JPH08233630A - Liquid level measuring device - Google Patents
Liquid level measuring deviceInfo
- Publication number
- JPH08233630A JPH08233630A JP3482895A JP3482895A JPH08233630A JP H08233630 A JPH08233630 A JP H08233630A JP 3482895 A JP3482895 A JP 3482895A JP 3482895 A JP3482895 A JP 3482895A JP H08233630 A JPH08233630 A JP H08233630A
- Authority
- JP
- Japan
- Prior art keywords
- density
- liquid level
- tube
- liquid
- differential pressure
- 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
Landscapes
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Abstract
(57)【要約】
【目的】 液体密度が変化する液体液位を精度良く測定
する装置を提供することにある。
【構成】 第一，第三のチューブＴ１，Ｔ３の液位差圧
Ｐ２を液位リニアライズ処理部Ｒ２を介し密度補正演算
回路ＭＩ１に入力する。また、第一，第二のチューブＴ
１，Ｔ２の密度差圧Ｐ１から求まる密度値Ｄ１を密度出
力回路ＭＯ、密度リニアライズ処理部Ｒ１を介しホール
ド回路Ｈに入力する。そして、ホールド回路Ｈでは（Ｌ
０＋β）≦液位Ｌかつ液位Ｌ≦（Ｌ１＋α）の条件下で
液位Ｌが下がる時の密度値Ｄ１を保持し出力する。そし
て、密度補正演算回路ＭＩ１では、液位差圧Ｐ２を（Ｌ
０＋β）で減算し、そして液体の最大密度値Ｄ０で除算
し最大密度の液位Ｌ２を求める。さらに、密度比回路Ａ
のＤ１／Ｄ０の値でＬ２を除算し、（Ｌ０＋β）を加算
して求めるべき液位Ｌを得る。
(57) [Summary] [Objective] To provide an apparatus for accurately measuring a liquid level in which a liquid density changes. [Structure] The liquid level differential pressure P2 of the first and third tubes T1, T3 is input to a density correction arithmetic circuit MI1 via a liquid level linearization processing unit R2. Also, the first and second tubes T
The density value D1 obtained from the density differential pressure P1 of 1 and T2 is input to the hold circuit H via the density output circuit MO and the density linearization processing unit R1. Then, in the hold circuit H, (L
0 + β) ≦ liquid level L and liquid level L ≦ (L1 + α) The density value D1 when the liquid level L decreases is held and output. Then, in the density correction calculation circuit MI1, the liquid level differential pressure P2 is set to (L
0 + β) and then divide by the maximum liquid density value D0 to obtain the maximum density liquid level L2. Furthermore, the density ratio circuit A
L2 is divided by the value of D1 / D0, and (L0 + β) is added to obtain the liquid level L to be obtained.
Description
【０００１】[0001]
【産業上の利用分野】本発明は、タンク中の密度の変化
する液体の液位測定装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid level measuring device for a liquid of varying density in a tank.
【０００２】[0002]
【従来の技術】タンクの中に存在する密度が変化する液
体の液位を測定するために、従来の液位測定装置は図３
に示す構成となっている。タンク１の中に三本のチュー
ブを挿入されている。第一のチューブＴ１の先端はタン
ク１の底からＬ０の位置の下部に、第二のチューブＴ２
の先端は第一のチューブＴ１の上側のタンク１の底から
Ｌ１の位置の液体中に、第三のチューブＴ３の先端は、
タンクの底からＬＫの位置であるタンク上部の空気中に
設置されている。第一のチューブＴ１と第二のチューブ
Ｔ２との間に発生する密度差圧Ｐ１から液体の密度値Ｄ
１を密度出力回路ＭＯにより算出する。また、第一のチ
ューブＴ１と第三のチューブＴ３との間に発生する液位
差圧Ｐ２を、前記密度値Ｄ１で除算することで、タンク
中に充填された液体の液位Ｌを測定する。密度値Ｄ１
は、以下の式（Ａ）によって計算可能であり、液位Ｌ
は、式（Ａ）によって計算される密度値Ｄ１を使用して
式（Ｂ）によって計算が可能である。2. Description of the Related Art In order to measure the liquid level of a liquid of varying density existing in a tank, a conventional liquid level measuring device is shown in FIG.
The configuration is shown in. Three tubes are inserted in the tank 1. The tip of the first tube T1 is located at the lower part of the position L0 from the bottom of the tank 1 and the second tube T2.
The tip of the third tube T3 is in the liquid at the position L1 from the bottom of the tank 1 above the first tube T1, and the tip of the third tube T3 is
It is installed in the air above the tank, which is LK from the bottom of the tank. The density value D of the liquid from the density differential pressure P1 generated between the first tube T1 and the second tube T2.
1 is calculated by the density output circuit MO. Further, the liquid level differential pressure P2 generated between the first tube T1 and the third tube T3 is divided by the density value D1 to measure the liquid level L of the liquid filled in the tank. . Density value D1
Can be calculated by the following formula (A), and the liquid level L
Can be calculated according to equation (B) using the density value D1 calculated according to equation (A).
【０００３】[0003]
【数１】 Ｄ１＝１０００・Ｐ１／（Ｌ１−Ｌ０） …… （Ａ） Ｌ＝１０００・Ｐ２／Ｄ１＋Ｌ０ …… （Ｂ） 但し、Ｐ１，Ｐ２の単位：mmＡq Ｄ１の単位 ：kg／ｍ3 Ｌ０，Ｌ１の単位：mm とする。[Equation 1] D1 = 1000 · P1 / (L1-L0) (A) L = 1000 · P2 / D1 + L0 (B) However, the unit of P1 and P2: mmAq The unit of D1: kg / m3 L0, The unit of L1 is mm.
【０００４】上記（Ａ），（Ｂ）式の関係を図４の液位
測定装置ＳＥ１の演算回路構成図を参照して説明する。
密度センサＤＴにより得られる密度差圧Ｐ１は、密度出
力回路ＭＯによって上記（Ａ）式から得られる密度値Ｄ
１を算出し、密度リニアライズ処理部Ｒ１を通して工学
値変換された後、レンジの上下限値を制限するフィルタ
回路Ｆ１を通り、密度値指示計ＳＤＩの表示として使用
される。一方、差圧センサＬＴによって測定された液位
差圧Ｐ２は、液位リニアライズ処理部Ｒ２を通して工学
値変換がなされ、除算回路Ｗ１により密度値Ｄ１で割ら
れた後、加算回路Ｋ１でＬ０が加えられ、密度補正され
た求めるべき液位Ｌを算出し、この値は液位指示計ＳＬ
１で表現される。このとき、密度値Ｄ１が上限値Ｄmax
と下限値Ｄmin の間の値をとるとすれば、密度値指示計
ＳＤＩのレンジは、The relationship between the above equations (A) and (B) will be described with reference to the arithmetic circuit block diagram of the liquid level measuring device SE1 shown in FIG.
The density differential pressure P1 obtained by the density sensor DT is the density value D obtained from the above equation (A) by the density output circuit MO.
1 is calculated, an engineering value is converted through the density linearization processing unit R1, and then the value is passed through a filter circuit F1 that limits the upper and lower limit values of the range and used as a display of the density value indicator SDI. On the other hand, the liquid level differential pressure P2 measured by the differential pressure sensor LT is subjected to engineering value conversion through the liquid level linearization processing unit R2, divided by the density value D1 by the division circuit W1, and then L0 is changed by the addition circuit K1. A liquid level L to be obtained, which is added and density-corrected, is calculated, and this value is used as a liquid level indicator SL.
Expressed as 1. At this time, the density value D1 is the upper limit value Dmax
And the lower limit value Dmin, the range of the density value indicator SDI is
【０００５】[0005]
【数２】 Ｄmin ＜Ｄ１＜Ｄmax …… （Ｃ） であり、求めるべき液位Ｌは[Equation 2] Dmin <D1 <Dmax (C), and the liquid level L to be obtained is
【０００６】[0006]
【数３】 1000・Ｐ２／Ｄmax ＋Ｌ０＜Ｌ＜1000・Ｐ２／Ｄmin ＋Ｌ０ … （Ｄ） と表され、液位指示計ＳＬＩのレンジが求められる。[Expression 3] 1000 · P2 / Dmax + L0 <L <1000 · P2 / Dmin + L0 (D), and the range of the liquid level indicator SLI is obtained.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、この従
来の方法では、密度値Ｄ１は液位がＬ１よりも低い位置
では差圧Ｐ１が測定できず、このため液位Ｌは液位差圧
Ｐ２の上限値をＰmax 、下限値をＰmin とすれば、以下
の（Ｅ）式の、However, according to this conventional method, the density value D1 cannot measure the differential pressure P1 at a position where the liquid level is lower than L1. Therefore, the liquid level L does not correspond to the liquid level differential pressure P2. Assuming that the upper limit value is Pmax and the lower limit value is Pmin,
【０００８】[0008]
【数４】 Ｌ１＜Ｌ＜1000・Ｐmax ／Ｄmin ＋Ｌ０ …… （Ｅ） のレンジ範囲でしか表現できなかった。また、この式で
はＰmax ，Ｄmin がどのような関係を有するか分から
ず、タンク１に入りうる最大の液位をレンジの上限にと
るしかなかった。このため、従来の計算法による装置に
おいては、液位Ｌ１以下の値は測定不可能であり、レン
ジ決定が困難であった。[Equation 4] L1 <L <1000.Pmax / Dmin + L0 ... (E) It could be expressed only in the range. Further, in this formula, it is not possible to know what relationship Pmax and Dmin have, and the maximum liquid level that can enter the tank 1 has to be taken as the upper limit of the range. For this reason, in the device by the conventional calculation method, the value below the liquid level L1 cannot be measured, and it is difficult to determine the range.
【０００９】[0009]
【課題を解決するための手段】 ［請求項１］記載の発明は、チューブの先端がタンクの
底部付近に位置されている第一のチューブと、第一のチ
ューブの先端より上方の液体中の位置に設定されている
第二のチューブと、チューブの先端がタンク内の空気中
に設定されている第三のチューブと、前記第一のチュー
ブと第二のチューブとの間に発生する差圧から液体密度
を検出する密度センサと、前記第一のチューブと第三の
チューブとの間に発生する差圧を検出する差圧センサ
と、前記差圧センサにて検出される差圧を前記密度セン
サにて検出される密度で除算することでタンクの中に存
在する密度が変化する液体の液位を測定する液位測定装
置において、タンク内の液位が第二のチューブの先端以
下に下がった場合、第二のチューブの先端において下が
る直前に検出される密度を記憶し、この記憶された密度
に基づいてタンク内の液位の密度補正を行うことを特徴
とする。Means for Solving the Problems [Claim 1] The invention according to claim 1 includes: a first tube in which the tip of the tube is located near the bottom of the tank; and a liquid in a liquid above the tip of the first tube. The second tube set to the position, the third tube whose tip is set in the air in the tank, and the differential pressure generated between the first tube and the second tube. A density sensor for detecting a liquid density from the differential tube, a differential pressure sensor for detecting a differential pressure generated between the first tube and a third tube, and a differential pressure detected by the differential pressure sensor for the density In a liquid level measuring device that measures the liquid level of the liquid whose density changes in the tank by dividing by the density detected by the sensor, the liquid level in the tank drops below the tip of the second tube. The second tube tip It is characterized in that the density detected immediately before the drop is stored, and the density of the liquid level in the tank is corrected based on the stored density.
【００１０】［請求項２］記載の発明は、［請求項１］
記載の発明において、Ｌをタンク内の液位、Ｌ０を第一
のチューブの先端位置、Ｌ１を第二のチューブの先端位
置、α，βをタンク固有の値としたとき、（Ｌ０＋β≦
ＬかつＬ≦Ｌ１＋α）条件に基づき第二のチューブの先
端の密度を記憶することを特徴とする。The invention according to [Claim 2] is [Claim 1].
In the invention described above, where L is the liquid level in the tank, L0 is the tip position of the first tube, L1 is the tip position of the second tube, and α and β are values unique to the tank, (L0 + β ≦
L and L ≦ L1 + α) conditions are stored based on the density of the tip of the second tube.
【００１１】［請求項３］記載の発明は、［請求項
１］，［請求項２］記載の発明において、 設計上の密
度変化レンジの最大値に基づいて計算される液位の上限
値および下限値とすることで密度補正後の液位を表示す
る表示器を設けたことを特徴とする。The invention described in [Claim 3] is the invention described in [Claim 1] and [Claim 2], in which the upper limit value of the liquid level calculated based on the maximum value of the designed density change range and It is characterized in that an indicator for displaying the liquid level after density correction by providing the lower limit value is provided.
【００１２】[0012]
【作用】今まで測定が不可能であった液位Ｌ０＜Ｌ＜Ｌ
１を予測値ではあるが測定すること、及び液位の指示計
の値を必ず上限値から下限値の間に連続して変化するよ
うにしたことを可能にすることができる。[Function] Liquid level L0 <L <L that could not be measured until now
It is possible to measure 1 although it is a predicted value, and to make the value of the liquid level indicator continuously change between the upper limit value and the lower limit value.
【００１３】[0013]
【実施例】本発明の実施例を図１と図２を参照して、以
下に説明する。図２は、本実施例の液位測定装置の演算
回路構成図を示すものである。図１は、本実施例の構成
図を示すものである。Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 2 shows an arithmetic circuit configuration diagram of the liquid level measuring device of the present embodiment. FIG. 1 shows a block diagram of this embodiment.
【００１４】図１において、タンク１中の３本のチュー
ブのうち、第二のチューブＴ２の先端（タンク１の底か
らＬ１に位置する先端）の上側の液体中にて、このチュ
ーブの先端の上方近傍の位置を（Ｌ１＋α）とし、液体
がＬ１にあるときにも液位が波打ち等によって（Ｌ１＋
α）以上には液位が上がらない位置を定めておく。ま
た、タンク１中の液体中の下側に位置する第一のチュー
ブＴ１の先端（タンク１の底からＬ０の位置）の上方近
傍の位置を（Ｌ０＋β）とし、液体がＬ０にあるときに
も液位が波打ち等によって（Ｌ０＋β）以上には液位が
上がらない位置を定めておく。また、予め使用する液体
が決定していれば、計算によって定められる液体の最大
密度は予測可能であり、その値をＤ０とする。In FIG. 1, among the three tubes in the tank 1, in the liquid above the tip of the second tube T2 (tip located at L1 from the bottom of the tank 1), the tip of this tube The position near the upper side is (L1 + α), and when the liquid is at L1, the liquid level is (L1 + α)
Set a position where the liquid level does not rise above α). Further, the position near the upper end of the first tube T1 (the position L0 from the bottom of the tank 1) of the first tube T1 located on the lower side in the liquid in the tank 1 is (L0 + β), and the liquid is also in L0. The position where the liquid level does not rise above (L0 + β) due to waviness or the like is determined. Further, if the liquid to be used is determined in advance, the maximum density of the liquid determined by calculation can be predicted, and its value is set to D0.
【００１５】図２の液位測定装置ＳＥ２の演算回路構成
図を参照して説明する。密度センサＤＴから得られる密
度差圧Ｐ１は、密度出力回路ＭＯにより演算され密度値
Ｄ１となり、密度リニアライズ処理部Ｒ１を通して、工
学値変換がなされる。ただし、この密度値Ｄ１は液位が
以下の式（Ｈ）Description will be made with reference to the arithmetic circuit configuration diagram of the liquid level measuring device SE2 in FIG. The density differential pressure P1 obtained from the density sensor DT is calculated by the density output circuit MO to become the density value D1, and the engineering value conversion is performed through the density linearization processing unit R1. However, this density value D1 is expressed by the following formula (H)
【００１６】[0016]
【数５】Ｌ１＋α＞Ｌ …… （Ｆ） の時のみ信用できる値である。しかし、実際の液位を測
るためには、少なくとも下限値Ｌ０＋βまでの値を取る
必要がある。このため、液位が以下の式（Ｉ）## EQU00005 ## Only when L1 + .alpha.> L ... (F) is a credible value. However, in order to measure the actual liquid level, it is necessary to take a value at least up to the lower limit value L0 + β. Therefore, the liquid level is represented by the following formula (I)
【００１７】[0017]
【数６】Ｌ０＋β≦Ｌ≦Ｌ１＋α …… （Ｇ） の範囲ではＬ１＋αでの密度値Ｄ１を使用することに
し、タンク下部での密度をＬ１＋αでの密度値Ｄ１での
一定の値に保持しておくホールド回路Ｈを設ける。この
ホールド回路Ｈは、式（Ｉ）の条件式（ａ）の時、つま
り[Equation 6] L0 + β ≦ L ≦ L1 + α (D) In the range of (G), the density value D1 at L1 + α is used, and the density at the lower part of the tank is kept constant at the density value D1 at L1 + α. A hold circuit H is provided. This hold circuit H has the following condition when the conditional expression (a) of the expression (I) is satisfied, that is,
【００１８】[0018]
【数７】 Ｌ０＋β≦Ｌ かつ …… （ａ） Ｌ≦Ｌ１＋α のフラグの条件で、液位が下がる時に出力されていた信
号を、## EQU00007 ## L0 + .beta..ltoreq.L and (a) Under the condition of the flag L.ltoreq.L1 + .alpha.
【００１９】[0019]
【数８】Ｌ≦Ｌ１＋α 時点の密度Ｄ１で保持する保持回路Ｋと、条件式（ａ）
の条件の場合以外は、測定されている密度値をそのまま
出力する切替回路ＳＥＬを含んでいる。[Equation 8] A holding circuit K that holds the density D1 at L ≦ L1 + α and the conditional expression (a)
A switch circuit SEL that outputs the measured density value as it is is included except under the condition of.
【００２０】このホールド回路Ｈより出力される密度値
Ｄ１は、予め計算によって示される予測最大密度と最低
密度の間にあることが前提条件となるため、この上下限
値で値を制限するフィルタ回路Ｆ１を通す。つまり、フ
ィルタ回路Ｆ１の出力である密度値Ｄ１は、上下限値を
それぞれ、Ｄmax ，Ｄmin とすればSince the density value D1 output from the hold circuit H must be between the predicted maximum density and the minimum density, which are previously calculated, the filter circuit limits the value with the upper and lower limit values. Pass F1. That is, the density value D1 which is the output of the filter circuit F1 can be obtained by setting the upper and lower limits to Dmax and Dmin, respectively.
【００２１】[0021]
【数９】Ｄmin ＜Ｄ１＜Ｄmax …… （Ｉ） となり、この密度値Ｄ１はレンジＤmin からＤmax をも
つ密度値指示計ＳＤＩに表示される。## EQU9 ## Dmin <D1 <Dmax (I) and this density value D1 is displayed on the density value indicator SDI having the range Dmin to Dmax.
【００２２】一方、差圧センサＬＴによって測定された
液位差圧Ｐ２は、液位リニアライズ処理部Ｒ２を通し
て、工学変換された後、減算回路Ｇ２でＬ０＋βを減算
された後、液体の最大密度値Ｄ０で除算し、除算回路Ｗ
２で以下の式（Ｉ）が計算され、仮の最大密度の液位Ｌ
２を求め、On the other hand, the liquid level differential pressure P2 measured by the differential pressure sensor LT is subjected to engineering conversion through the liquid level linearization processing unit R2, and then L0 + β is subtracted by the subtraction circuit G2, and then the maximum liquid density is obtained. Divide by the value D0 and divide by W
The following formula (I) is calculated in 2, and the liquid level L of the temporary maximum density is calculated.
Ask for 2,
【００２３】[0023]
【数１０】 Ｌ２＝1000・Ｐ２／Ｄmax ＝1000・Ｐ２／Ｄ０ …… （Ｊ） となる。この（Ｉ）式より得られるＬ２により、求める
べき液位Ｌは、前記で得られたＤ１を使用し、密度比回
路Ａから得られるＤ１／Ｄ０の値で割った後、Ｌ０＋β
を加えたものになる。これを式で表せば、[Equation 10] L2 = 1000 · P2 / Dmax = 1000 · P2 / D0 (J) The liquid level L to be obtained by using L2 obtained from the formula (I) is L0 + β after using D1 obtained above and dividing by the value of D1 / D0 obtained from the density ratio circuit A.
Will be added. If this is expressed by an equation,
【００２４】[0024]
【数１１】 Ｌ＝Ｌ２／（Ｄ１／Ｄ０）＋Ｌ０＋β ＝1000・Ｐ２／Ｄ１＋Ｌ０＋β …… （Ｋ） として決定でき、液位Ｌは”液位差圧Ｐ２が最大でかつ
最大密度Ｄ０の時”に最大となり、測定下限値であるＬ
０＋βの値Ｌmin 、測定上限値の値をＬmax とすれば、[Formula 11] L = L2 / (D1 / D0) + L0 + β = 1000 · P2 / D1 + L0 + β (K), and the liquid level L is "when the liquid level differential pressure P2 is maximum and the maximum density D0". L is the maximum and the lower limit of measurement
If the value Lmin of 0 + β and the value of the upper limit of measurement are Lmax,
【００２５】[0025]
【数１２】 Ｌmin ＝Ｌ０＋β …… （Ｌ） は明白であり、Ｐ２の上下限値を、それぞれＰmax ，Ｐ
min とすればLmin = L0 + β (L) is clear, and the upper and lower limit values of P2 are Pmax and P, respectively.
If min
【００２６】[0026]
【数１３】 Ｌmax ＝1000・Ｐmax ／Ｄ０＋Ｌ０＋β …… （Ｍ） となる。これにより、従来、液位を液位指示計ＳＬＩで
表現するときに、困難であったレンジの幅を（Ｌ），
（Ｍ）の式により、次式（Ｎ）(13) Lmax = 1000 · Pmax / D0 + L0 + β (M) As a result, when the liquid level is conventionally expressed by the liquid level indicator SLI, the range width which has been difficult is (L),
From the formula (M), the following formula (N)
【００２７】[0027]
【数１４】 Ｌmin ＝Ｌ０＋β＜Ｌ＜1000・Ｐmax ／Ｄ０＋Ｌ０＋β ……（Ｎ） で指定できることとなる。[Formula 14] Lmin = L0 + β <L <1000 · Pmax / D0 + L0 + β (N)
【００２８】[0028]
【発明の効果】これらの装置により、ホールド回路Ｈを
つけることで、従来から課題となってきたチューブ上側
値Ｌ１以下で、かつチューブ下側値Ｌ０以上の液位の測
定が可能となり、予め設定される最大密度Ｄ０を使用す
ることで、液位指示計Ｌ１のレンジの上下限値を決定す
ることができる。EFFECTS OF THE INVENTION By providing a hold circuit H with these devices, it is possible to measure the liquid level below the tube upper side value L1 and above the tube lower side value L0, which has been a problem in the past, and it is preset. The upper and lower limits of the range of the liquid level indicator L1 can be determined by using the maximum density D0.
【図面の簡単な説明】[Brief description of drawings]
【図１】本実施例の全体構成図。FIG. 1 is an overall configuration diagram of this embodiment.
【図２】本実施例の液位測定装置の演算回路構成図。FIG. 2 is a configuration diagram of an arithmetic circuit of the liquid level measuring device according to the present embodiment.
【図３】従来の全体構成図。FIG. 3 is a conventional overall configuration diagram.
【図４】従来の液位測定装置の演算回路構成図。FIG. 4 is a configuration diagram of an arithmetic circuit of a conventional liquid level measuring device.
ＤＴ…密度センサ、ＬＴ…差圧センサ、ＳＥ１，ＳＥ２
…液位測定装置、Ｈ…ホールド回路、ＭＩ１，ＭＩ２…
密度補正演算回路、Ｒ１…密度リニアライズ処理部、Ｒ
２…液位リニアライズ処理部、ＭＯ…密度出力回路DT ... Density sensor, LT ... Differential pressure sensor, SE1, SE2
... Liquid level measuring device, H ... Hold circuit, MI1, MI2 ...
Density correction arithmetic circuit, R1 ... Density linearization processing unit, R
2 ... Liquid level linearization processing unit, MO ... Density output circuit
Claims (3)
置されている第一のチューブと、第一のチューブの先端
より上方の液体中の位置に設定されている第二のチュー
ブと、チューブの先端がタンク内の空気中に設定されて
いる第三のチューブと、前記第一のチューブと第二のチ
ューブとの間に発生する差圧から液体密度を検出する密
度センサと、前記第一のチューブと第三のチューブとの
間に発生する差圧を検出する差圧センサと、前記差圧セ
ンサにて検出される差圧を前記密度センサにて検出され
る密度で除算することでタンクの中に存在する密度が変
化する液体の液位を測定する液位測定装置において、タ
ンク内の液位が第二のチューブの先端以下に下がった場
合、第二のチューブの先端において下がる直前に検出さ
れる密度を記憶し、この記憶された密度に基づいてタン
ク内の液位の密度補正を行うことを特徴とする液位測定
装置。1. A first tube whose tip is located near the bottom of the tank, a second tube which is set at a position in the liquid above the tip of the first tube, and A third tube whose tip is set in the air in the tank, a density sensor for detecting the liquid density from the differential pressure generated between the first tube and the second tube, and the first A differential pressure sensor that detects the differential pressure generated between the tube and the third tube, and the differential pressure detected by the differential pressure sensor divided by the density detected by the density sensor In a liquid level measuring device that measures the liquid level of the liquid in which the density changes, if the liquid level in the tank falls below the tip of the second tube, it is detected immediately before it falls at the tip of the second tube. Remember the density A liquid level measuring device characterized by performing density correction of a liquid level in a tank based on the stored density.
ーブの先端位置、Ｌ１を第二のチューブの先端位置、
α，βをタンク固有の値としたとき、下記条件に基づき
第二のチューブの先端の密度を記憶することを特徴とす
る請求項１記載の液位測定装置。 Ｌ０＋β≦Ｌ かつ Ｌ≦Ｌ１＋α2. L is the liquid level in the tank, L0 is the tip position of the first tube, L1 is the tip position of the second tube,
The liquid level measuring device according to claim 1, wherein the density of the tip of the second tube is stored based on the following conditions, where α and β are values specific to the tank. L0 + β ≦ L and L ≦ L1 + α
に基づいて計算される液位の上限値および下限値とする
ことで密度補正後の液位を表示する表示器を設けたこと
を特徴とする請求項１または請求項２記載の液位測定装
置。3. An indicator is provided for displaying the liquid level after density correction by setting the upper limit value and the lower limit value of the liquid level calculated based on the maximum value of the designed density change range of the liquid. The liquid level measuring device according to claim 1 or 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03482895A JP3529474B2 (en) | 1995-02-23 | 1995-02-23 | Liquid level measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03482895A JP3529474B2 (en) | 1995-02-23 | 1995-02-23 | Liquid level measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08233630A true JPH08233630A (en) | 1996-09-13 |
| JP3529474B2 JP3529474B2 (en) | 2004-05-24 |
Family
ID=12425066
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03482895A Expired - Lifetime JP3529474B2 (en) | 1995-02-23 | 1995-02-23 | Liquid level measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3529474B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1286105A3 (en) * | 2001-08-07 | 2003-06-25 | Chart, Inc. | Differential pressure gauge for cryogenic fluids which selects a density value based on pressure measurement |
| CN102080979A (en) * | 2010-11-18 | 2011-06-01 | 杭州中美华东制药有限公司 | Method for measuring liquid level of fermentation tank |
| CN104236669A (en) * | 2014-05-26 | 2014-12-24 | 罗湘利 | High-accuracy liquid level sensor and liquid level remote-measuring and remote-controlling instrument |
-
1995
- 1995-02-23 JP JP03482895A patent/JP3529474B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6782339B2 (en) | 2000-07-31 | 2004-08-24 | Chart Industries, Inc. | Differential pressure gauge for cryogenic fluids which selects a density value based on pressure measurement |
| EP1286105A3 (en) * | 2001-08-07 | 2003-06-25 | Chart, Inc. | Differential pressure gauge for cryogenic fluids which selects a density value based on pressure measurement |
| CN102080979A (en) * | 2010-11-18 | 2011-06-01 | 杭州中美华东制药有限公司 | Method for measuring liquid level of fermentation tank |
| CN104236669A (en) * | 2014-05-26 | 2014-12-24 | 罗湘利 | High-accuracy liquid level sensor and liquid level remote-measuring and remote-controlling instrument |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3529474B2 (en) | 2004-05-24 |
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