに連続する直管部2a,2b
及び3a,3bの離間位置が所定位置に位置決めされるとと
もに各直管部2a,2b,3a,3bの平行度が保たれる。従っ
て、センサチューブ2,3を製作する際各直管部2a,2b,3a,
3bの延在位置又は平行度が若干ずれてしまったとして
も、上記保持部材８が接続部2e,3e間を接続保持するこ
とにより上記直管部2a,2b,3a,3bの組付加工誤差を無く
すように直管部2a,2b,3a,3bの組付位置を補正すること
ができる。Further, the sensor tubes 2 and 3 are fixedly connected to the holding member 8 so that the separated positions of the connecting portions 2e and 3e are positioned at predetermined positions with no variation with respect to the outflow pipe 6. in this way,
By the holding member 8, the connection portions 2e,
Despite the separation of 3e, it is held at the designed predetermined position, and the straight pipe sections 2a, 2b connected to the connection sections 2e, 3e.
3a, 3b is positioned at a predetermined position, and the straightness of each straight pipe portion 2a, 2b, 3a, 3b is maintained. Therefore, when manufacturing the sensor tubes 2 and 3, each straight pipe portion 2a, 2b, 3a,
Even if the extending position or parallelism of 3b is slightly shifted, the holding member 8 connects and holds the connecting portions 2e and 3e, so that the assembling processing error of the straight pipe portions 2a, 2b, 3a and 3b is increased. Can be corrected so that the straight pipe portions 2a, 2b, 3a, 3b are eliminated.
従って、保持部材８はセンサチューブ2,3を組付ける
際接続部2e,3e間を保持するとともに、各直管部2a,2b,3
a,3bの延在位置及び平行度を位置決めするための組付用
ゲージとしても機能しうる。Accordingly, the holding member 8 holds the space between the connecting portions 2e, 3e when assembling the sensor tubes 2, 3, and at the same time, holds the straight pipe portions 2a, 2b, 3
It can also function as an assembling gauge for positioning the extended positions of a and 3b and the degree of parallelism.
即ち、センサチューブ2,3が正しい位置に組付けられ
るので、後述するピックアップ9,10のコイル部とマグネ
ット部との位置関係を正確に規制することが可能とな
る。よって、組立完了後ピックアップ9,10のコイル部と
マグネット部との相対位置を調整する手間が不要とな
る。That is, since the sensor tubes 2 and 3 are assembled at correct positions, it is possible to accurately regulate the positional relationship between the coil portions and the magnet portions of the pickups 9 and 10 described below. Therefore, it is not necessary to adjust the relative positions of the coil portions and the magnet portions of the pickups 9 and 10 after the assembly is completed.
一対のセンサチューブ2,3の直管部2a,2b,3a,3bは支持
板７を貫通し、支持板７に溶接で固定されるとともに、
その端部はマニホールド４に接続固定されている。The straight pipe portions 2a, 2b, 3a, 3b of the pair of sensor tubes 2, 3 penetrate the support plate 7 and are fixed to the support plate 7 by welding.
Its end is connected and fixed to the manifold 4.
従って、一方のセンサチューブ２は流出管６の上方で
配管方向に延在して設けられ、他方のセンサチューブ３
は流出管６の下方で配管方向に延在して設けられている
ので、質量流量計１は一対のセンサチューブを2,3を有
するにもかかわらず設置スペースが小さくて済み、コン
パクトな構成となっている。Therefore, one sensor tube 2 is provided to extend in the pipe direction above the outflow pipe 6, and the other sensor tube 3 is provided.
Is provided extending in the pipe direction below the outflow pipe 6, so that the mass flow meter 1 has a small installation space despite having a pair of sensor tubes 2 and 3, and has a compact configuration. Has become.
流入側の直管部2aと3aとの間、及び流出側の直管部2b
と3bとの間にはピックアップ9,10が配設されている。従
って、センサチューブ2,3が振動すると、直管部2a,2bに
設けられたコイル部10a及び9aがマグネット10b,10c及び
9b,9c間で矢印Ｘ方向に相対的に変位する。このため、
コイル部9aには直管部2a,2b及び3a,3bの相対変位に応じ
た起電力が発生し、センサチューブの変位を検出する。Between the straight pipe sections 2a and 3a on the inflow side and the straight pipe section 2b on the outflow side
Pickups 9 and 10 are arranged between and 3b. Therefore, when the sensor tubes 2 and 3 vibrate, the coil portions 10a and 9a provided in the straight pipe portions 2a and 2b cause the magnets 10b and 10c and
It is relatively displaced in the arrow X direction between 9b and 9c. For this reason,
An electromotive force is generated in the coil section 9a in accordance with the relative displacement of the straight pipe sections 2a, 2b and 3a, 3b, and detects the displacement of the sensor tube.
13,14は加振器で、直管部2aと2bとの先端間，直管部3
aと3bとの先端間に設けられている。Reference numerals 13 and 14 denote vibrators between the ends of the straight pipe sections 2a and 2b and the straight pipe section 3
It is provided between the tips of a and 3b.
加振器13は実質電磁ソレノイドと同様な構成であり、
第４図に示すように流入側の直管部2aに取付けられたコ
イル部13aと、流出側の直管部2bに取付けられ、コイル
部13a内に嵌入するマグネット部13bとよりなる。従っ
て、加振器13はコイル部13aに通電されると、直管部2a,
2bを矢印Ｘ方向に加振する。The vibrator 13 has substantially the same configuration as the electromagnetic solenoid,
As shown in FIG. 4, a coil part 13a is attached to the inflow side straight pipe part 2a, and a magnet part 13b is attached to the outflow side straight pipe part 2b and fits in the coil part 13a. Therefore, when the vibrator 13 is energized to the coil portion 13a, the straight tube portion 2a,
2b is vibrated in the arrow X direction.
尚、加振器14は上記加振器13と同一構成であるので、
その説明は省略する。Since the vibrator 14 has the same configuration as the vibrator 13,
The description is omitted.
次に計測部11について第１図にもどって説明する。計
測部11はマイクロコンピュータ等により構成されてい
る。ピックアップ9,10は流量計測を行なう計測手段15に
接続されると共にセンサチューブ2,3の減衰を検出する
検出手段20bに接続される。計測手段15はピックアップ
9,10からの信号の位相差を検出して、その位相差よりセ
ンサチューブ2,3に流れる流体の質量流量を計測する。
計測手段15による計測結果は表示手段16に供給される。Next, the measuring section 11 will be described with reference to FIG. The measurement unit 11 is configured by a microcomputer or the like. The pickups 9 and 10 are connected to a measuring means 15 for measuring a flow rate and to a detecting means 20b for detecting attenuation of the sensor tubes 2 and 3. The measuring means 15 is a pickup
The phase difference between the signals from the sensors 9 and 10 is detected, and the mass flow rate of the fluid flowing through the sensor tubes 2 and 3 is measured from the phase difference.
The measurement result by the measuring means 15 is supplied to the display means 16.
計測手段15には表示手段16と共に、流体停止確認手段
17が接続される。流体停止確認手段17はセンサチューブ
2,3に流れる流体を停止させた状態で加振器13,14により
センサチューブ2,3を振動させたときのセンサチューブ
2,3の変位をピックアップ9,10により検出し、ピックア
ップ9,10の検出信号の位相差が零であれば流体が停止し
ていると判断し、励振制御手段18に停止信号を供給す
る。The measurement means 15 together with the display means 16 and the fluid stop confirmation means
17 is connected. Fluid stop confirmation means 17 is a sensor tube
Sensor tubes when sensor tubes 2 and 3 are vibrated by vibrators 13 and 14 with the fluid flowing through 2 and 3 stopped
The pickups 9 and 10 detect displacements of the pickups 9 and 10, and if the phase difference between the detection signals of the pickups 9 and 10 is zero, it is determined that the fluid is stopped, and a stop signal is supplied to the excitation control means 18.
励振制御手段18には故障検出動作を指示するための操
作スイッチ19が接続されると共に流体停確認手段17の出
力信号が入力される。励振制御手段18は流体停止確認手
段17から停止信号が供給され、かつ、操作スイッチ19が
オンされると、駆動回路20aを介して励振手段である加
振器13,14の駆動を停止して、センサチューブ2,3の振動
を停止させる。An operation switch 19 for instructing a failure detection operation is connected to the excitation control means 18 and an output signal of the fluid stop confirmation means 17 is input. When the stop signal is supplied from the fluid stop confirmation unit 17 and the operation switch 19 is turned on, the excitation control unit 18 stops driving the vibrators 13 and 14 as excitation units via the drive circuit 20a. Then, the vibration of the sensor tubes 2 and 3 is stopped.
加振器13,14は駆動回路20a0と接続される。 The vibrators 13 and 14 are connected to the drive circuit 20a0.
検出手段20bはピックアップ9,10出力信号よりセンサ
チューブ2,3の変位の減衰を検出してその検出信号判断
手段21に供給する。判断手段21にはタイマ22が接続され
ると共に検出手段20及び励振制御手段18より信号が入力
される。判断手段21は加振器13,14によるセンサチュー
ブ2,3の励振が停止し励振制御手段18より停止信号が入
力されてからの時間をタイマ22からのクロック信号によ
り計測して一定時間経過後の振動レベルを予め記憶させ
ておいた基準レベルと比較して振動レベルが基準レベル
に近似していればセンサチューブ2,3に異常がないと判
断し、振動レベルが基準レベルより大きくずれていると
きにはセンサチューブ2,3に異常があると判断する。The detection means 20b detects the attenuation of the displacement of the sensor tubes 2 and 3 from the output signals of the pickups 9 and 10 and supplies the detected signal to the detection signal determination means 21. A timer 22 is connected to the judging means 21, and signals are inputted from the detecting means 20 and the excitation control means 18. The judgment means 21 measures the time from when the excitation of the sensor tubes 2 and 3 by the vibrators 13 and 14 is stopped and the stop signal is input from the excitation control means 18 by the clock signal from the timer 22, and after a predetermined time elapses. If the vibration level is compared to the reference level stored in advance and the vibration level is close to the reference level, it is determined that there is no abnormality in the sensor tubes 2 and 3, and the vibration level is greatly deviated from the reference level. Sometimes, it is determined that the sensor tubes 2 and 3 are abnormal.
判断手段21は警報手段23に接続されていて、センサチ
ューブ2,3に異常があると判断すると警報手段23を動作
させ、センサチューブ2,3に異常があることを知らせ
る。The judging means 21 is connected to the alarm means 23 and, when judging that the sensor tubes 2 and 3 have an abnormality, operates the alarm means 23 to notify that the sensor tubes 2 and 3 have an abnormality.
ここで減衰状態の比較方法を第３図に示す。第３図
（Ａ）は正常な初期状態における励振停止直後の減衰を
示す。第３図（Ｂ）の場合は、減衰率が非常に大きくな
っている状態で、例えばセンサチューブ2,3への異物付
着の状態等異常を示す。また第３図（Ｃ）は減衰率が小
さくなっており、例えば腐食性流体などによる経年変化
的減肉などが発生した場合等が考えられる。FIG. 3 shows a method of comparing the attenuation state. FIG. 3A shows the attenuation immediately after the excitation is stopped in a normal initial state. In the case of FIG. 3 (B), when the attenuation rate is extremely large, an abnormality such as a state of foreign matter adhered to the sensor tubes 2 and 3 is shown. FIG. 3 (C) shows that the damping rate is small, and it is conceivable that, for example, aging thinning due to a corrosive fluid or the like occurs.
正常・異常を比較する方法として、第３図に示すよう
に流体が流れていない状態での励振停止から時間t0経過
の後の時間t1の範囲におけるセンサ出力電圧値で比較す
る。As a method of comparing the normal or abnormal, comparing the sensor output voltage value at the time range t 1 after the time t 0 has elapsed from the excitation stopped in a state where no fluid flows as shown in Figure 3.
次に点検時の動作について説明する。 Next, the operation at the time of inspection will be described.
点検はセンサチューブ2,3に流体を流さない状態で行
なう。このため、操作スイッチ19をオンしたときに、流
体停止手段17より流体の停止を確認する停止信号が励振
制御手段18に入力されていなければ加振器13,14が停止
されず以上判定動作は行なわれない構成とされている。The inspection is performed with no fluid flowing through the sensor tubes 2 and 3. For this reason, when the operation switch 19 is turned on, the exciters 13 and 14 are not stopped unless the stop signal for confirming the stop of the fluid is input to the excitation control unit 18 from the fluid stop unit 17 and the determination operation is not performed. The configuration is not performed.
まず、電源が投入とされ、加振器13,14により、セン
サチューブ2,3が振動し、かつ励振制御手段18に流体の
停止を示す停止信号が入力された状態で操作スイッチ19
をオンにすると励振制御手段18はセンサチューブ2,3を
停止させるように制御信号を駆動回路20aを介して加振
器13,14に供給する。このため、センサチューブ2,3は振
動状態より停止して振動が徐々に減衰する。First, when the power is turned on, the sensor tubes 2 and 3 are vibrated by the vibrators 13 and 14, and the stop signal indicating the stop of the fluid is input to the excitation control means 18, the operation switch 19 is turned on.
Is turned on, the excitation control means 18 supplies a control signal to the vibrators 13 and 14 via the drive circuit 20a so as to stop the sensor tubes 2 and 3. For this reason, the sensor tubes 2 and 3 stop from the vibration state, and the vibration gradually attenuates.
検出手段20bはピックアップ9,10の出力信号によりセ
ンサチューブ2,3の振動減衰を検出する。センサチュー
ブ2,3の振動減衰信号は判断手段21に供給される。The detection means 20b detects the vibration attenuation of the sensor tubes 2, 3 based on the output signals of the pickups 9, 10. The vibration damping signal of the sensor tubes 2 and 3 is supplied to the judgment means 21.
判断手段21はタイマ22からのクロックを利用して、加
振器13,14の停止後より時間を計測していて、一定時間t
0後の時間t1の振動レベル（振幅）を基準レベル（基準
振幅）と比較して、その期間での振動レベル基準レベル
と一致又はある一定の誤差内にあれば正常と判断し、あ
る一定の誤差以上となれば異常と判断する。The judging means 21 uses the clock from the timer 22 to measure the time after the exciters 13 and 14 are stopped, and
0 after a time t 1 of the vibration level (amplitude) is compared with a reference level (reference amplitude), it is determined to be normal if the vibration level reference level match or within a certain error in the time period, a certain If the error is equal to or larger than the error of, it is determined to be abnormal.
判断手段21が異常ありと判断すると警報手段23に警報
信号を供給する。警報手段23は判断手段21からの警報信
号を受けて異常を知らせる警報を発する。When the judging means 21 judges that there is an abnormality, an alarm signal is supplied to the alarm means 23. The alarming means 23 receives an alarm signal from the judging means 21 and issues an alarm to notify an abnormality.
このように本実施例では正常時の減衰を記憶させてお
き、これとの違いにより異常を検出しているため、経年
変化的な異常をも検出することができ、計測器としての
信頼性を向上させることができる。As described above, in the present embodiment, the normal attenuation is stored, and an abnormality is detected based on a difference from the normal attenuation. Therefore, an aging abnormality can be detected, and the reliability as a measuring instrument can be improved. Can be improved.
なお、本実施例では減衰の仕方を一定時間経過後の振
動流レベルを見ることにより判断したが、これに限るこ
とはなく、振動停止までの時間を比較することによって
も判断できる。例えば、第３図において、正常時の振動
停止時間をt2として記憶しておき、時間t3,t4を計測し
て時間t2と大きく異なるものは異常ありと判断する構成
のものも考えられる。In the present embodiment, the manner of damping is determined by looking at the vibration flow level after a certain period of time. However, the present invention is not limited to this, and can be determined by comparing the time until the vibration stops. For example, contemplated in Figure 3, stores the vibration downtime during normal as t 2, the time t 3, t 4 the measurement to the time t 2 and significantly different from others of the structure to determine that a malfunction occurs Can be
また、本実施例ではセンサチューブ2,3の減衰をピッ
クアップ9,10により検出しているが、減衰の検出時は加
振器13,14は駆動されないため、加振器13,14を利用して
検出を行なうこともできる。さらに、本実施例では電源
スイッチと異常検出のための操作スイッチ19とを別々の
構成としたが、電源スイッチと操作スイッチとを共通に
して、電源スイッチ投入時に同時に異常検出が行なわれ
る構成とすることもできる。Further, in the present embodiment, the attenuation of the sensor tubes 2 and 3 is detected by the pickups 9 and 10, but when the attenuation is detected, the vibrators 13 and 14 are not driven. Detection can also be performed. Further, in the present embodiment, the power switch and the operation switch 19 for detecting an abnormality are configured separately, but the power switch and the operation switch are commonly used, and the abnormality is detected simultaneously when the power switch is turned on. You can also.
なお、本実施例では流体停止確認手段17にはピックア
ップ9,10より直接信号が入力されているが、計測手段15
の計測結果を入力し、計測結果より流体の停止を確認す
る構成としてもよい。In the present embodiment, a signal is directly input from the pickups 9 and 10 to the fluid stop confirmation unit 17, but the measurement unit 15
The measurement result may be input and the stop of the fluid may be confirmed from the measurement result.
発明の効果 上述の如く、本発明によればセンサチューブの振動を
停止させた後の減衰の仕方によりセンサチューブの異常
を判断しているため、センサチューブに経年変化的劣化
が生じた場合でもその劣化による異常を検出することが
でき、製品の信頼性を向上させることができる等の特長
を有する。Effect of the Invention As described above, according to the present invention, the abnormality of the sensor tube is determined based on the manner of attenuation after stopping the vibration of the sensor tube. It has features such as being able to detect abnormalities due to deterioration and improving product reliability.
第１図は本発明の一実施例のブロック図、第２図はセン
サユニットの斜視図、第３図は異常の判断方法を説明す
るための図、第４図は本発明の一実施例の要部の断面図
である。 １……質量流量計、2,3……センサチューブ、9,10……
ピックアップ、13,14……加振器、18……励振制御手
段、20b……検出手段、21……判断手段、23……警報手
段。1 is a block diagram of one embodiment of the present invention, FIG. 2 is a perspective view of a sensor unit, FIG. 3 is a diagram for explaining a method of judging an abnormality, and FIG. 4 is a diagram of one embodiment of the present invention. It is sectional drawing of a principal part. 1 ... Mass flow meter, 2,3 ... Sensor tube, 9,10 ...
Pickup, 13, 14 ... Exciter, 18 ... Excitation control means, 20b ... Detection means, 21 ... Decision means, 23 ... Alarm means.
Claims (1)
より振動させ、該流体の流量に応じて発生するコリオリ
カによるセンサチューブの変位を検出して流量を計測す
る質量流量計において、 前記センサチューブに流体を流さない状態で、前記セン
サチューブを一担振動させた後、停止させるように前記
励振手段を制御する励振制御手段と、 前記センサチューブの振動減衰を検出する検出手段と、 前記センサチューブの振動停止後の減衰の仕方を前記検
出手段により検出し、該減衰の仕方を予め記憶された基
準となる減衰の仕方と比較して該比較結果に応じて前記
センサチューブの異常を判断する判断手段と、 前記判断手段が前記センサチューブに異常があると判断
したときに警報を発する警報手段とを具備したことを特
徴とする質量流量計。1. A mass flowmeter for measuring a flow rate by vibrating a sensor tube through which a fluid flows by an excitation means and detecting a displacement of the sensor tube due to Coriolisa generated according to the flow rate of the fluid, wherein the fluid is supplied to the sensor tube. Excitation control means for controlling the excitation means so as to stop after the sensor tube is caused to vibrate in a state where no air is caused to flow, detection means for detecting vibration attenuation of the sensor tube, and vibration of the sensor tube. Determining means for detecting a manner of attenuation after stopping by the detecting means, comparing the manner of attenuation with a previously stored reference manner of attenuation, and determining abnormality of the sensor tube according to the comparison result; And a warning means for issuing a warning when the determination means determines that the sensor tube is abnormal. Total.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16187590A JP2793699B2 (en) | 1990-06-20 | 1990-06-20 | Mass flow meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16187590A JP2793699B2 (en) | 1990-06-20 | 1990-06-20 | Mass flow meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0452516A JPH0452516A (en) | 1992-02-20 |
| JP2793699B2 true JP2793699B2 (en) | 1998-09-03 |
Family
ID=15743640
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16187590A Expired - Fee Related JP2793699B2 (en) | 1990-06-20 | 1990-06-20 | Mass flow meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2793699B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019135474A (en) * | 2018-02-05 | 2019-08-15 | 横河電機株式会社 | Coriolis flowmeter, period prediction system, and period prediction method |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU2004321718B2 (en) * | 2004-06-22 | 2009-11-05 | Micro Motion, Inc. | Meter electronics and method for detecting a residual material in a flow meter assembly |
| DE102005044008B4 (en) * | 2005-09-14 | 2007-07-12 | Krohne Ag | Method for testing a mass flowmeter |
| CA2622976C (en) * | 2005-09-19 | 2013-05-07 | Micro Motion, Inc. | Meter electronics and methods for verification diagnostics for a flow meter |
| JP4911219B2 (en) | 2009-11-10 | 2012-04-04 | 横河電機株式会社 | Coriolis mass flow meter |
| JP4952820B2 (en) * | 2010-05-13 | 2012-06-13 | 横河電機株式会社 | Coriolis flow meter |
-
1990
- 1990-06-20 JP JP16187590A patent/JP2793699B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019135474A (en) * | 2018-02-05 | 2019-08-15 | 横河電機株式会社 | Coriolis flowmeter, period prediction system, and period prediction method |
| JP7024466B2 (en) | 2018-02-05 | 2022-02-24 | 横河電機株式会社 | Coriolis flowmeter, time prediction system, and time prediction method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0452516A (en) | 1992-02-20 |
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