JPH0246885B2 - - Google Patents
Info
- Publication number
- JPH0246885B2 JPH0246885B2 JP59069858A JP6985884A JPH0246885B2 JP H0246885 B2 JPH0246885 B2 JP H0246885B2 JP 59069858 A JP59069858 A JP 59069858A JP 6985884 A JP6985884 A JP 6985884A JP H0246885 B2 JPH0246885 B2 JP H0246885B2
- Authority
- JP
- Japan
- Prior art keywords
- flip
- circuit
- clock
- liquid level
- flop
- 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 - Lifetime
Links
- 239000007788 liquid Substances 0.000 claims description 25
- 239000004020 conductor Substances 0.000 claims description 5
- 239000011295 pitch Substances 0.000 claims 1
- 238000001514 detection method Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 8
- 230000003111 delayed effect Effects 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 230000008054 signal transmission Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/26—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields
- G01F23/263—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields by measuring variations in capacitance of capacitors
- G01F23/266—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields by measuring variations in capacitance of capacitors measuring circuits therefor
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Electromagnetism (AREA)
- Thermal Sciences (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Description
【発明の詳細な説明】
本発明は液位をデジタル信号で直接取り出せる
ようにした液位計測装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid level measuring device that can directly obtain liquid level as a digital signal.
従来液位計測装置としては、フロートを用いた
ものや、静電容量式で信号をアナログ量で取り出
す方式のものがあつた。 Conventional liquid level measuring devices include those that use floats and those that use capacitance to extract signals in analog quantities.
しかし、フロート式は機械的構成部を備えるた
め、故障が起きた時修理が困難であり、また静電
容量を用いたアナログ式の方法では高精度のもの
とするには極めて高価につくという欠点がある。 However, since the float type has mechanical components, it is difficult to repair when a failure occurs, and the analog method using capacitance is extremely expensive to achieve high precision. There is.
本発明は静電容量の違いにより検出された液位
を直接デジタル量で取り出せるようにしたもの
で、機械的構成部分が全くなく、高精度の液位計
測装置を安価に提供できるようにした。 The present invention enables the liquid level detected by the difference in capacitance to be obtained directly in digital form, and has no mechanical components at all, making it possible to provide a high-precision liquid level measuring device at a low cost.
以下本発明を実施例図に基いて説明する。 The present invention will be explained below based on embodiment figures.
第１図において、底面が閉塞した保護筒１に、
液流入口２ａを下部に有する電極収納管２が貫通
し、同電極収納管２内には相対向したコンデンサ
用の一対の電極３ａと3b、４ａと４ｂ、５ａと
５ｂ、６ａと６ｂ、７ａと７ｂを設けてある。各
電極の一方の極３ｂ〜７ｂは保護筒１内で全て接
地され、他方の極３ａ〜７ａは、保護筒１内にあ
るフリツプフロツプ回路８，９，１０，１１，１
２の各クロツク端CKと、抵抗１３，１４，１５，
１６，１７を介してクロツク入力端CKIに接続さ
れている。 In FIG. 1, in the protective tube 1 whose bottom surface is closed,
An electrode housing tube 2 having a liquid inlet 2a at the bottom passes through the electrode housing tube 2, and inside the electrode housing tube 2, a pair of opposing electrodes for capacitors 3a and 3b, 4a and 4b, 5a and 5b, 6a and 6b, 7a are installed and 7b are provided. One pole 3b to 7b of each electrode is all grounded inside the protective tube 1, and the other pole 3a to 7a are connected to flip-flop circuits 8, 9, 10, 11, 1 inside the protective tube 1.
2 clock ends CK and resistors 13, 14, 15,
16 and 17 to the clock input terminal CKI.
また各フリツプフロツプ回路のＤ入力端は、フ
リツプフロツプ回路８のＤ入力端だけが接地さ
れ、他は全て１つ前のフリツプフロツプ回路のＱ
出力端に接続されており、これによりシフトレジ
スタを形成している。 Also, among the D input terminals of each flip-flop circuit, only the D input terminal of flip-flop circuit 8 is grounded, and all the others are grounded.
It is connected to the output end, thereby forming a shift register.
イニシヤル入力端INTには、フリツプフロツ
プ回路８のみがセツト入力端Ｓを接続してあるが
他のフリツプフロツプ回路は全てリセツト端Ｒを
接続してあり、レベル検出端LVEは各抵抗２２，
２３，２４，２５と、これらに直列に接続された
ダイオード１８，１９，２０，２１を介して各フ
リツプフロツプ回路のＱ端に接続してある。 Only the flip-flop circuit 8 has the set input terminal S connected to the initial input terminal INT, but all other flip-flop circuits have the reset terminal R connected to the initial input terminal INT, and the level detection terminal LVE is connected to each resistor 22,
23, 24, 25 and diodes 18, 19, 20, 21 connected in series to the Q terminal of each flip-flop circuit.
次に本発明の回路動作について説明する。 Next, the circuit operation of the present invention will be explained.
第１図において、電極６，７が液中に没してい
ると、空中にある電極３，４，５に比べて電極
６，７の静電容量は、液体の比誘電率をεSとする
とεS倍となる。 In Fig. 1, when electrodes 6 and 7 are submerged in the liquid, the capacitance of electrodes 6 and 7 is smaller than that of electrodes 3, 4, and 5 in the air, and the relative permittivity of the liquid is ε S. Then, it becomes ε S times.
ここでクロツク入力端CKIよりクロツクパルス
を入力すると、空気の静電容量を有する電極３，
４，５に接続されたａ、ｂ、ｃ点の波形は、第２
図のように元のクロツクパルスよりt1時間遅れた
クロツク波形となる。ところが液により増大した
静電容量を持つ電極６，７に接続されたｄ、ｅ点
の波形は、同じく第２図のように元のクロツク波
形よりさらにt1＋t2時間遅れた波形を示す。 Here, when a clock pulse is input from the clock input terminal CKI, the electrode 3, which has an air capacitance,
The waveforms of points a, b, and c connected to
As shown in the figure, the clock waveform is delayed by t1 hours from the original clock pulse. However, the waveforms at points d and e, which are connected to electrodes 6 and 7 whose capacitance has been increased by the liquid, show a waveform that is further delayed by t 1 +t 2 hours from the original clock waveform, as shown in FIG.
このためフリツプフロツプ回路１１，１２はフ
リツプフロツプ回路８，９，１０より常にt2だけ
遅れたクロツクを受けることになる。 Therefore, flip-flop circuits 11 and 12 always receive a clock delayed by t 2 from flip-flop circuits 8, 9, and 10.
最初イニシヤル入力端INTにイニシヤルセツ
トパルスを入力すると、第３図に示すようにフリ
ツプフロツプ回路８がセツトされ、他は全てリセ
ツトされる。次にCKIより１番目のクロツクP1が
入力されると、フリツプフロツプ回路８の状態は
フリツプフロツプ回路９に移動し、以後クロツク
入力がP2、P3と入力される度に下段のフリツプ
フロツプ回路にＱ出力状態がシフトされて行く。
ところがフリツプフロツプ回路１１のクロツク端
CKに接続されている電極は液中に没しているた
め静電容量が多く、実際にフリツプフロツプ回路
１１のCK端に入力されるクロツクパルスはフリ
ツプフロツプ回路１０に入力されたものよりもt2
秒ほど遅れて入力されてくる。これがP2′であり、
P2′が入力されてくる時点ではすでにフリツプフ
ロツプ回路１０はＱ出力状態になつているためフ
リツプフロツプ回路１１のＤ端は高レベルであ
り、したがつてt2秒後にフリツプフロツプ回路１
１もＱ出力状態になつてしまう。このためクロツ
クパルスP2′入力後P3入力までのt3秒間、液面直
前と直後の２つのフリツプフロツプ回路が同時に
Ｑ出力状態となる。この状態を検出することによ
り液位を求めることができる。この検出はレベル
検出端LVEから行なつており、そのレベル検出
回路を第４図に基いて説明する。 When an initial set pulse is first input to the initial input terminal INT, the flip-flop circuit 8 is set as shown in FIG. 3, and everything else is reset. Next, when the first clock P 1 is input from CKI, the state of the flip-flop circuit 8 is transferred to the flip-flop circuit 9. From then on, each time the clock input is input as P 2 and P 3 , the state of the flip-flop circuit 8 is transferred to the lower flip-flop circuit. The output state is shifted.
However, the clock end of the flip-flop circuit 11
The electrode connected to CK has a large capacitance because it is submerged in the liquid, and the clock pulse actually input to the CK terminal of the flip-flop circuit 11 is t 2 higher than that input to the flip-flop circuit 10.
The input is delayed by about a second. This is P 2 ′,
At the time when P 2 ' is input, the flip-flop circuit 10 is already in the Q output state, so the D terminal of the flip-flop circuit 11 is at a high level. Therefore, after t 2 seconds, the flip-flop circuit 1
1 also ends up in the Q output state. Therefore, for t 3 seconds after the clock pulse P 2 ' is input and until the clock pulse P 3 is input, the two flip-flop circuits immediately before and immediately after the liquid level are simultaneously in the Q output state. By detecting this state, the liquid level can be determined. This detection is performed from the level detection terminal LVE, and the level detection circuit thereof will be explained based on FIG.
同図にはオペアンプを用いた加算回路を示して
あり、抵抗の値が全て等しいとみなすと、出力
V0は、
V0＝−（V1＋V2＋V3＋V4）
となり、V0端電位は複数電圧の加算の和となつ
ている。 The figure shows an adder circuit using an operational amplifier.If all resistance values are assumed to be equal, the output will be
For V 0 , V 0 =−(V 1 +V 2 +V 3 +V 4 ), and the potential at the V 0 end is the sum of multiple voltages.
通常フリツプフロツプ回路８〜１２は１個ずつ
Ｑ出力状態となるためV0の値も定まつたものと
なるが、水面付近の電極に接続された２つのフリ
ツプフロツプ回路が同時出力状態になるとV0出
力は変化するので、これを検出回路２６で検出す
る。 Normally, flip-flop circuits 8 to 12 enter the Q output state one by one, so the value of V 0 is also fixed, but if two flip-flop circuits connected to electrodes near the water surface enter the simultaneous output state, the V 0 output changes, so this is detected by the detection circuit 26.
電極間のピツチをＰ、イニシヤルセツト後検出
回路２６で同時出力状態が検知されるまでにフリ
ツプフロツプ回路に加えたクロツクパルス数を
ｎ、基準点P0から液面までの距離をＬとすると、
Ｌ＝nP
となるので、この演算を行なう回路を設けること
により液位を算出できる。 If the pitch between the electrodes is P, the number of clock pulses applied to the flip-flop circuit until the simultaneous output state is detected by the detection circuit 26 after initial setting is n, and the distance from the reference point P0 to the liquid level is L, then L = nP. Therefore, by providing a circuit that performs this calculation, the liquid level can be calculated.
次に計測値を遠方に伝送する手段を第５〜７図
によつて説明する。 Next, means for transmitting measured values to a distant place will be explained with reference to FIGS. 5 to 7.
第５図において、２７は水晶発振子等を用いた
クロツクパルス発生回路、２８は計測制御回路で
あり、クロツクパルスを入力して一定の時間割に
従つてパルスを発生する。発生するパルスは、
IT端からはイニシヤルセツトパルス、MK端
からはマークパルス、STA端からはスタートパ
ルスである。まず制御回路２８がIT端により
イニシヤルセツトパルスを出力するとフリツプフ
ロツプ回路群が初期化される。次にMK端より長
いマークパルスが出力され、同パルスはゲート２
９を通つて受信側Ｐに行き、同時にSTA端より
のパルスにより制御用フリツプフロツプ回路３１
がＱ出力状態となつてANDゲート３０より発振
器２７よりのクロツクパルスがCKIに出力され
る。このクロツクパルスは同時にデータパルスと
して受信側Ｐにも出力される。やがて検出回路２
６により水面が検出されると、STP端よりスト
ツプパルスが出力され、制御用フリツプフロツプ
回路３１が出力状態となり、クロツクパルスの
出力は停止する。一方受信側が受けとるパルスを
示したのが第６図で、１周期内にマークパルスと
データパルスがあり、これを受信側では第７図に
示すように、マーク信号検出後、データパルスの
数を計数し、スペース信号を検出した時点のパル
ス数にピツチＰを掛ければ液位が算出される。こ
れにより液位表示の更新を行ない、以後同じ操作
を行なうことで常に最新の液位を知ることができ
るようになつている。 In FIG. 5, 27 is a clock pulse generation circuit using a crystal oscillator or the like, and 28 is a measurement control circuit which inputs clock pulses and generates pulses according to a fixed time schedule. The generated pulse is
The initial set pulse is sent from the IT end, the mark pulse is sent from the MK end, and the start pulse is sent from the STA end. First, when the control circuit 28 outputs an initial set pulse from the IT terminal, the flip-flop circuit group is initialized. Next, a longer mark pulse is output from the MK end, and the same pulse is output from the gate 2.
9 to the receiving side P, and at the same time the control flip-flop circuit 31 is activated by the pulse from the STA terminal.
becomes the Q output state, and the clock pulse from the oscillator 27 is output from the AND gate 30 to CKI. This clock pulse is simultaneously output to the receiving side P as a data pulse. Eventually the detection circuit 2
When the water surface is detected by 6, a stop pulse is output from the STP terminal, the control flip-flop circuit 31 goes into the output state, and the output of the clock pulse is stopped. On the other hand, Fig. 6 shows the pulses received by the receiving side. There are mark pulses and data pulses within one cycle, and the receiving side calculates the number of data pulses after detecting the mark signal as shown in Fig. 7. The liquid level is calculated by counting and multiplying the number of pulses at the time the space signal is detected by the pitch P. This allows the liquid level display to be updated, and by performing the same operation thereafter, you can always know the latest liquid level.
以上のように本発明によれば、関単な回路によ
り正確な液位をデジタル値で検出することがで
き、クロツクパルスをデータパルスとして直接送
信することにより液位データを送信回路等で処理
する手間が省ける利点がある。 As described above, according to the present invention, an accurate liquid level can be detected as a digital value using a simple circuit, and by directly transmitting clock pulses as data pulses, it is possible to eliminate the need for processing liquid level data in a transmitting circuit, etc. This has the advantage that it can be omitted.
なお第８図は液位計測回路と電極群とを１個の
保護筒に設けず、分離して別々にした他の実施例
を示す。 Note that FIG. 8 shows another embodiment in which the liquid level measuring circuit and the electrode group are not provided in one protection tube, but are separated and provided separately.
また電極の構造は、第９図に示すように一様な
導体３５を内側に設けた円筒３４内に、電極板３
７を所要ピツチで表面に設けた筒３６を設けた構
造のものとするばあいもある。さらに第１０図に
示すように、導体３５はタンク側壁に設け、電極
板３７は、導体３５側タンク内側壁近くに立設し
たポスト３６へ所定ピツチで設けて導体３５と対
向させるようにするばあいもある。 Further, the structure of the electrode is as shown in FIG. 9, in which an electrode plate 3
In some cases, a structure is provided in which a tube 36 is provided on the surface of the tube 7 at a required pitch. Furthermore, as shown in FIG. 10, the conductor 35 is provided on the side wall of the tank, and the electrode plate 37 is provided at a predetermined pitch on a post 36 erected near the inner wall of the tank on the side of the conductor 35 so as to face the conductor 35. There is also love.
第１図は本発明に係る液位計測装置の一例を示
す回路図、第２図はクロツクパルス波形図、第３
図はクロツクパルスとフリツプフロツプ回路の出
力との関係を示す出力波形図、第４図はレベル検
出回路図、第５図は信号伝送回路図、第６図は送
信データの出力波形図、第７図は計測データを処
理する方法を示すフローチヤート、第８図は電極
と計測回路とを別々にしてタンクに取り付けた状
態を示す図、第９図と第１０図は電極構造の他の
実施例を示す図である。
図中、１……保護筒、２……電極収納管、２ａ
……液流入口、３，４，５，６，７……電極、
８，９，１０，１１，１２……フリツプフロツプ
回路、１３，１４，１５，１６，１７，２２，２
３，２４，２５……抵抗、１８，１９，２０，２
１……ダイオード、２６……検出回路、２７……
発振器、２８……制御回路、２９，３０……ゲー
ト回路、３１……制御用フリツプフロツプ回路、
３２……タンク、３３……液位計測回路。
FIG. 1 is a circuit diagram showing an example of a liquid level measuring device according to the present invention, FIG. 2 is a clock pulse waveform diagram, and FIG.
The figure is an output waveform diagram showing the relationship between clock pulses and the output of the flip-flop circuit, Figure 4 is a level detection circuit diagram, Figure 5 is a signal transmission circuit diagram, Figure 6 is an output waveform diagram of transmission data, and Figure 7 is a diagram of the signal transmission circuit. A flowchart showing a method for processing measurement data, Fig. 8 shows a state in which the electrode and measurement circuit are separated and attached to a tank, and Figs. 9 and 10 show other embodiments of the electrode structure. It is a diagram. In the figure, 1...protection tube, 2...electrode storage tube, 2a
...Liquid inlet, 3, 4, 5, 6, 7... Electrode,
8, 9, 10, 11, 12...Flip-flop circuit, 13, 14, 15, 16, 17, 22, 2
3, 24, 25...Resistance, 18, 19, 20, 2
1... Diode, 26... Detection circuit, 27...
Oscillator, 28...control circuit, 29, 30...gate circuit, 31...control flip-flop circuit,
32...Tank, 33...Liquid level measurement circuit.
Claims (1)
体と対峙するようタンク内に所定ピツチで垂直に
設けられた静電容量を有する複数の電極、これら
各電極に対応するシフトレジスタを構成するフリ
ツプフロツプ回路の各クロツク端とクロツクパル
スを出力するクロツク入力端に前記各電極を接続
し、各フリツプフロツプ回路の出力を検知する液
位計測回路、とを備えてなる液位計測装置。1 A conductor provided vertically within a tank, a plurality of electrodes having capacitance provided vertically within the tank at predetermined pitches to face the conductor, and a flip-flop configuring a shift register corresponding to each of these electrodes. A liquid level measuring device comprising: a liquid level measuring circuit that connects each of the electrodes to each clock terminal of the circuit and a clock input terminal that outputs a clock pulse, and detects the output of each flip-flop circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59069858A JPS60213822A (en) | 1984-04-07 | 1984-04-07 | Liquid-level measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59069858A JPS60213822A (en) | 1984-04-07 | 1984-04-07 | Liquid-level measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60213822A JPS60213822A (en) | 1985-10-26 |
| JPH0246885B2 true JPH0246885B2 (en) | 1990-10-17 |
Family
ID=13414922
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59069858A Granted JPS60213822A (en) | 1984-04-07 | 1984-04-07 | Liquid-level measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60213822A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007218740A (en) * | 2006-02-16 | 2007-08-30 | Taiheiyo Cement Corp | Liquid level sensor device, concrete product, and submergence state detection system |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5138880A (en) * | 1991-05-29 | 1992-08-18 | Lee/Maatuk Engineering, Inc. | Digital level sensing probe system |
| EP1744132A1 (en) * | 2005-07-11 | 2007-01-17 | Siemens Milltronics Process Instruments Inc. | Capacitive level sensor with a plurality of segments comprising each a capacitor and a circuit |
| CN105572479B (en) * | 2015-11-27 | 2018-11-02 | 天龙中闽科技有限公司 | The circuit module for measuring capacitance capacity of stackable extension, the convenient liquid level detection circuit of extension |
| US10926548B2 (en) * | 2016-04-29 | 2021-02-23 | Hewlett-Packard Development Company, L.P. | Printing apparatus and methods for detecting fluid levels |
-
1984
- 1984-04-07 JP JP59069858A patent/JPS60213822A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007218740A (en) * | 2006-02-16 | 2007-08-30 | Taiheiyo Cement Corp | Liquid level sensor device, concrete product, and submergence state detection system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60213822A (en) | 1985-10-26 |
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| EXPY | Cancellation because of completion of term |