JPH0421128B2 - - Google Patents
Info
- Publication number
- JPH0421128B2 JPH0421128B2 JP10811081A JP10811081A JPH0421128B2 JP H0421128 B2 JPH0421128 B2 JP H0421128B2 JP 10811081 A JP10811081 A JP 10811081A JP 10811081 A JP10811081 A JP 10811081A JP H0421128 B2 JPH0421128 B2 JP H0421128B2
- Authority
- JP
- Japan
- Prior art keywords
- electromagnetic flowmeter
- correction
- signal
- flow
- flow rate
- 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
Links
- 238000012937 correction Methods 0.000 claims description 26
- 239000007788 liquid Substances 0.000 claims description 19
- 239000012530 fluid Substances 0.000 claims description 17
- 230000005284 excitation Effects 0.000 description 9
- 238000005259 measurement Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 230000005674 electromagnetic induction Effects 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000005279 excitation period Effects 0.000 description 1
- 239000012847 fine chemical Substances 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/56—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using electric or magnetic effects
- G01F1/58—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using electric or magnetic effects by electromagnetic flowmeters
- G01F1/60—Circuits therefor
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Details Of Flowmeters (AREA)
- Measuring Volume Flow (AREA)
Description
【発明の詳細な説明】
本発明は、測定条件、特に測定流体の種類によ
り発生するスパン変動を補正するように改良した
電磁流量計に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic flowmeter improved to correct span fluctuations caused by measurement conditions, particularly the type of fluid to be measured.
一般に、円管内の中心対称流はレイノルズ数
Reが2300付近を境とし、Re＜2300では層流（放
物線流速分布）、Re＞2300では乱流（指数関数流
速分布）となることが良く知られている。また、
均一な磁界をもつ電磁流量計では、層流と乱流い
ずれに対してもその平均流速（平均流量）に比例
した出力を発信することが知られている。 Generally, centrosymmetric flow in a circular pipe has a Reynolds number of
It is well known that Re reaches a boundary around 2300, and that when Re < 2300, the flow becomes laminar (parabolic flow velocity distribution), and when Re > 2300, the flow becomes turbulent (exponential flow velocity distribution). Also,
It is known that an electromagnetic flowmeter with a uniform magnetic field emits an output proportional to the average flow velocity (average flow rate) for both laminar flow and turbulent flow.
しかし近年では、センサ類の小形化、コストダ
ウンの目的により電磁流量計発信器の面間寸法
（測定用管路の長さに略々等しい）が縮小の傾向
にあり、それに伴つて不均一磁界が採用されてい
る。そのため、層流と乱流の区別なくその平均流
量を指示するということは、必らずしも当てはま
らなくなつている。つまり、通常、電磁流量計自
身の検定は水によりその乱流領域で行われるので
あるが、
(1) 乱流領域では流速分布がほぼ一様であるか
ら、乱流領域内の流体を対象とする測定には問
題ないが、
(2) フアイン・ケミカルや水処理プロセスの薬注
関係では、比較的粘度の高い流体を低流速度で
流すため、層流領域で使用することとなる。一
方、発信器自体の検定は水を使つて乱流域で行
うため、実使用状態での測定流体の条件によつ
ては発信器出力のスパン誤差が出やすいという
問題がある。特に、微小口径（例えば６〜
2.5Aの発信器）ではこのようなスパン誤差が
比較的起きやすいが、その原因は明確でないの
で、その原因を追及した結果、微小口径の電磁
流量計では円筒状の導管の側面に円柱状の電極
を導管の軸に直角に挿入する構成なので、これ
等の接合部に段差が生じ、この段差に起因して
スパン誤差が生じることが分かつた。しかし、
微小口径の電磁流量計ではこの段差をなくすこ
とは困難である。 However, in recent years, the face-to-face dimension of electromagnetic flowmeter transmitters (approximately equal to the length of the measurement pipe) has tended to shrink due to the miniaturization of sensors and cost reduction, and as a result, non-uniform magnetic fields has been adopted. Therefore, it is no longer always true to indicate the average flow rate without distinguishing between laminar flow and turbulent flow. In other words, normally the electromagnetic flowmeter itself is verified in its turbulent flow region using water, but (1) the flow velocity distribution is almost uniform in the turbulent flow region, so (2) For fine chemicals and chemical injection in water treatment processes, relatively high viscosity fluids flow at low flow speeds, so they must be used in the laminar flow region. On the other hand, since the transmitter itself is verified using water in a turbulent region, there is a problem in that span errors in the transmitter output are likely to occur depending on the conditions of the measured fluid in actual use. In particular, micro diameter (e.g. 6~
Such span errors are relatively easy to occur in the case of a 2.5A transmitter), but the cause is not clear, and as a result of investigating the cause, we found that in micro-diameter electromagnetic flowmeters, there is a cylindrical shape on the side of the cylindrical conduit. Since the electrodes are inserted perpendicularly to the axis of the conduit, a step is created at these joints, and it has been found that this step causes a span error. but,
It is difficult to eliminate this level difference with a micro-diameter electromagnetic flowmeter.
このような問題に対する現状での対応は必らず
しも十分ではなく、測定流体の種類に応じて測定
の都度、実液検定によるスパン補正が行われてき
たのであるが、この実液検定だとバツチで異種の
流体を流すときには流体の種類が異なることによ
るスパン誤差の補正に対応しきれない困難が生じ
ている。 Current solutions to such problems are not necessarily sufficient, and span corrections have been performed each time a measurement is made depending on the type of fluid to be measured. When different types of fluids are flowed in batches, it is difficult to compensate for span errors due to different types of fluids.
そこで、測定液体の粘度、密度など流体の物性
に関する情報を入力してこれを用いてレイノルズ
数Reを演算し、このレイノルズ数Reを用いて対
応する補正係数を演算し、発信器からの流量比例
信号をこの補正係数で補正する信号処理を行つて
その結果を出力する構成をとることが考えられ
る。 Therefore, input information on the physical properties of the fluid such as the viscosity and density of the liquid to be measured, use this to calculate the Reynolds number Re, use this Reynolds number Re to calculate the corresponding correction coefficient, and calculate the proportional flow rate from the transmitter. It is conceivable to adopt a configuration in which signal processing is performed to correct the signal using this correction coefficient and the result is output.
以下、図面に基づいてこの場合について説明す
る。第１図はこの種の電磁流量計の回路構成を示
す。この電磁流量計は、信号処理にマイクロコン
ピユータを使用した定電流駆動式の低周波励振形
電磁流量計である。予め、電磁流量計としての基
本構成及び動作を簡単に説明すると、１，２及び
３はそれぞれ励磁コイル、測定用管路及び一対の
電極であり、これらが電磁流量計発信器を構成す
る。４，５及び６はそれぞれバツフア増幅器、前
置増幅器及び演算制御回路であり、これらが電磁
流量計変換器を構成し、この例では演算制御回路
６がマイクロプロセツサ（以下、CPUと略称す
る）６ａ、メモリ６ｂ、マルチプレクサ（以下、
MPXと略称する）６ｃ、アナログ・デジタル変
換器（以下、ADCと略称する）６ｄ、デジタ
ル・アナログ変換器（以下、DACと略称する）
６ｅ及び入出力ポート（以下、Ｉ／Ｏと略称す
る）６ｆにより構成されている。なお、６ｇはデ
ータ・バス、６ｈはアドレス・バス、６ｉはコン
トロール・バス、６ｊと６ｋはそれぞれタイミン
グ信号である。励振回路７はこの例では商用周波
ノイズを除去するため、商用電源８に同期したタ
イミング信号６ｊにより制御されて商用周波数の
１／２、1/4、1/8等の周波数の励磁電流を作る。励
磁電流波形は正・負、正・ゼロ、負・ゼロ、正・
ゼロ、負・ゼロの極性のものや、あるいは正弦
波、三角波、台形波など各種のものが採用される
が、ここでは第２図ａの如き正・ゼロ・負・ゼロ
を繰返す矩形波とする。この励磁電流に対し電極
間には第２図ｂの流量比例信号が発生するが、こ
れには第２図ｃの電磁誘導ノイズ、同図ｄの商用
周波ノイズ及び同図ｅの電気化学的直流ノイズが
重畳する。そこで前置増幅器５の増幅出力を
MPX６ｃにより第２図ｆのタイミングａ，ｂ，
ｃ，ｄ，…で取込み且つADC６ｄでデジタル信
号にし、各タイミングでのサンプル値Va，Vb、
Vc、Vdを用いて次式(1)の演算をCPU６ａが行う
ことにより、ノイズ分を含まない流量値Viを得
ている。但し式(1)中のｋは比例定数である。 This case will be explained below based on the drawings. FIG. 1 shows the circuit configuration of this type of electromagnetic flowmeter. This electromagnetic flowmeter is a constant current driven, low frequency excitation type electromagnetic flowmeter that uses a microcomputer for signal processing. To briefly explain the basic configuration and operation of an electromagnetic flowmeter, reference numerals 1, 2, and 3 are an excitation coil, a measurement conduit, and a pair of electrodes, which constitute an electromagnetic flowmeter transmitter. 4, 5, and 6 are a buffer amplifier, a preamplifier, and an arithmetic control circuit, respectively, and these constitute an electromagnetic flowmeter converter. In this example, the arithmetic control circuit 6 is a microprocessor (hereinafter abbreviated as CPU). 6a, memory 6b, multiplexer (hereinafter referred to as
MPX) 6c, analog-to-digital converter (hereinafter referred to as ADC) 6d, digital-to-analog converter (hereinafter referred to as DAC)
6e and an input/output port (hereinafter abbreviated as I/O) 6f. Note that 6g is a data bus, 6h is an address bus, 6i is a control bus, and 6j and 6k are timing signals, respectively. In this example, in order to remove commercial frequency noise, the excitation circuit 7 is controlled by a timing signal 6j synchronized with the commercial power supply 8 to generate an excitation current having a frequency of 1/2, 1/4, 1/8, etc. of the commercial frequency. . Excitation current waveforms are positive/negative, positive/zero, negative/zero, positive/
Various types such as zero, negative/zero polarity, sine wave, triangular wave, trapezoidal wave, etc. are adopted, but here we will use a rectangular wave that repeats positive, zero, negative, and zero as shown in Figure 2 a. . In response to this excitation current, a flow rate proportional signal as shown in Figure 2b is generated between the electrodes, but this includes electromagnetic induction noise as shown in Figure 2c, commercial frequency noise as shown in Figure 2d, and electrochemical DC noise as shown in Figure 2e. Noise is superimposed. Therefore, the amplified output of preamplifier 5 is
By MPX6c, the timing a, b of Fig. 2 f,
Capture at c, d, ... and convert into digital signal at ADC6d, sample values Va, Vb, at each timing.
The CPU 6a calculates the following equation (1) using Vc and Vd, thereby obtaining a flow rate value Vi that does not include noise. However, k in formula (1) is a proportionality constant.
Vi＝ｋ（−Va＋3Vb−3Vc＋Vd） ……式(1)
つまり、各タイミングでのサンプル値には第２
図ｂ〜ｅの波形にて斜線を付した部分が成分とし
て含まれているが、電磁誘導ノイズは各サンプル
タイミングが励磁電流の極性変化時点から等時間
ｔであることにより、また商用周波ノイズはサン
プルタイミングが商用電源周波数に同期している
ことにより、更に電気化学的直流ノイズはサンプ
ルタイミングが等間隔であり励磁周期程度の短時
間ではサンプル毎に一定変化量ΔEで変化するも
のと見なせることにより、それぞれ式(1)の演算に
よつて各ノイズ成分が相殺されて除去される。な
お、演算結果の流量値ViはDAC６ｅ等により所
定の出力形式の信号として出力される。 Vi=k(-Va+3Vb-3Vc+Vd)...Formula (1) In other words, the sample value at each timing has the second
The shaded parts in the waveforms in Figures b to e are included as components, but electromagnetic induction noise is caused by the fact that each sample timing is equal time t from the point of polarity change of the excitation current, and commercial frequency noise is Because the sample timing is synchronized with the commercial power supply frequency, electrochemical DC noise can be considered to change by a constant amount of change ΔE for each sample over a short period of time, such as the excitation period, because the sample timing is at equal intervals. , each noise component is canceled out and removed by the calculation of equation (1). Note that the flow rate value Vi resulting from the calculation is outputted as a signal in a predetermined output format by the DAC 6e or the like.
さて、上述した信号処理だけでは流量値Viが
測定流体の平均流量に必らずしも比例しないこと
は前述の通りである。 Now, as described above, the flow rate value Vi is not necessarily proportional to the average flow rate of the measured fluid only by the signal processing described above.
そこで第１図の実施例では、測定流体に関する
粘度η及び密度ρについての外部からの各信号を
MPX６ｃより読込み、CPU６ａが
Re＝Ｄ・ρ・ｕ／η ……式(2)
の演算によりレイノルズ数Reを求め、先の流量
値Viに対して
V0＝Vi・｛１±Ｋ（Re）｝ ……式(3)
の補正を行つたのちDAC６ｅを通じてV0のアナ
ログ信号を出力する。但し、
式(2)中のＤは測定用管路２の内径、ｕは流速で
あるが、レイノルズ数Reの測定精度はViのそれ
に比較して大まかなもので良く、流量値Viより
得られる式(2)の値を用いれば足りる。また式(3)中
の補正係数±Ｋ（Re）は電磁流量計発信器自身の
磁界分布によつて異なるが、磁界分布が定まれば
レイノルズ数Reで決定され、例えば電磁流量計
を1m／ｓ程度の乱流域で水により校正した時と
各レイノルズ数Reにおける実液測定時とのスパ
ン誤差の関係式で求まり、Reの関数としてメモ
リ６ｂに記憶しておく。 Therefore, in the embodiment shown in FIG.
Read from MPX6c, CPU6a calculates Re=D・ρ・u/η...calculating the Reynolds number Re by formula (2), and calculates V 0 =Vi・{1±K(Re) for the previous flow rate value Vi. } ...After performing the correction according to equation (3), an analog signal of V 0 is outputted through the DAC 6e. However, in formula (2), D is the inner diameter of the measurement pipe 2, and u is the flow velocity, but the measurement accuracy of the Reynolds number Re may be rough compared to that of Vi, and can be obtained from the flow rate value Vi. It is sufficient to use the value of equation (2). Also, the correction coefficient ±K (Re) in equation (3) varies depending on the magnetic field distribution of the electromagnetic flowmeter transmitter itself, but once the magnetic field distribution is determined, it is determined by the Reynolds number Re. It is determined by the relational expression of the span error between when calibrating with water in a turbulent region of about s and when measuring the actual liquid at each Reynolds number Re, and is stored in the memory 6b as a function of Re.
式(3)による補正の実行は、CPU６ａ内部で式
(3)の演算を行うことによつても得られるが、第１
図の例の如くCPU６ａからの操作信号６ｌによ
り、前置増幅器５の負帰還要素βを補正係数±Ｋ
（Re）に応じて変化させるというゲイン調整によ
り達成することもできる。なお、CPU６ａの演
算等に必要なプログラムはメモリ６ｂに格納され
ている。 The correction using formula (3) is executed using the formula inside the CPU6a.
It can also be obtained by performing the calculation in (3), but the first
As shown in the example in the figure, the negative feedback element β of the preamplifier 5 is adjusted by the correction coefficient ±K by the operation signal 6l from the CPU 6a.
This can also be achieved by adjusting the gain by changing it according to (Re). Incidentally, programs necessary for calculations and the like of the CPU 6a are stored in the memory 6b.
以上の第１図に示す電磁流量計は、中心軸対称
の流れをベースとして適用されるレイノルズ数を
演算により算出して、これにより流量補正して精
度を確保しようとするものである。 The above-described electromagnetic flowmeter shown in FIG. 1 calculates the Reynolds number to be applied based on a centrally symmetrical flow, and corrects the flow rate based on this calculation to ensure accuracy.
しかし、既述のように微小口径の電磁流量計で
はその内径が小さいのでライニングされた導管の
内面に電極を面位置に固定するすることが難し
く、また円筒状の導管の側面に円柱状の電極を導
管の軸に直角に挿入する関係で電極の接液面とラ
イニングとの間に段差が生じるので、電極部近傍
での流れが乱れ、これが起電力に影響を及ぼして
誤差を発生させる。 However, as mentioned above, since the inner diameter of micro-diameter electromagnetic flowmeters is small, it is difficult to fix the electrodes in a flat position on the inner surface of the lined conduit. Because the electrode is inserted at right angles to the axis of the conduit, a step is created between the liquid contact surface of the electrode and the lining, which disrupts the flow near the electrode, which affects the electromotive force and causes errors.
このような場合は、測定流体のローカルな流れ
の乱れに起因して誤差が生じるので、第１図に示
すように中心軸対称流をベースとするレイノルズ
数Reで一義的に補正することができない面があ
る。 In such cases, errors occur due to local flow turbulence of the measured fluid, so it cannot be corrected uniquely using the Reynolds number Re, which is based on a centrally symmetrical flow, as shown in Figure 1. There is a side.
本発明は、以上の問題を解決するために、電磁
流量計において、測定流体の液種に関する識別情
報が外部から入力される情報入力端と、基準流体
により校正したときと先の液種における実液で測
定したときのスパン誤差との関係が補正係数の形
で格納された記憶手段と、先の識別情報に基づき
この記憶手段から読み出された先の補正係数によ
る補正演算を発信器からの信号に対して施す補正
演算手段とを備え、この補正演算はマイクロコン
ピユータにより実行してその補正結果を流量信号
として出力するようにしたものである。 In order to solve the above-mentioned problems, the present invention provides an information input terminal for inputting identification information regarding the liquid type of the measured fluid from the outside in an electromagnetic flowmeter, and an information input terminal for inputting identification information regarding the liquid type of the measured fluid, and an information input terminal for calibrating with a reference fluid and for the previous liquid type. A storage means in which the relationship with the span error when measuring with a liquid is stored in the form of a correction coefficient, and a correction calculation using the correction coefficient read from the storage means based on the identification information is performed from the transmitter. This correction calculation means is provided with a correction calculation means for applying to the signal, and the correction calculation is executed by a microcomputer and the correction result is outputted as a flow rate signal.
以下、本発明の実施例について説明する。第３
図は本発明の一実施例の回路構成を示す。この例
も第１図の例と同じくマイクロコンピユータを用
いた例である。したがつて電磁流量計としての基
本的な動作の説明は省略する。この例は測定流体
の種類によつてはそれの或る流量範囲内で補正係
数Ｋがほぼ一定とみなし得る場合が多いことに着
目したものである。つまり、種々の測定液種ｉに
応じてその補正係数±Kiを±の符号も含めて予
めメモリ６ｂに記憶させておき、外部から入力さ
れて液種を指定する識別信号Ｓにより対応する補
正係数±Kiを読み出して次式(4)の
V0＝Vi（１±Ki） ……式(4)
補正を行うのである。この例の電磁流量計は、バ
ツチ的に液種を変えて測定する場合に有効であ
る。但し、各液種ｉの補正係数±Kiは水による
検定値と実液による検定値との差から予め求めて
おく。なお、式(4)の補正の実行は第１図の場合と
同じくCPU６ａによる演算か、あるいは図示の
如く操作信号６ｌによる前置増幅器５のゲイン制
御により達成できる。 Examples of the present invention will be described below. Third
The figure shows a circuit configuration of an embodiment of the present invention. This example also uses a microcomputer, similar to the example shown in FIG. Therefore, explanation of the basic operation as an electromagnetic flowmeter will be omitted. This example focuses on the fact that depending on the type of fluid to be measured, the correction coefficient K can often be considered to be approximately constant within a certain flow rate range. That is, the correction coefficients ±Ki including the sign of ± are stored in advance in the memory 6b according to various types of liquid to be measured i, and the corresponding correction coefficients are determined by the identification signal S inputted from the outside and specifying the liquid type. ±Ki is read out and the following equation (4) V 0 =Vi (1±Ki)...Equation (4) is corrected. The electromagnetic flowmeter of this example is effective when measuring different liquid types in batches. However, the correction coefficient ±Ki for each liquid type i is determined in advance from the difference between the test value for water and the test value for actual liquid. Note that execution of the correction of equation (4) can be achieved by calculation by the CPU 6a as in the case of FIG. 1, or by controlling the gain of the preamplifier 5 using the operation signal 6l as shown.
以上、実施例と共に具体的に説明したように本
発明によれば、液種情報を外部から設定し、これ
から記憶手段に格納された測定流体の液種と基準
流体との差を補正する補正係数を用いてスパン誤
差をマイクロコンピユータで補正するようにした
ので、微小口径の電磁流量計で発生しやすいロー
カルな流れの乱れに起因するスパン差をも低コス
トで正確に補正することができる。 As described above in detail with the embodiments, according to the present invention, liquid type information is set externally, and a correction coefficient is used to correct the difference between the liquid type of the measured fluid stored in the storage means and the reference fluid. Since the span error is corrected by a microcomputer using , it is possible to accurately correct span differences caused by local flow disturbances that tend to occur in small-diameter electromagnetic flowmeters at low cost.
特に、本発明によれば、バツチ的に液種を変え
て測定する場合に有効である。 In particular, the present invention is effective when measuring by changing the liquid type in batches.
第１図はレイノルズ数を用いて補正する構成の
電磁流量計を説明するブロツク図、第２図は第１
図に示す電磁流量計の動作を説明する波形図、第
３図は本発明の１実施例の構成を示すブロツク図
である。
図面中、１は励磁コイル、２は測定用管路、３
は電極、５は前置増幅器、６ａはマイクロプロセ
ツサ、６ｂはメモリ、６ｃはマルチプレクサ、６
ｄはアナログ・デジタル変換器、６ｅはデジタ
ル・アナログ変換器、６ｆは入出力ポート、６ｌ
はゲイン制御用の信号、７は励振回路、８は商用
電源、V0は出力、ηは粘度を表わす信号、ρは
密度を表わす信号、Ｓは液種の識別信号、βは負
帰還要素である。
Figure 1 is a block diagram illustrating an electromagnetic flowmeter configured to compensate using the Reynolds number, and Figure 2 is a block diagram of an electromagnetic flowmeter configured to compensate using the Reynolds number.
FIG. 3 is a waveform diagram explaining the operation of the electromagnetic flowmeter shown in the figure, and FIG. 3 is a block diagram showing the configuration of one embodiment of the present invention. In the drawing, 1 is an excitation coil, 2 is a measurement pipe, and 3
are electrodes, 5 is a preamplifier, 6a is a microprocessor, 6b is a memory, 6c is a multiplexer, 6
d is an analog/digital converter, 6e is a digital/analog converter, 6f is an input/output port, 6l
is a signal for gain control, 7 is an excitation circuit, 8 is a commercial power supply, V 0 is an output, η is a signal representing viscosity, ρ is a signal representing density, S is a liquid type identification signal, and β is a negative feedback element. be.
Claims (1)
る識別情報が外部から入力される情報入力端と、
基準流体により校正したときと前記液種における
実液で測定したときのスパン誤差との関係が補正
係数の形で格納された記憶手段と、前記識別情報
に基づきこの記憶手段から読み出された前記補正
係数による補正演算を発信器からの信号に対して
施す補正演算手段とを備え、この補正演算はマイ
クロコンピユータにより実行してその補正結果を
流量信号として出力することを特徴とする電磁流
量計。1 In an electromagnetic flowmeter, an information input terminal into which identification information regarding the liquid type of the measured fluid is input from the outside;
a storage means in which the relationship between the span error when calibrated with a reference fluid and when measured with an actual liquid of the liquid type is stored in the form of a correction coefficient; An electromagnetic flowmeter comprising a correction calculation means for applying a correction calculation to a signal from a transmitter using a correction coefficient, the correction calculation being executed by a microcomputer and outputting the correction result as a flow rate signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10811081A JPS5810610A (en) | 1981-07-13 | 1981-07-13 | Electromagnetic flowmeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10811081A JPS5810610A (en) | 1981-07-13 | 1981-07-13 | Electromagnetic flowmeter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5810610A JPS5810610A (en) | 1983-01-21 |
| JPH0421128B2 true JPH0421128B2 (en) | 1992-04-08 |
Family
ID=14476141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10811081A Granted JPS5810610A (en) | 1981-07-13 | 1981-07-13 | Electromagnetic flowmeter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5810610A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6148319U (en) * | 1984-09-03 | 1986-04-01 | ||
| JPH01294112A (en) * | 1988-05-19 | 1989-11-28 | Bridgestone Corp | All-directional conveyor belt |
| US4961348A (en) * | 1988-12-16 | 1990-10-09 | Ulrich Bonne | Flowmeter fluid composition correction |
-
1981
- 1981-07-13 JP JP10811081A patent/JPS5810610A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5810610A (en) | 1983-01-21 |
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