JP2692687B2 - Concentration measuring device - Google Patents
Concentration measuring deviceInfo
- Publication number
- JP2692687B2 JP2692687B2 JP1234285A JP23428589A JP2692687B2 JP 2692687 B2 JP2692687 B2 JP 2692687B2 JP 1234285 A JP1234285 A JP 1234285A JP 23428589 A JP23428589 A JP 23428589A JP 2692687 B2 JP2692687 B2 JP 2692687B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- suspension
- light source
- amount
- level signal
- 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 - Fee Related
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- Investigating Or Analysing Materials By Optical Means (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、光を測定媒体とした濃度測定装置であっ
て、パルプ懸濁液におけるパルプ濃度の測定等、懸濁液
の濃度測定に用いられる濃度測定装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a concentration measuring device using light as a measurement medium, and is used for measuring the concentration of a pulp suspension, such as the measurement of pulp concentration in a pulp suspension. And a concentration measuring device.
一般に、紙は木材等から抽出された繊維（パルプ）に
よって製造され、そのパルプは水に懸濁されて用いられ
るので、そのパルプ懸濁液のパルプ濃度が生産される紙
の品質に大きく影響することが知られているが、このパ
ルプ濃度については、次のような問題点がある。Generally, paper is manufactured from fibers (pulp) extracted from wood or the like, and the pulp is used by being suspended in water. Therefore, the pulp concentration of the pulp suspension greatly affects the quality of the paper produced. However, this pulp concentration has the following problems.
（ａ） 複数のパルプを混合する場合において、混合す
べき各パルプ濃度が異なると、混合比率が異なり、所望
の性質を持つ紙が得られない。(A) In the case of mixing a plurality of pulp, if the concentration of each pulp to be mixed is different, the mixing ratio is different and paper having desired properties cannot be obtained.
（ｂ） 叩解を行う場合に、パルプ濃度を一定の値にし
ないと叩解されたパルプの性質が均一にならない。(B) When beaten, the properties of the beaten pulp are not uniform unless the pulp concentration is set to a constant value.
（ｃ） パルプ懸濁液に填料及び薬品を添加する場合、
パルプ濃度が異なると、パルプ濃度に対する填料や薬品
の比率が異なり、目標の性質が得られない。(C) When adding fillers and chemicals to the pulp suspension,
If the pulp concentration is different, the ratio of fillers and chemicals to the pulp concentration is different, and the desired properties cannot be obtained.
（ｄ） 原料調整後のパルプ懸濁液の濃度が異なってい
る場合、生産された紙の坪量が目標値と異なる。(D) When the concentration of the pulp suspension after adjusting the raw materials is different, the basis weight of the produced paper is different from the target value.
このように、パルプ濃度が異なると、生産された紙の
性質が変化し、品質に大きく影響を与えることから、製
紙にはパルプ濃度の制御が必要であり、そのために、パ
ルプ濃度の測定が不可欠である。As described above, when the pulp concentration is different, the properties of the produced paper change and greatly affect the quality. Therefore, it is necessary to control the pulp concentration in papermaking, and therefore, measurement of the pulp concentration is indispensable. It is.
ところで、パルプ濃度の測定には、光を媒体にした濃
度測定装置が用いられている。この濃度測定装置では、
懸濁液に光を照射し、懸濁液で反射、透過、散乱、吸
収、偏光を経て懸濁液から得られる反射光又は透過光等
の光を受光素子で受け、そのレベルによって懸濁液の濃
度測定を行う。Meanwhile, a pulp concentration is measured using a concentration measuring device using light as a medium. In this concentration measuring device,
The suspension is irradiated with light, and the suspension receives light such as reflected light or transmitted light obtained from the suspension through reflection, transmission, scattering, absorption, and polarization. Is measured.
この濃度測定装置においては、受光素子に対する入射
光に次のような情報、即ち、ノイズ成分が含まれてい
る。In this concentration measuring device, the following information, that is, a noise component is included in the light incident on the light receiving element.
i.光源及び受光素子と懸濁液とを遮断するための手段と
して、ウインドに設けられたガラス等の遮蔽手段におけ
る光の反射、散乱、吸収及び偏光によるノイズ成分（光
源側及び受光素子側で発生）。i. Noise components due to reflection, scattering, absorption and polarization of light in a shielding means such as glass provided in the window as means for shielding the light source and the light receiving element from the suspension (on the light source side and the light receiving element side Occurrence).
ii.光源又は受光素子が取り付けられている部分で光が
反射し、その光が懸濁液に入射するためのノイズ成分
（光源側及び受光素子側で発生）。ii. A noise component (generated on the light source side and the light receiving element side) that causes light to be reflected on the portion where the light source or the light receiving element is attached and the light is incident on the suspension.
これらのノイズ成分は測定精度に影響を与えている
が、さらに、受光素子で得られたレベル信号を処理する
電子回路においてもオフセットや、受光素子及び電子回
路の零点調整誤差等も測定精度に影響を与えている。Although these noise components affect the measurement accuracy, offsets in the electronic circuit that processes the level signal obtained by the light receiving element, and zero point adjustment errors of the light receiving element and the electronic circuit also affect the measurement accuracy. Is given.
また、濃度測定装置には、１つの受光素子を用いたも
の、２つの受光素子を設置して両者の比を求めるもの等
がある。前者の濃度測定装置では、ノイズ成分によって
懸濁液の実際の濃度より高い濃度を表すレベル信号が得
られ、しかも、ノイズ成分を電子回路側で相殺する場合
にはその温度変化による動作特性の変動や光源の照射光
量の変化が測定精度に影響を与える。後者の濃度測定装
置では、ノイズ成分によって低濃度領域における比の直
線性が悪化し、濃度を表すレベル信号におけるノイズ成
分の割合が大きくなるとともに、低濃度である場合には
測定誤差が大きくなり、しかも、光源の発光光量が変化
すると測定誤差が生じ、これを相殺することができな
い。In addition, there are a concentration measuring device using one light receiving element, a device using two light receiving devices, and obtaining a ratio between the two. In the former concentration measuring device, a level signal indicating a higher concentration than the actual concentration of the suspension is obtained by the noise component, and when the noise component is canceled by the electronic circuit side, the fluctuation of the operating characteristics due to the temperature change. And changes in the amount of light emitted by the light source affect the measurement accuracy. In the latter density measuring device, the linearity of the ratio in the low density region deteriorates due to the noise component, the ratio of the noise component in the level signal representing the density increases, and the measurement error increases when the density is low, In addition, a change in the amount of light emitted from the light source causes a measurement error, which cannot be offset.
このように、従来の濃度測定装置では、測定精度が低
く、安定性に欠け、再現性が低いため、パルプ懸濁液の
パルプ濃度を正確に測定することが困難であった。この
ため、原料調整工程において一定の品質のパルプを調整
し、抄紙工程において一定の品質の紙を抄くには、製紙
技術者の勘に頼ることが必要であり、極めて非能率的な
作業を余儀なくされていた。As described above, in the conventional concentration measuring device, the measurement accuracy is low, the stability is low, and the reproducibility is low. Therefore, it has been difficult to accurately measure the pulp concentration of the pulp suspension. For this reason, it is necessary to rely on the intuition of a papermaking engineer to adjust a certain quality of pulp in the raw material adjusting step and to make a certain quality of paper in the papermaking step, and it is extremely inefficient work. It had been.
そこで、この発明は、パルプ懸濁液等、任意の懸濁液
の懸濁物濃度の測定精度を高めるとともに、その測定の
安定性及び再現性を高めた濃度測定装置の提供を目的と
する。Accordingly, an object of the present invention is to provide a concentration measuring device that increases the measurement accuracy of the concentration of a suspended substance in an arbitrary suspension such as a pulp suspension, and also increases the stability and reproducibility of the measurement.
この発明の濃度測定装置は、任意の液体と懸濁物とか
らなる懸濁液（２）に光を照射する光源（発光素子8A）
と、この光源と同一の駆動源により発光し、前記光源と
同等の発光光量を発する参照用光源（発光素子8B）と、
前記光源により前記懸濁液に照射される照射光量とし
て、前記参照用光源側の発光光量を検出する光量検出手
段（受光素子20）と、前記光源からの光照射に基づいて
前記懸濁液側からの光を受け、前記懸濁液の懸濁物濃度
を表すレベル信号を発生する受光手段（受光素子10、1
2）と、この受光手段が出力する前記レベル信号のレベ
ルを前記光量検出手段の検出出力に応じて補正する補正
手段（補正回路28、30）とを備えて、前記光源側の発光
光量によって生じる前記レベル信号のレベル変化分を前
記参照用光源の発光光量の変化分で相殺させたことを特
徴とする。The concentration measuring device of the present invention is a light source (light emitting element 8A) for irradiating a suspension (2) consisting of an arbitrary liquid and a suspension with light.
And a reference light source (light emitting element 8B) that emits light from the same drive source as this light source and emits the same amount of light as the light source,
As the amount of light emitted to the suspension by the light source, a light amount detecting means (light receiving element 20) for detecting the amount of light emitted from the reference light source side, and the suspension side based on light irradiation from the light source. The light receiving means (light receiving elements 10, 1) for receiving the light from the
2) and correction means (correction circuits 28, 30) for correcting the level of the level signal output by the light receiving means in accordance with the detection output of the light amount detection means, and are generated by the light emission amount on the light source side. The change in the level of the level signal is offset by the change in the amount of light emitted from the reference light source.
また、この発明の濃度測定装置は、任意の液体と懸濁
物とからなる懸濁液（２）に光を照射する光源（発光素
子8A）と、この光源と同一の駆動源により発光し、前記
光源と同等の発光光量を発する参照用光源（発光素子8
B）と、前記光源からの光照射に基づいて前記懸濁液側
からの光を受け、前記懸濁液の懸濁物濃度を表す第１の
レベル信号を発生する第１の受光手段（受光素子10）
と、この第１の受光手段とともに設けられて、前記光源
からの光照射に基づいて前記懸濁液側からの光を受け、
前記懸濁液の懸濁物濃度を表す第２のレベル信号を発生
する第２の受光手段（受光素子12）と、前記光源により
前記懸濁液に照射される照射光量として、前記参照用光
源側の発光光量を検出する光量検出手段（受光素子20）
と、この光量検出手段の検出出力により前記第１のレベ
ル信号のレベルを補正する第１の補正手段（補正回路2
8）と、前記光量検出手段の検出出力により前記第２の
レベル信号のレベルを補正する第２の補正手段（補正回
路30）と、前記第１の補正手段により補正された前記第
１のレベル信号と、前記第２の補正手段により補正され
た前記第２のレベル信号との比により前記懸濁液の懸濁
物濃度を算出する演算手段（演算装置32）とを備えて、
前記光源側の発光光量によって生じる前記第１及び第２
のレベル信号のレベル変化分を前記参照用光源の発光光
量の変化分で相殺させたことを特徴とする。Further, the concentration measuring device of the present invention emits light from a light source (light emitting element 8A) that irradiates a suspension (2) composed of an arbitrary liquid and a suspension with light, and the same drive source as this light source, A reference light source (light emitting element 8) that emits the same amount of emitted light as the light source.
B) and a first light receiving means (light receiving means) for receiving light from the suspension side based on light irradiation from the light source and generating a first level signal representing a suspension concentration of the suspension. Element 10)
And, provided with this first light receiving means, receives light from the suspension side based on light irradiation from the light source,
A second light receiving means (light receiving element 12) for generating a second level signal representing the suspension concentration of the suspension, and the reference light source as the irradiation light amount applied to the suspension by the light source. Light amount detecting means (light receiving element 20) for detecting the amount of light emitted from the side
And a first correction means (correction circuit 2 for correcting the level of the first level signal by the detection output of the light amount detection means.
8), second correction means (correction circuit 30) for correcting the level of the second level signal by the detection output of the light amount detection means, and the first level corrected by the first correction means. A calculation means (calculation device 32) for calculating a suspension concentration of the suspension based on a ratio of the signal and the second level signal corrected by the second correction means,
The first and second generated by the amount of light emitted from the light source side
The level change amount of the level signal of 1 is offset by the change amount of the emitted light amount of the reference light source.
濃度を測定すべき懸濁液に光源から光を照射すると、
懸濁液に入射した光は懸濁液中で反射、散乱、吸収、偏
光等を経て懸濁液から出る。この場合、入射された光は
懸濁液中の懸濁物によって反射され、受光手段に受光さ
れる。したがって、受光手段には、その懸濁液から得ら
れた光のレベル即ち、懸濁液の懸濁物濃度を表すレベル
信号が得られる。When light is applied to the suspension whose concentration is to be measured from a light source,
Light incident on the suspension exits the suspension via reflection, scattering, absorption, polarization, and the like in the suspension. In this case, the incident light is reflected by the suspended matter in the suspension and received by the light receiving means. Therefore, the light receiving means obtains a level signal representing the level of light obtained from the suspension, that is, the concentration of the suspended substance in the suspension.
そして、前記光源から前記懸濁液に対する照射光量を
検出し、その照射光量に応じてレベル信号のレベルを補
正すると、ノイズ成分が相殺され、測定精度が高められ
る。Then, by detecting the irradiation light amount of the suspension from the light source and correcting the level of the level signal according to the irradiation light amount, the noise component is canceled and the measurement accuracy is improved.
また、この濃度測定装置では、請求項２に記載の通
り、第１及び第２の受光手段によって懸濁液から得られ
た反射光又は透過光等の光が受光され、個別に前記懸濁
物の濃度を表す第１及び第２のレベル信号を得るととも
に、前記光源から前記懸濁液に対する照射光量に応じて
各レベル信号のレベル補正が行われる。Further, in this concentration measuring device, as described in claim 2, light such as reflected light or transmitted light obtained from the suspension is received by the first and second light receiving means, and the suspended matter is individually received. The first and second level signals representing the concentration are obtained, and the level of each level signal is corrected according to the amount of light emitted from the light source to the suspension.
また、補正された各レベル信号の比から濃度を算出す
るので、光源の発光光量の変化等の影響やノイズ成分が
相殺された精度の高い演算出力が得られる。Further, since the density is calculated from the ratio of the corrected level signals, it is possible to obtain a highly accurate calculation output in which the influence of a change in the amount of light emitted from the light source and the noise component are canceled out.
そして、この濃度測定装置は、前記光源と同一の駆動
源によって駆動される参照用光源を設置して、光源と同
一条件で点灯する参照用光源からの受光光量を参照光量
としてレベル補正を行うことにより、光源側の発光光量
によって生じる前記レベル信号のレベル変化分を前記参
照用光源の発光光量の変化分で相殺したので、精度の高
い濃度検出を実現している。In this density measuring device, a reference light source driven by the same driving source as the light source is installed, and level correction is performed using the received light amount from the reference light source that is turned on under the same conditions as the light source as the reference light amount. As a result, the level change amount of the level signal caused by the light emission amount on the light source side is offset by the change amount of the emission light amount of the reference light source, so that highly accurate density detection is realized.
以下、この発明を図面に示した実施例を参照して詳細
に説明する。Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
第１図は、この発明の濃度測定装置の一実施例を示
す。FIG. 1 shows an embodiment of the concentration measuring apparatus of the present invention.
濃度を測定すべき懸濁液２には、水等の液体にパルプ
等の懸濁物として光を透過しないか或いは光を反射する
微細な固形物を懸濁したものが用いられる。この懸濁液
２が通流する通路４の一部、例えば、製紙では原料調整
工程又は抄紙工程等の原料移送路に濃度測定部６が設置
されている。As the suspension 2 whose concentration is to be measured, a suspension in which a fine solid that does not transmit light or reflects light as a suspension such as pulp in a liquid such as water is used. A concentration measuring unit 6 is installed in a part of a passage 4 through which the suspension 2 flows, for example, a raw material transfer passage in a raw material adjusting step or a papermaking step in papermaking.
この濃度測定部６には、懸濁液２を遮断する遮蔽手段
として遮蔽ガラス60が設置され、この遮蔽ガラス60を通
して懸濁液２に光Liを照射する光源として発光素子8Aが
設置されているとともに、懸濁液２で反射、屈折、偏
光、散乱等を経て懸濁液２から到来する光Lrを受ける第
１及び第２の受光手段として受光素子10、12が設置され
ている。発光素子8Aには参照用光源としての発光素子8B
が直列に接続され、各発光素子8A、8Bは共通の駆動源と
しての駆動回路14によって駆動される。This concentration measuring unit 6, is shielding glass 60 is provided as shielding means for blocking the suspension 2, the suspension 2 through the shielding glass 60 is the light emitting element 8A is installed as a light source for irradiating light L i together we are, reflected by a suspension 2, refraction, polarization, light-receiving elements 10 and 12 is provided as the first and second light receiving means receiving light L r coming from the suspension 2 via the scattering or the like. The light-emitting element 8A has a light-emitting element 8B as a reference light source.
Are connected in series, and each of the light emitting elements 8A and 8B is driven by a drive circuit 14 as a common drive source.
濃度測定部６には、第２図の（Ａ）に示すように、発
光素子8A及び受光素子10、12を取り付ける円柱状を成す
取付部61とともにその前面部を覆う円板状の絞り板62が
設けられている。取付部61には、直径方向に特定の間隔
を置いて変位した位置に取付孔63、64、65が形成されて
いる。取付孔64は、前面側を小径し、中途部に段部を設
けて径大にされており、受光面積の大なる受光素子10が
取り付けられるようになっている。また、絞り板62には
取付孔63に取り付けられた発光素子8Aの発光部を臨ませ
る透孔66Aが形成されているとともに、受光素子10、12
に対する受光光量を絞る絞孔66B、66Cが形成されてい
る。したがって、濃度測定部６には、第２図の（Ｂ）に
示すように、取付部61に発光素子8A及び受光素子10、12
が取り付けられており、この実施例では、受光素子10は
受光素子12より僅かに後方に変位した位置に取り付けら
れている。そして、取付部61及び絞り板62は、固定孔6
7、68にねじを挿入して図示しない測定部本体側に一体
的に固定され、図示していない防護ケース内に収容され
る。As shown in FIG. 2A, the concentration measuring section 6 has a cylindrical mounting section 61 for mounting the light emitting element 8A and the light receiving elements 10 and 12, and a disk-shaped diaphragm plate 62 for covering the front surface thereof. Is provided. Mounting holes 63, 64, and 65 are formed in the mounting portion 61 at positions displaced at specific intervals in the diameter direction. The mounting hole 64 has a small diameter on the front surface side and is provided with a step portion in the middle to have a large diameter, so that the light receiving element 10 having a large light receiving area can be mounted. Further, the aperture plate 62 is formed with a through hole 66A which faces the light emitting portion of the light emitting element 8A attached to the attaching hole 63, and the light receiving elements 10 and 12 are formed.
Aperture holes 66B and 66C for reducing the amount of received light are formed. Therefore, as shown in FIG. 2 (B), the light emitting element 8A and the light receiving elements 10, 12 are attached to the attaching section 61.
Are mounted, and in this embodiment, the light receiving element 10 is mounted at a position slightly rearward of the light receiving element 12. Then, the mounting portion 61 and the diaphragm plate 62 have the fixing holes 6
Screws are inserted into 7, 68 to be integrally fixed to the measuring section main body side (not shown) and housed in a protective case (not shown).
そして、懸濁液２から得られる光Lrは受光素子10、12
でそれぞれ受光され、受光素子10の受光出力は第１の濃
度測定回路を成す信号検出回路16、受光素子12の受光集
力は第２の濃度測定回路を成す信号検出回路18に加えら
れ、受光素子10、12の各出力に応じて濃度を表す第１及
び第２のレベル信号V1、V2が得られる。Then, the light L r obtained from the suspension 2 light receiving elements 10 and 12
The light-receiving output of the light-receiving element 10 is applied to the signal detecting circuit 16 which constitutes the first concentration measuring circuit, and the light-collecting power of the light-receiving element 12 is applied to the signal detecting circuit 18 which constitutes the second concentration measuring circuit. First and second level signals V 1 and V 2 representing the densities are obtained according to the respective outputs of the elements 10 and 12.
また、発光素子8B側には、光量検出手段として受光素
子20が設置され、受光素子20には発光素子8Aの発光光
量、即ち、懸濁液２に対する照射光量が発光素子8Bを通
じて間接的に検出される。即ち、この受光素子20の出力
が参照用測定回路としての信号検出回路22に加えられ、
信号検出回路22には照射光量を表すレベル信号V3が得ら
れ、第１及び第２の補正信号形成回路24、26に加えられ
ている。各補正信号形成回路24、26ではレベル信号V3に
応じた補正信号V31、32が形成され、補正信号V31はレベ
ル信号V1を補正する第１の補正手段として設置された補
正回路28に加えられ、また、補正信号V32はレベル信号V
2を補正する第２の補正手段として設置された補正回路3
0に加えられている。In addition, a light receiving element 20 is provided on the light emitting element 8B side as a light amount detecting means, and the light emitting amount of the light emitting element 8A, that is, the irradiation light amount to the suspension 2 is indirectly detected through the light emitting element 8B. Is done. That is, the output of the light receiving element 20 is added to the signal detection circuit 22 as a reference measurement circuit,
The signal detection circuit 22 obtains a level signal V 3 representing the irradiation light amount and is applied to the first and second correction signal forming circuits 24 and 26. Correction signal V 31 corresponding to the level signal V 3 in each correction signal forming circuits 24 and 26, 32 are formed, the correction signal V 31 level signal V 1 first established as correction means a correction circuit 28 for correcting the And the correction signal V 32 is a level signal V
2 second established as correction means the correction circuit 3 corrects the
Added to 0.
補正回路28では、レベル信号V1が補正信号V31によっ
て補正され、その補正出力としてレベル信号V10が得ら
れ、また、補正回路30では、レベル信号V2が補正信号V
32によって補正され、その補正出力としてレベル信号V
20が得られる。In the correction circuit 28, the level signal V 1 is corrected by the correction signal V 31, the level signal V 10 is obtained as the correction output, also, in the correction circuit 30, the level signal V 2 is the correction signal V
32 , and the level signal V
20 is obtained.
そして、補正回路28、30から得られたレベル信号
V10、V20は、濃度を算出する演算装置32に加えられる。
演算装置32は、アナログ演算手段又はディジタル演算手
段によって構成され、各レベル信号V10、V20の比（V20/
V10）によって濃度が算出され、出力端子34から濃度出
力電圧V0が得られる。Then, the level signals obtained from the correction circuits 28 and 30
V 10 and V 20 are applied to an arithmetic unit 32 for calculating the density.
The arithmetic unit 32 is constituted by analog arithmetic means or digital arithmetic means, and has a ratio (V 20 / V 20 / V 20) between the level signals V 10 and V 20.
V 10 ), the density is calculated, and a density output voltage V 0 is obtained from the output terminal 34.
以上の構成とすれば、懸濁液２に発光素子8Aから光Li
が照射されると、受光素子10、12には反射、屈折、散
乱、偏光等を経て懸濁液２から得られる光Lrが受光さ
れ、信号検出回路16、18には懸濁液２の懸濁物濃度を表
すレベル信号V1、V2が得られる。If the above configuration, the light L i from the light emitting element 8A in suspension 2
When light is emitted, the light receiving elements 10 and 12 receive the light L r obtained from the suspension 2 through reflection, refraction, scattering, polarization, etc., and the signal detection circuits 16 and 18 receive the suspension 2 from the suspension 2. Level signals V 1 and V 2 representing the suspension concentration are obtained.
そして、発光素子8Aと共通の駆動回路14によって駆動
される発光素子8Bを通じて発光素子8Aの発光光量、即
ち、懸濁液２に対する照射光量が間接的に受光素子20に
検出され、信号検出回路22にはその照射光量を表すレベ
ル信号V3が得られる。補正信号形成回路24、26には、レ
ベル信号V3に対応して補正信号V31、V32が形成され、補
正回路28、30に加えられる。そして、信号検出回路16、
18で得られたレベル信号V1、V2は、補正信号V31、V32に
よって個別に補正され、レベル信号V10、V20に変換され
る。したがって、演算装置32では、レベル信号V10、V20
の比が求められ、濃度を表す濃度出力電圧V0が得られ
る。The amount of light emitted from the light emitting element 8A, that is, the amount of light applied to the suspension 2 is indirectly detected by the light receiving element 20 through the light emitting element 8B driven by the common driving circuit 14 with the light emitting element 8A. the level signal V 3 representing the irradiation light amount is obtained. The correction signal forming circuit 24 and 26, the correction signal V 31, V 32 corresponding to the level signal V 3 is formed, it is added to the correction circuit 28, 30. And the signal detection circuit 16,
The level signals V 1 and V 2 obtained at 18 are individually corrected by the correction signals V 31 and V 32 , and are converted into level signals V 10 and V 20 . Therefore, in the arithmetic unit 32, the level signals V 10 , V 20
Is obtained, and the concentration output voltage V 0 representing the concentration is obtained.
次に、第３図の（Ａ）は、この発明の濃度測定装置に
おける発光素子8A、8Bの駆動回路14の具体的な回路構成
例を示し、第３図の（Ｂ）はスイッチング駆動のための
スイッチングパルス発生手段を示す。Next, FIG. 3 (A) shows a concrete circuit configuration example of the drive circuit 14 for the light emitting elements 8A, 8B in the concentration measuring device of the present invention, and FIG. 3 (B) is for switching drive. The switching pulse generating means of is shown.
駆動回路14には、発光ダイオードで構成された発光素
子8A、8Bに駆動電流IDを流す駆動トランジスタ140が設
置され、この駆動トランジスタ140のコレクタには電源
電圧Vccが加えられ、また、そのエミッタと接地との間
には減流抵抗142を介して発光素子8B、8Aが直列に接続
されている。駆動トランジスタ140のベースには、光量
調整部36からの光量調整電圧Vcが抵抗144を介して加え
られているとともに、そのベース入力を断続的に遮断し
て駆動トランジスタ140をスイッチングさせるスイッチ
ング回路146が接続されている。スイッチング回路146
は、半導体スイッチ回路等で構成され、スイッチングパ
ルス発生手段としてのスイッチングパルス発生部38から
加えられる第５図のＡに示すスイッチングパルスφ１の
低（Ｌ）レベル区間で導通状態、その高（Ｈ）レベル区
間で非導通状態になり、周期的なスイッチング動作を繰
り返す。The drive circuit 14 is provided with a drive transistor 140 for supplying a drive current I D to the light emitting elements 8A and 8B formed of light emitting diodes, and the power supply voltage V cc is applied to the collector of the drive transistor 140. The light emitting elements 8B and 8A are connected in series via the current reduction resistor 142 between the emitter and the ground. A light amount adjustment voltage V c from the light amount adjusting unit 36 is applied to the base of the drive transistor 140 via a resistor 144, and a switching circuit 146 that switches the drive transistor 140 by intermittently interrupting its base input. Are connected. Switching circuit 146
Is composed of a semiconductor switch circuit or the like, and is in a conductive state in the low (L) level section of the switching pulse φ 1 shown in A of FIG. ) It becomes non-conductive in the level section and repeats the periodic switching operation.
そして、光量調整部36には、電源電圧Vccを分圧して
光量調整電圧Vcを形成する可変抵抗360が設置され、可
変抵抗360によって得られた光量調整電圧Vcがバッファ
回路362を通じて出力される。Then, the light amount adjusting unit 36 is a variable resistor 360 is installed to the power supply voltage V cc divides to form a light amount adjustment voltage V c, the light quantity adjustment voltage V c obtained by the variable resistor 360 is outputted through the buffer circuit 362 To be done.
このような構成とすれば、駆動トランジスタ140に
は、ベースに光量調整部36から光量調整電圧Vcが加えら
れて導通条件が成立し、スイッチング回路146のスイッ
チング動作により、第５図のＤに示すように、断続的な
駆動電流IDが得られる。そこで、発光素子8A、8Bは、断
続的な駆動電流IDのＨレベル区間で点灯、そのＬレベル
区間で消灯する。したがって、発光素子8Aから出た光Li
が懸濁液２に照射され、また、発光素子8Bから出た光Li
が受光素子20に入力される。With such a configuration, the light quantity adjusting voltage V c is applied to the base of the drive transistor 140 from the light quantity adjusting unit 36 to establish the conduction condition, and the switching operation of the switching circuit 146 causes the drive transistor 140 to move to D in FIG. As shown, an intermittent drive current I D is obtained. Therefore, the light emitting elements 8A and 8B are turned on in the H level section of the intermittent drive current ID and turned off in the L level section. Therefore, the light L i emitted from the light emitting element 8A
Is radiated to the suspension 2 and the light L i emitted from the light emitting element 8B is emitted.
Is input to the light receiving element 20.
次に、第４図は、第１図に示した信号検出回路16、1
8、22、補正回路28、30及び補正信号形成回路24、26の
具体的な回路構成例を示す。Next, FIG. 4 shows the signal detection circuits 16 and 1 shown in FIG.
8 and 22, specific circuit configuration examples of the correction circuits 28 and 30 and the correction signal forming circuits 24 and 26 will be described.
懸濁液２から得られた光Lrは、受光ダイオードで構成
された受光素子10、12に受光され、そのレベルに応じた
受光電流Ir1、Ir2が流れる。また、発光素子8Bに対応し
た受光素子20にはその光Liが受光され、そのレベルに応
じた受光電流Iiが流れる。受光電流Ir1は信号検出回路1
6、受光電流Ir2は信号検出回路18、また、受光電流Iiは
信号検出回路22に加えられる。Light L r obtained from the suspension 2 is received by the light receiving element 10, 12 made of a light receiving diode, light-receiving current I r1, I r2 flows corresponding to the level. Further, the light receiving element 20 corresponding to the light emitting element 8B the light L i is received, receiving current I i flows corresponding to the level. The received light current Ir1 is the signal detection circuit 1.
6, the light-receiving current I r2 is the signal detecting circuit 18, also receiving the current I i is applied to the signal detection circuit 22.
受光電流Ir1が加えられると、信号検出回路16の受光
電流入力部に設置された電流・電圧変換回路（I/V）160
で電圧に変換された後、増幅器162で増幅され、帯域通
過フィルタ164で不要な周波数成分が除かれて、第６図
のＪに示す出力が得られる。そして、抵抗165及びキャ
パシタ166からなるフィルタ167に加えられて不要な直流
成分が除かれ、第６図のＫに示す出力が得られ、この出
力がスイッチング回路168を経て第６図のＭに示すレベ
ル信号V1に変換される。スイッチング回路168は、半導
体スイッチ回路等で構成され、スイッチングパルス発生
部38から加えられる第５図のＡ及びＢに示すスイッチン
グパルスφ１、φ２により、第５図のＣに示す周期的な
スイッチング動作を繰り返す。即ち、スイッチングパル
スφ１の区間ｔφのＨレベル区間で等価的な接点ａ側が
導通状態、その他の区間で接点ａ側が非導通ないし接点
ｂ側が導通状態となり、発光素子8A、8Bの点灯間隔に同
期した導通区間を以て周期的なスイッチング動作を繰り
返す。この場合、スイッチング回路168は、各スイッチ
ングパルスφ１、φ２が共にＨレベルになる区間で接点
ａ、ｂの何れにも導通しない中間状態を呈し、第５図の
ＣのＦに示すように、ON、OFFの中間であるフローティ
ング状態となる。したがって、スイッチング回路168で
は、等価的な接点ａ側の導通区間によって第６図のＭに
示すレベル信号V1が得られる。このレベル信号V1の間に
存在するレベルＦは、スイッチング回路168の接点が中
間に位置するためのフローティングレベルを表す。When the light receiving current Ir1 is applied, the current / voltage conversion circuit (I / V) 160 installed at the light receiving current input section of the signal detection circuit 16
After being converted into a voltage, the signal is amplified by the amplifier 162, and unnecessary frequency components are removed by the band-pass filter 164, thereby obtaining an output shown by J in FIG. Then, an unnecessary DC component is removed by being added to a filter 167 including a resistor 165 and a capacitor 166, and an output shown in FIG. 6K is obtained. This output passes through a switching circuit 168 and is shown in M in FIG. It is converted into the level signal V 1. The switching circuit 168 is composed of a semiconductor switch circuit or the like, and performs periodic switching shown in FIG. 5C by switching pulses φ 1 and φ 2 shown in FIGS. 5A and 5B applied from the switching pulse generator 38. Repeat the operation. That is, the equivalent contact a side is conductive in the H level section of the section tφ of the switching pulse φ 1 , and the contact a side is non-conductive or the contact b side is conductive in the other sections, and is synchronized with the lighting interval of the light emitting elements 8A and 8B. The periodic switching operation is repeated with the conducted section. In this case, the switching circuit 168 exhibits an intermediate state in which neither of the contact points a and b conducts in a section where both the switching pulses φ 1 and φ 2 are at the H level, as shown in F of FIG. 5C. , ON, and OFF. Therefore, the switching circuit 168, the level signal V 1 shown in M of Figure 6 by the equivalent contacts a side of the conductive section is obtained. Level F existing between the level of the signal V 1 was represents a floating level for contact of the switching circuit 168 is located in the middle.
また、受光電流Ir2が信号検出回路18に加えられる
と、同様に、電流・電圧変換回路180で電圧に変換され
た後、増幅器182で増幅され、帯域通過フィルタ184で不
要な周波数成分が除かれて第７図のＯに示す出力が得ら
れる。そして、抵抗185及びキャパシタ186からなるフィ
ルタ187に加えられて不要な直流成分が除かれ、第７図
のＰに示す出力が得られ、この出力がスイッチング回路
188を経て第７図のＱに示すレベル信号V2に変換され
る。スイッチング回路188は、スイッチング回路168と同
様に第５図のＡ及びＢに示すスイッチングパルスφ１、
φ２により、第５図のＣに示す周期的なスイッチング動
作を繰り返す。即ち、スイッチングパルスφ１の区間ｔ
φにおけるＨレベル区間で等価的な接点ａ側が導通状
態、その他の区間で接点ａ側が非導通ないし接点ｂ側が
導通状態となるとともに、各スイッチングパルスφ１、
φ２が共にＨレベルとなる区間でフローティング状態Ｆ
となる周期的なスイッチング動作を繰り返す。したがっ
て、スイッチング回路188では、等価的な接点ａ側の導
通区間によって第７図のＱに示すレベル信号V2が得られ
る。このレベル信号V2の間に存在するレベルＦは、スイ
ッチング回路188の接点が中間に位置するためのフロー
ティングレベルを表す。When the received light current I r2 is applied to the signal detection circuit 18, it is similarly converted into a voltage by the current / voltage conversion circuit 180, then amplified by the amplifier 182, and an unnecessary frequency component is removed by the band pass filter 184. The output shown in O of FIG. 7 is obtained. Then, an unnecessary DC component is removed by being added to the filter 187 including the resistor 185 and the capacitor 186, and an output shown by P in FIG. 7 is obtained, and this output is a switching circuit.
It is converted to a level signal V 2 shown by Q in FIG. 7 via 188. The switching circuit 188 is similar to the switching circuit 168 in that the switching pulse φ 1 shown in A and B of FIG.
The phi 2, repeated periodic switching operation shown in C of FIG. 5. That is, the switching pulse φ 1 of the interval t
In the H level section of φ, the equivalent contact a side becomes conductive, and in the other sections the contact a side becomes non-conductive or the contact b side becomes conductive, and each switching pulse φ 1 ,
Floating state F in the section where φ 2 is both at H level
Is repeated. Therefore, in the switching circuit 188, the level signal V 2 shown by Q in FIG. 7 is obtained by the equivalent conduction section on the contact a side. Level F existing between the level signal V 2 represents the floating level for contact of the switching circuit 188 is located in the middle.
そして、受光電流Iiは、信号検出回路22における電流
・電圧変換回路220、増幅器222、帯域通過フィルタ22
4、抵抗225及びキャパシタ226からなるフィルタ227並び
にスイッチング回路228を経て、第５図のＥに示すレベ
ル信号V3に変換される。スイッチング回路228は、スイ
ッチング回路168と同様に第５図のＡ及びＢに示すスイ
ッチングパルスφ１、φ２により、第５図のＣに示す周
期的なスイッチング動作を繰り返し、スイッチング回路
228には、等価的な接点ａ側の導通区間によって第５図
のＥに示すレベル信号V3が得られる。このレベル信号V3
の間に存在するレベルＦは、スイッチング回路228の接
点が中間に位置するためのフローティングレベルを表
す。そして、このレベル信号V3は、バッファ回路40を経
て補正信号形成回路24、26に加えられている。The light-receiving current Ii is supplied to the current / voltage conversion circuit 220, the amplifier 222, and the bandpass filter 22 in the signal detection circuit 22.
4, resistor 225 and through the filter 227 and switching circuit 228 consisting of a capacitor 226, is converted into level signal V 3 shown in E of FIG. 5. The switching circuit 228 repeats the periodic switching operation shown in FIG. 5C by the switching pulses φ 1 and φ 2 shown in FIGS.
228, the level signal V 3 shown in E of FIG. 5 by the equivalent contacts a side of the conductive section is obtained. This level signal V 3
The level F existing in between represents the floating level for the contact of the switching circuit 228 to be located in the middle. Then, the level signal V 3 is applied to the correction signal forming circuits 24 and 26 via a buffer circuit 40.
補正信号形成回路24にはゲイン調整手段として増幅器
240が設置され、増幅器240の逆相入力端子（−）側に抵
抗241を介してレベル信号V3が加えられ、また、増幅器2
40の逆相入力端子（−）と出力端子との間にゲイン調整
用の可変抵抗242が接続されている。この増幅器240の後
段部にはオフセット調整手段として増幅器243が設置さ
れ、増幅器240の出力が抵抗244を介して逆相入力端子
（−）に加えられている。また、オフセットレベル設定
手段として可変抵抗245が設置され、この可変抵抗245で
得られた電圧が抵抗246を介して逆相入力端子（−）に
加えられているとともに、抵抗247を介して出力端子側
に加えられている。したがって、この補正信号形成回路
24では、増幅器240側で可変抵抗242で設定されたレベル
によってゲイン調整が施された後、増幅器243側で適当
なオフセット調整が行われて、第５図のＦに示す補正信
号V31が形成される。The correction signal forming circuit 24 includes an amplifier as a gain adjusting means.
240, a level signal V 3 is applied to the negative-phase input terminal (−) side of the amplifier 240 via the resistor 241, and the amplifier 240
A variable resistor 242 for gain adjustment is connected between the 40 negative-phase input terminals (−) and the output terminals. An amplifier 243 is provided as a means for adjusting the offset at the subsequent stage of the amplifier 240, and the output of the amplifier 240 is applied to the negative-phase input terminal (-) via the resistor 244. A variable resistor 245 is provided as an offset level setting means. The voltage obtained by the variable resistor 245 is applied to a negative-phase input terminal (−) via a resistor 246, and the output terminal is connected via a resistor 247. Has been added to the side. Therefore, this correction signal forming circuit
In 24, after the gain has been adjusted by the set level by the variable resistor 242 by an amplifier 240 side, is made appropriate offset adjustment amplifier 243 side, the correction signal V 31 shown in F of FIG. 5 is formed Is done.
一方、補正信号形成回路26には、補正信号形成回路24
と同様に、ゲイン調整手段として増幅器260が設置さ
れ、増幅器260の逆相入力端子（−）側に抵抗261を介し
てレベル信号V3が加えられ、また、増幅器260の逆相入
力端子（−）と出力端子との間にゲイン調整用の可変抵
抗262が接続されている。この増幅器260の後段部にはオ
フセット調整手段として増幅器263が設置され、増幅器2
60の出力が抵抗264を介して逆相入力端子（−）に加え
られている。また、オフセットレベル設定手段として可
変抵抗265が設置され、この可変抵抗265で得られた電圧
が抵抗266を介して逆相入力端子（−）に加えられてい
るとともに、抵抗267を介して出力端子側に加えられて
いる。したがって、この補正信号形成回路26では、増幅
器260側で可変抵抗262で設定されたレベルによってゲイ
ン調整が施された後、増幅器263側で適当なオフセット
調整が行われて、第５図のＧに示す補正信号V32が形成
される。On the other hand, the correction signal forming circuit 26 includes a correction signal forming circuit 24.
Similarly to the above, an amplifier 260 is provided as a gain adjusting means, a level signal V 3 is applied to the negative-phase input terminal (−) side of the amplifier 260 via a resistor 261, and the negative-phase input terminal (− ) And an output terminal, a variable resistor 262 for gain adjustment is connected. An amplifier 263 is provided at the subsequent stage of the amplifier 260 as an offset adjusting means.
The output of 60 is applied to the negative phase input terminal (-) via the resistor 264. Further, a variable resistor 265 is provided as an offset level setting means, and a voltage obtained by the variable resistor 265 is applied to a negative-phase input terminal (−) via the resistor 266, and an output terminal is provided via the resistor 267. Has been added to the side. Therefore, in the correction signal forming circuit 26, after the gain adjustment is performed on the amplifier 260 side by the level set by the variable resistor 262, an appropriate offset adjustment is performed on the amplifier 263 side, and G in FIG. The indicated correction signal V 32 is formed.
そして、補正回路28には減算器280が設置され、その
後段に第５図のＡ及びＢに示すスイッチングパルス
φ１、φ２により、第５図のＣに示す周期的なスイッチ
ング動作を繰り返すスイッチング回路282が設置されて
いる。したがって、減算器280では、レベル信号V1から
補正信号V31が減算され、第６図のＮに示すように、補
正されたレベル信号V1′がスイッチング回路282を通じ
て取り出される。Then, a subtractor 280 is provided in the correction circuit 28, and the switching circuit that repeats the periodic switching operation shown in FIG. 5C by the switching pulses φ 1 and φ 2 shown in FIGS. A circuit 282 is provided. Therefore, in the subtractor 280, the correction signal V 31 is subtracted from the level signal V 1, and the corrected level signal V 1 ′ is taken out through the switching circuit 282 as shown by N in FIG.
また、補正回路30には減算器300が設置され、その後
段に第５図のＡ及びＢに示すスイッチングパルスφ１、
φ２により、第５図のＣに示す周期的なスイッチング動
作を繰り返すスイッチング回路302が設置されている。
したがって、減算器300では、レベル信号V2から補正信
号V32が減算され、第７図のＳに示すように、補正され
たレベル信号V2′がスイッチング回路302を通じて取り
出される。Further, a subtractor 300 is provided in the correction circuit 30, and a switching pulse φ 1 shown in FIGS.
The phi 2, the switching circuit 302 to repeat periodic switching operation shown in C of FIG. 5 is installed.
Therefore, in the subtractor 300, the correction signal V 32 is subtracted from the level signal V 2, and the corrected level signal V 2 ′ is taken out through the switching circuit 302 as shown by S in FIG.
各補正回路28、30の後段には応答時間を調整する手段
として応答時間調整回路42、44が設置され、応答時間調
整回路42は可変抵抗420及びキャパシタ422からなる積分
回路、同様に、応答時間調整回路44は可変抵抗440及び
キャパシタ442からなる積分回路で構成されている。し
たがって、レベル信号V1′は応答時間調整回路42及びそ
の後段に設置されたバッファ回路46を経てレベル信号V
10として出力端子50から取り出され、また、レベル信号
V2′は応答時間調整回路44及びその後段に設置されたバ
ッファ回路48を経てレベル信号V20として出力端子52か
ら取り出される。各レベル信号V10、V20は第１図に示し
ている演算装置32に加えられ、各レベル信号V10、V20の
比から、第７図のＴに示すように、濃度出力電圧V0が得
られる。Response time adjusting circuits 42 and 44 are provided at the subsequent stage of each of the correction circuits 28 and 30 as means for adjusting the response time, and the response time adjusting circuit 42 is an integration circuit including a variable resistor 420 and a capacitor 422. The adjustment circuit 44 is configured by an integration circuit including a variable resistor 440 and a capacitor 442. Therefore, the level signal V 1 ′ passes through the response time adjusting circuit 42 and the buffer
It is taken out from the output terminal 50 as 10 and the level signal
V 2 ′ is extracted from an output terminal 52 as a level signal V 20 via a response time adjusting circuit 44 and a buffer circuit 48 provided at a subsequent stage. The respective level signals V 10 and V 20 are applied to the arithmetic unit 32 shown in FIG. 1, and the concentration output voltage V 0 is given from the ratio of the respective level signals V 10 and V 20 as shown in T of FIG. Is obtained.
次に、第８図及び第９図は、この発明の濃度測定装置
の他の実施例を示す。Next, FIGS. 8 and 9 show another embodiment of the concentration measuring apparatus of the present invention.
前記実施例では、発光素子8Aと受光素子10、12とを近
接位置に設置し、発光素子8Aから出た光Liを懸濁液２に
入射し、懸濁液２から得られた光Lrを各受光素子10、12
で受光し、両者の比から濃度を測定するようにしたが、
第８図に示すように、通路４に跨がって発光素子8Aと受
光素子10、12とを対向させて配置し、発光素子8Aから出
た光Liの中、懸濁液２から得られた光としての透過光Lt
を受光素子10、12で受光し、両者の比からパルプ濃度を
測定するようにしてもよい。パルプは光を反射して透過
しないので、透過光Ltはパルプ等の懸濁物によって減衰
するので、前記実施例と同様にパルプ濃度を測定するこ
とができる。In the above-described embodiment, the light emitting element 8A and the light receiving elements 10 and 12 are installed in close proximity to each other, the light L i emitted from the light emitting element 8A is incident on the suspension 2, and the light L obtained from the suspension 2 is generated. r for each light-receiving element 10, 12
The light was received at and the concentration was measured from the ratio of the two.
As shown in FIG. 8, the light-emitting element 8A and the light-receiving elements 10 and 12 are arranged so as to face each other across the passage 4 and are obtained from the suspension 2 in the light L i emitted from the light-emitting element 8A. Transmitted light as reflected light L t
Alternatively, the light receiving elements 10 and 12 may receive the light, and the pulp concentration may be measured from the ratio of the two. Since the pulp reflects light and does not transmit, the transmitted light Lt is attenuated by a suspended material such as pulp, so that the pulp concentration can be measured in the same manner as in the above embodiment.
また、前記実施例では発光素子8Aに直列に発光素子8B
を接続し、懸濁液２に対する照射光量を発光素子8Bを通
じて検出したが、第９図に示すように、発光素子8Aに対
して受光素子20を設置して発光素子8Aから照射光量を直
接検出するようにしてもよい。In the above embodiment, the light emitting element 8B is connected in series with the light emitting element 8A.
The amount of irradiation light for the suspension 2 was detected through the light emitting element 8B, and as shown in FIG. 9, the light receiving element 20 was installed to the light emitting element 8A to directly detect the irradiation light amount from the light emitting element 8A. You may do it.
なお、実施例では、懸濁液の濃度測定としてパルプ懸
濁液を例に取って説明したが、この発明は、光を透過可
能な液体中に光を透過しない懸濁物が懸濁された懸濁液
における懸濁物濃度の測定に用いることができ、パルプ
濃度の測定に限定されるものではない。In the examples, the pulp suspension was described as an example for measuring the concentration of the suspension, but in the present invention, a suspension that does not transmit light is suspended in a liquid capable of transmitting light. It can be used to measure the suspension concentration in a suspension and is not limited to measuring pulp concentration.
実験は第１図に示した濃度測定装置を用いて行い、比
較のために１つの光源に対して２つの受光素子を設置し
た濃度計を用いた。The experiment was performed using the density measuring device shown in FIG. 1, and for comparison, a densitometer having two light receiving elements provided for one light source was used for comparison.
第10図は、従来の濃度計による出力特性曲線を示す。
この特性では、パルプ懸濁液濃度が約１％以下の領域で
濃度出力電圧V0が極端に上昇しており、低濃度領域では
ノイズ成分の割合が真の懸濁液濃度を表す信号成分に対
して大きくなり、低濃度に移行する程、測定精度が低下
していることを表している。FIG. 10 shows an output characteristic curve of a conventional densitometer.
In this characteristic, the concentration output voltage V 0 is extremely increased in a region where the pulp suspension concentration is about 1% or less, and in a low concentration region, the ratio of the noise component is a signal component representing the true suspension concentration. On the other hand, it shows that the measurement accuracy decreases as the concentration becomes larger and shifts to a lower concentration.
次に、第11図は、この発明にかかる濃度測定装置の出
力特性曲線を示す。この特性では、パルプ懸濁液濃度が
約１％以下の領域においても、従来のような濃度出力電
圧V0の極端な上昇はなく、直線性が改善されていること
が分かる。Next, FIG. 11 shows an output characteristic curve of the concentration measuring device according to the present invention. This property, also in the pulp suspension concentration of about 1% or less of the region, rather than an extreme increase in the conventional concentration output voltage V 0 as, it can be seen that the linearity is improved.
次に、第12図は、従来の濃度計による光源の発光効率
が変化した場合の出力特性曲線を示し、特性ａは発光効
率が100％、特性ｂは発光効率が90％、特性ｃは発光効
率が80％である。このように、発光効率の低下に応じて
濃度出力電圧V0が上昇するのは、ノイズ成分の割合が真
の懸濁液濃度を表す信号成分に対して大きくなるためで
ある。この場合、光源の発光効率の変化とは別に光源に
対する受光素子の設置位置や、光源又は受光素子を保持
している構造によっても、濃度出力電圧V0が変化する。Next, FIG. 12 shows an output characteristic curve when the luminous efficiency of the light source by the conventional densitometer is changed. The characteristic a has a luminous efficiency of 100%, the characteristic b has a luminous efficiency of 90%, and the characteristic c has a luminous efficiency. The efficiency is 80%. Thus, the concentration output voltage V 0 increases with a decrease in luminous efficiency is the ratio of the noise component is large relative to the signal component representing the true suspension density. In this case, the change in the light emission efficiency of the light source separate from the installation position and the light receiving element with respect to the light source, by the structure that holds the light source or light receiving element, a change in density the output voltage V 0.
次に、第13図は、この発明にかかる濃度測定装置によ
る光源の発光効率が変化した場合の実験結果を示す。発
光効率が減少しても、この発明にかかる濃度測定装置で
は、出力特性に変化はなく、安定した濃度出力電圧V0が
得られている。Next, FIG. 13 shows an experimental result when the luminous efficiency of the light source by the concentration measuring device according to the present invention is changed. Even the luminous efficiency is decreased, in a concentration measuring apparatus according to the invention, no change in the output characteristics, stable density output voltage V 0 is obtained.
以上説明したように、この発明によれば、次のような
効果が得られる。As described above, according to the present invention, the following effects can be obtained.
（ａ） 光源から懸濁液に対する照射光量を検出し、そ
の照射光量に応じてレベル信号のレベルを補正すると、
光源の発光光量の変化等の影響やノイズ成分が相殺され
るので、パルプ懸濁液等、任意の懸濁液における懸濁物
濃度の測定精度を高めることができるとともに、その測
定の安定性及び再現性を高めることができる。(A) When the amount of irradiation light on the suspension is detected from the light source and the level of the level signal is corrected according to the amount of irradiation light,
Since the influence of the change in the amount of light emitted from the light source and the noise component are canceled out, it is possible to improve the accuracy of measurement of the concentration of suspended matter in an arbitrary suspension such as a pulp suspension, and the stability and stability of the measurement. The reproducibility can be improved.
（ｂ） 補正された各レベル信号の比から濃度を算出す
るので、光源の発光光量の変化等の影響やノイズ成分が
相殺された精度の高い演算出力を得ることができる。(B) Since the density is calculated from the corrected ratio of each level signal, it is possible to obtain a highly accurate calculation output in which the influence of a change in the amount of light emitted from the light source and the noise component are canceled.
（ｃ） 同一の駆動源によって駆動される参照用光源を
設置したので、光源と同一条件で点灯する参照用光源に
よって容易に照射光量を検出でき、測定精度を向上させ
ることができる。(C) Since the reference light source driven by the same drive source is installed, the irradiation light amount can be easily detected by the reference light source that is turned on under the same conditions as the light source, and the measurement accuracy can be improved.
第１図はこの発明の濃度測定装置の一実施例を示すブロ
ック図、 第２図は第１図に示した濃度測定装置における濃度測定
部の具体的な構成例を示す図、 第３図は第１図に示した濃度置測定装置における発光素
子の駆動回路の具体的な回路構成例とともにスイッチン
グパルス発生手段を示す回路図、 第４図は第１図に示した濃度測定装置における信号検出
回路、補正回路及び補正信号形成回路の具体的な回路構
成例を示す回路図、 第５図ないし第７図は第３図及び第４図に示した濃度測
定装置の動作を示す図、 第８図及び第９図はこの発明の濃度測定装置の他の実施
例を示す図、 第10図ないし第13図はこの発明及び従来の濃度測定装置
の実験結果を示す図である。 ２……懸濁液 8A……発光素子（光源） 8B……発光素子（参照用光源） 10……受光素子（第１の受光手段） 12……受光素子（第２の受光手段） 14……駆動回路（駆動源） 16、18、22……信号検出回路 20……受光素子（光量検出手段） 28……補正回路（第１の補正手段） 30……補正回路（第２の補正手段） 32……演算装置（演算手段）FIG. 1 is a block diagram showing an embodiment of the concentration measuring apparatus of the present invention, FIG. 2 is a diagram showing a concrete configuration example of a concentration measuring unit in the concentration measuring apparatus shown in FIG. 1, and FIG. FIG. 1 is a circuit diagram showing a switching pulse generating means together with a concrete circuit configuration example of a drive circuit of a light emitting element in the concentration measuring device shown in FIG. 1, and FIG. 4 is a signal detecting circuit in the concentration measuring device shown in FIG. FIG. 8 is a circuit diagram showing a concrete circuit configuration example of a correction circuit and a correction signal forming circuit, FIGS. 5 to 7 are diagrams showing the operation of the concentration measuring apparatus shown in FIGS. 3 and 4, and FIG. And FIG. 9 is a diagram showing another embodiment of the concentration measuring device of the present invention, and FIGS. 10 to 13 are diagrams showing experimental results of the concentration measuring device of the present invention and the conventional one. 2 ... Suspension 8A ... Light emitting element (light source) 8B ... Light emitting element (reference light source) 10 ... Light receiving element (first light receiving means) 12 ... Light receiving element (second light receiving means) 14 ... ... Drive circuit (drive source) 16, 18, 22 ... Signal detection circuit 20 ... Light receiving element (light amount detection means) 28 ... Correction circuit (first correction means) 30 ... Correction circuit (second correction means) ) 32 …… Computing device (computing means)
───────────────────────────────────────────────────── フロントページの続き (72)発明者 青柳 靖 静岡県富士市西柏原新田201番地 ▲高 ▼木産業株式会社内 (56)参考文献 特開 昭50−160088（ＪＰ，Ａ) 特開 昭62−123555（ＪＰ，Ａ) 特開 昭56−51646（ＪＰ，Ａ) 特開 昭59−210347（ＪＰ，Ａ) 特開 昭56−54338（ＪＰ，Ａ) 特開 昭60−154142（ＪＰ，Ａ) ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasushi Yasushi 201 Nishi-Kashiwara Nitta, Fuji City, Shizuoka Prefecture ▲ High ▼ Inside Wood Industry Co., Ltd. (56) References JP 50-500088 (JP, A) JP JP-A-62-123555 (JP, A) JP-A-56-51646 (JP, A) JP-A-59-210347 (JP, A) JP-A-56-54338 (JP, A) JP-A-60-154142 (JP, A) , A)
Claims (2)
を照射する光源と、 この光源と同一の駆動源により発光し、前記光源と同等
の発光光量を発する参照用光源と、 前記光源により前記懸濁液に照射される照射光量とし
て、前記参照用光源側の発光光量を検出する光量検出手
段と、 前記光源からの光照射に基づいて前記懸濁液側からの光
を受け、前記懸濁液の懸濁物濃度を表すレベル信号を発
生する受光手段と、 この受光手段が出力する前記レベル信号のレベルを前記
光量検出手段の検出出力に応じて補正する補正手段と、 を備えて、前記光源側の発光光量によって生じる前記レ
ベル信号のレベル変化分を前記参照用光源の発光光量の
変化分で相殺させたことを特徴とする濃度測定装置。1. A light source for irradiating a suspension of an arbitrary liquid and a suspension with light, and a reference light source for emitting light by the same driving source as the light source and emitting the same amount of emitted light as the light source. As the irradiation light amount irradiated to the suspension by the light source, a light amount detection unit that detects the amount of light emitted from the reference light source side, and light from the suspension side based on light irradiation from the light source. Light receiving means for receiving and generating a level signal representing the concentration of suspended solids in the suspension, and correcting means for correcting the level of the level signal output by the light receiving means according to the detection output of the light amount detecting means, The density measuring device, comprising: a change amount of the level signal of the level signal caused by the amount of emitted light from the light source side, which is offset by a change amount of the emitted light amount of the reference light source.
を照射する光源と、 この光源と同一の駆動源により発光し、前記光源と同等
の発光光量を発する参照用光源と、 前記光源からの光照射に基づいて前記懸濁液側からの光
を受け、前記懸濁液の懸濁物濃度を表す第１のレベル信
号を発生する第１の受光手段と、 この第１の受光手段とともに設けられて、前記光源から
の光照射に基づいて前記懸濁液側からの光を受け、前記
懸濁液の懸濁物濃度を表す第２のレベル信号を発生する
第２の受光手段と、 前記光源により前記懸濁液に照射される照射光量とし
て、前記参照用光源側の発光光量を検出する光量検出手
段と、 この光量検出手段の検出出力により前記第１のレベル信
号のレベルを補正する第１の補正手段と、 前記光量検出手段の検出出力により前記第２のレベル信
号のレベルを補正する第２の補正手段と、 前記第１の補正手段により補正された前記第１のレベル
信号と、前記第２の補正手段により補正された前記第２
のレベル信号との比により前記懸濁液の懸濁物濃度を算
出する演算手段と、 を備えて、前記光源側の発光光量によって生じる前記第
１及び第２のレベル信号のレベル変化分を前記参照用光
源の発光光量の変化分で相殺させたことを特徴とする濃
度測定装置。2. A light source for irradiating light on a suspension composed of an arbitrary liquid and a suspension, and a reference light source for emitting light by the same driving source as the light source and emitting the same amount of emitted light as the light source. First light receiving means for receiving light from the suspension side based on light irradiation from the light source to generate a first level signal representing a suspension concentration of the suspension; A second level signal, which is provided together with the light receiving means, receives the light from the suspension side based on the light irradiation from the light source, and generates a second level signal indicating the concentration of suspended matter in the suspension. A light receiving means, a light amount detecting means for detecting an emitted light amount on the side of the reference light source as an irradiation light amount applied to the suspension by the light source, and a detection output of the light amount detecting means for detecting the first level signal. First correction means for correcting the level, and detection by the light amount detection means Second correction means for correcting the level of the second level signal by force, the first level signal corrected by the first correction means, and the first level signal corrected by the second correction means. Two
Calculating means for calculating the concentration of the suspension in the suspension based on the ratio to the level signal of the above-mentioned level signal, and the level change of the first and second level signals caused by the amount of light emitted from the light source side. A concentration measuring device characterized in that it is offset by a change in the emitted light amount of a reference light source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1234285A JP2692687B2 (en) | 1989-09-08 | 1989-09-08 | Concentration measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1234285A JP2692687B2 (en) | 1989-09-08 | 1989-09-08 | Concentration measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0396834A JPH0396834A (en) | 1991-04-22 |
| JP2692687B2 true JP2692687B2 (en) | 1997-12-17 |
Family
ID=16968584
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1234285A Expired - Fee Related JP2692687B2 (en) | 1989-09-08 | 1989-09-08 | Concentration measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2692687B2 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50160088A (en) * | 1974-06-17 | 1975-12-25 | ||
| JPS5651646A (en) * | 1979-10-02 | 1981-05-09 | Ricoh Co Ltd | Toner concentration sensor |
| JPS5654338A (en) * | 1979-10-11 | 1981-05-14 | Horiba Ltd | Simple checker of gas analyzer |
| JPS59210347A (en) * | 1983-05-16 | 1984-11-29 | Nohmi Bosai Kogyo Co Ltd | Function testing machine of scattered light type smoke detector |
| JPS60154142A (en) * | 1984-01-24 | 1985-08-13 | Matsushita Electric Works Ltd | Photoelectric smoke sensor |
-
1989
- 1989-09-08 JP JP1234285A patent/JP2692687B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0396834A (en) | 1991-04-22 |
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