JP2002365238A - Moisture measuring sensor and apparatus - Google Patents
Moisture measuring sensor and apparatusInfo
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- JP2002365238A JP2002365238A JP2001172849A JP2001172849A JP2002365238A JP 2002365238 A JP2002365238 A JP 2002365238A JP 2001172849 A JP2001172849 A JP 2001172849A JP 2001172849 A JP2001172849 A JP 2001172849A JP 2002365238 A JP2002365238 A JP 2002365238A
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- measured
- moisture content
- resistance
- electromagnetic field
- measuring
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、共振器から発生す
る電磁界を被測定物に浸透させ、そのときの電磁界吸収
から水分量を測定する水分量測定装置に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring the amount of water based on the absorption of an electromagnetic field caused by an electromagnetic field generated from a resonator penetrating an object to be measured.
【０００２】[0002]
【従来の技術】例えば、フレッシュコンクリートに含ま
れる水分量の測定は、電子レンジを用いた高周波加熱乾
燥法により、乾燥前後の重量変化から計算式で単位水量
を求めている。この方法は、乾燥に時間がかかること
と、本来フレッシュコンクリートに含まれている粗骨材
である砂利を取り除いたモルタルを計測しているため、
砂利を除去したときの砂利に付着した水分が誤差とな
る。また、ラジオ・アイソトープを応用した水分センサ
が開発されているが、取り扱いに注意が必要なのと装置
の価格が高価であることが問題である。2. Description of the Related Art For example, the amount of water contained in fresh concrete is measured by a high-frequency heating and drying method using a microwave oven, and the unit water amount is calculated from a change in weight before and after drying. This method measures the time required for drying and the mortar from which gravel, which is the coarse aggregate originally contained in fresh concrete, is removed.
Water attached to the gravel when the gravel is removed causes an error. Further, a moisture sensor using a radioisotope has been developed. However, there are problems in that care must be taken in handling and the price of the device is high.
【０００３】特に、コンクリート構造物の強度は、コン
クリート中のセメントに対する水の量で調整されてい
る。しかし、コンクリートの強度は、フレッシュコンク
リートの状態ではわかりにくく測定が困難であった。フ
レッシュコンクリートの水分測定が簡便にできれば、コ
ンクリート品質の向上に役立つ。[0003] In particular, the strength of a concrete structure is adjusted by the amount of water relative to the cement in the concrete. However, the strength of the concrete was difficult to understand in the state of fresh concrete and was difficult to measure. A simple measurement of the moisture content of fresh concrete will help improve concrete quality.
【０００４】[0004]
【発明が解決しようとする課題】フレッシュコンクリー
ト等の水分量を検出する手法として、電磁波（マイクロ
波）を照射・透過させその減衰により水分量をもとめる
ものもあるが、照射・透過させたマイクロ波の減衰と出
力が必ずしも比例しないので、測定精度が良くなかっ
た。As a method of detecting the amount of moisture in fresh concrete or the like, there is a method of irradiating and transmitting electromagnetic waves (microwaves) to determine the amount of water by attenuating the electromagnetic waves (microwaves). The measurement accuracy was not good because the attenuation and output were not always proportional.
【０００５】そこで、本発明は被測定物の水分量を瞬時
にかつ正確に測定する水分量測定センサ及び水分量測定
装置を提供することを目的とする。Accordingly, an object of the present invention is to provide a moisture content measuring sensor and a moisture content measuring device for instantaneously and accurately measuring the moisture content of an object to be measured.
【０００６】[0006]
【課題を解決するための手段】請求項１に記載の水分量
測定センサは、電磁界を被測定物に浸透させ、そのとき
の電磁界吸収から水分量を測定する電磁波を使用した水
分量測定技術において、被測定物における電磁界損失に
対して直線的に比例した出力特性を生じる検出用負荷を
有していることを特徴とする。ここで「電磁波」にはマ
イクロ波が含まれる。また、「検出負荷」には検出用ダ
イオードの他、抵抗やコンデンサが含まれる。また「被
測定物における電磁界損失に対して直線的に比例した出
力特性」を得るには、例えば、検出器において検出用負
荷として検出用ダイオードを使用し、検出用ダイオード
の電流−抵抗値の特性を考慮して、回路電流の大きいと
ころで生じる飽和傾向と、回路電流の小さいところで生
じる飽和傾向を組み合わせて、被測定物の検出水分量と
検出出力が直線的に比例するように、検出用ダイオード
のダイオードインピーダンスを選択すると良い。According to a first aspect of the present invention, there is provided a moisture content measuring sensor for measuring a moisture content using an electromagnetic wave for infiltrating an electromagnetic field into an object to be measured and measuring the moisture content from the electromagnetic field absorption at that time. The technology is characterized by having a detection load that produces an output characteristic that is linearly proportional to the electromagnetic field loss in the device under test. Here, “electromagnetic waves” include microwaves. The “detection load” includes a resistor and a capacitor in addition to the detection diode. In order to obtain “output characteristics that are linearly proportional to the electromagnetic field loss in the device under test”, for example, a detector diode is used as a detector load in the detector, and the current-resistance value of the detector diode is used. Taking into account the characteristics, the saturation tendency that occurs when the circuit current is large and the saturation tendency that occurs when the circuit current is small are combined, and the detection diode is set so that the detected moisture content of the DUT and the detection output are linearly proportional. It is good to select the diode impedance of.
【０００７】この水分量測定センサは、被測定物に発信
部から電磁波を発信して、被測定物に浸透した電磁波を
受信することにより被測定物に含まれる水分量を測るこ
とができるから、瞬時に水分量を測ることができる。ま
た、被測定物に含まれる水分量による電磁界損失に対し
て直線的に比例した電気的出力を生じさせることができ
るので、被測定物に含まれる水分量を良好な精度で測定
することができる。[0007] This moisture content measurement sensor can measure the moisture content contained in the measured object by transmitting an electromagnetic wave from the transmitting unit to the measured object and receiving the electromagnetic wave permeating the measured object. Instantly measure the amount of water. In addition, since an electrical output can be generated that is linearly proportional to the electromagnetic field loss due to the amount of moisture contained in the DUT, the amount of moisture contained in the DUT can be measured with good accuracy. it can.
【０００８】請求項２に記載の水分量測定センサは、被
測定物に電磁波を発信する発信部と、前記被測定物に浸
透した電磁波を受信する受信部とを備え、電磁界を被測
定物に浸透させ、そのときの電磁界吸収から水分量を測
定する電磁波を使用した水分量測定技術において、図２
に示すように、前記発信部での抵抗を示す第１の抵抗
（３２）、被測定物の共振による損失を示す第２の抵抗
（３３）、コイル（３４）及びコンデンサ(３５)、受信
部の検出用負荷での抵抗を示す第３の抵抗（３６）を直
列に繋いで水分量測定センサの等価回路を表した場合
に、第３の抵抗（３６）の抵抗値が第１の抵抗（３２）
及び第２の抵抗（３３）の各抵抗値の合計の少なくとも
１/10以上であって、被測定物における電磁界損失に対
して直線的に比例した出力特性を生じることを特徴とす
る。この水分量測定センサは、受信部の検出用負荷にお
いて出力値が大きくなるので検出精度が良くなる。According to a second aspect of the present invention, there is provided a moisture content measuring sensor comprising: a transmitting section for transmitting an electromagnetic wave to an object to be measured; and a receiving section for receiving the electromagnetic wave permeating the object to be measured. In water content measurement technology using electromagnetic waves for measuring water content from electromagnetic field absorption at that time, FIG.
As shown in (1), a first resistor (32) indicating a resistance in the transmitting unit, a second resistor (33) indicating a loss due to resonance of the device under test, a coil (34) and a capacitor (35), a receiving unit When the third resistor (36) indicating the resistance at the detection load is connected in series to represent an equivalent circuit of the moisture content measurement sensor, the resistance value of the third resistor (36) is changed to the first resistance ( 32)
And at least 1/10 or more of the sum of the respective resistance values of the second resistor (33), and produces an output characteristic that is linearly proportional to the electromagnetic field loss in the device under test. Since the output value of the moisture content measurement sensor increases at the detection load of the receiving unit, the detection accuracy is improved.
【０００９】請求項３に記載の水分量測定装置は、被測
定物を収容する測定容器と、前記測定容器の外面に沿っ
て移動可能に取り付けた請求項１に記載の水分量測定セ
ンサと、前記水分量測定センサと測定容器とを相対移動
させる移動機構と、前記水分量測定センサで測定された
被測定物の水分量のデータを出力する出力手段とを備
え、前記水分量測定センサと測定容器とを相対移動させ
て複数箇所で被測定物に電磁界を浸透させて被測定物に
含まれる水分量を測定し、被測定物の平均的な水分量を
検出することを特徴とする。ここで、「出力手段」は、
データの記録や、表示、プリントができる手段をいうも
のとする。[0010] According to a third aspect of the present invention, there is provided a moisture content measuring device, comprising: a measuring container accommodating an object to be measured; a moisture content measuring sensor according to the first aspect, movably mounted along an outer surface of the measuring container; A movement mechanism for relatively moving the water content measurement sensor and the measurement container; and output means for outputting data on the water content of the measured object measured by the water content measurement sensor. The method is characterized in that the container and the container are relatively moved to permeate an electromagnetic field into the object at a plurality of locations to measure the amount of water contained in the object, and to detect the average amount of water in the object. Here, "output means"
It means a means that can record, display, and print data.
【００１０】請求項４に記載の水分量測定装置は、被測
定物がフレッシュコンクリート又は砂のいずれかである
ことを特徴とする。被測定物が砂である場合は、例え
ば、砂を貯めるホッパーを測定容器とし、測定容器とし
てのホッパーの側面に水分量測定センサを移動可能に取
り付け、ホッパーに対して複数箇所で砂の水分量が測定
できるようにしても良い。The moisture content measuring device according to claim 4 is characterized in that the object to be measured is either fresh concrete or sand. When the object to be measured is sand, for example, a hopper for storing sand is used as a measurement container, and a water content measurement sensor is movably mounted on the side of the hopper as the measurement container, and the water content of the sand is measured at a plurality of positions with respect to the hopper. May be measured.
【００１１】[0011]
【発明の実施の形態】以下、本発明の一実施形態に係る
水分量測定装置を図面に基づいて説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a water content measuring device according to an embodiment of the present invention will be described with reference to the drawings.
【００１２】この水分量測定装置は、図１に示す水分量
測定センサ20を備えている。水分量測定センサ20は、セ
ラミックス基板に蒸着されたマイクロストリップ共振器
アンテナ21と、センサ部としての発信回路基板22と、Ｃ
ＰＵコントロール基板23とで構成され、堅牢なステンレ
ス製のケース24に組み込み、マイクロストリップ共振器
アンテナ21が配設された測定面に保護セラミックス25を
装着したものである。This water content measuring device includes a water content measuring sensor 20 shown in FIG. The moisture content measurement sensor 20 includes a microstrip resonator antenna 21 deposited on a ceramic substrate, a transmission circuit board 22 as a sensor unit,
It is constructed by a PU control board 23, is incorporated in a robust stainless steel case 24, and has a protective ceramic 25 mounted on a measurement surface on which the microstrip resonator antenna 21 is disposed.
【００１３】マイクロストリップ共振器アンテナ21は、
電磁界を被測定物に浸透させる発信部としての機能と、
被測定物に浸透した電磁界を受信する受信部としての機
能を備えている。The microstrip resonator antenna 21 includes:
A function as a transmitting unit that allows the electromagnetic field to penetrate the DUT,
It has a function as a receiving unit that receives the electromagnetic field that has penetrated the device under test.
【００１４】保護セラミックス25は、被測定物との磨耗
を防止し、かつ、マイクロストリップ共振器アンテナ21
から発生する電磁界を安定させるためのものである。保
護セラミックス25には、防水効果を高めるため、水浸入
防止Ｏリング26とコーティング剤で強化されている。水
分量測定センサ20は、ＣＰＵコントロール基板23からの
周波数指令信号に伴い発信回路基板22から、指定の周波
数の電磁波が出力される。この出力はマイクロストリッ
プ共振器アンテナ21に接続され、このマイクロストリッ
プ共振器アンテナ21から発生する電磁波を被測定物に浸
透させる。また、被測定物に浸透した電磁波をマイクロ
ストリップ共振器アンテナ21で受信して発信回路基板22
内に取り付けた検出用負荷としての検出用ダイオードに
より、被測定物の検出水分量に直線的に比例した検出出
力が得られるようになっている。The protective ceramics 25 prevents wear on the object to be measured, and protects the microstrip resonator antenna 21 from wear.
To stabilize the electromagnetic field generated from the The protective ceramic 25 is reinforced with a water intrusion prevention O-ring 26 and a coating agent to enhance the waterproof effect. The water content measurement sensor 20 outputs an electromagnetic wave having a specified frequency from the transmission circuit board 22 in accordance with the frequency command signal from the CPU control board 23. This output is connected to a microstrip resonator antenna 21, and an electromagnetic wave generated from the microstrip resonator antenna 21 penetrates the device under test. The microstrip resonator antenna 21 receives the electromagnetic wave that has penetrated the DUT and transmits it to the transmission circuit board 22.
A detection diode linearly proportional to the detected moisture content of the object to be measured can be obtained by a detection diode as a detection load mounted inside.
【００１５】この水分量測定センサ20は、図２に示すよ
うに、発信器、共振器（被測定物の損失）および検出器
を等価回路で表して説明することができる。この等価回
路は、２ポート共振器の一方のポートに発信器を、他方
のポートに検出器を接続したものである。図２中、31は
アンテナ電力源、32は発信部での抵抗としての発信回路
の内部インピーダンス（第1の抵抗）、33は被測定物の
共振による損失（電磁界吸収）としての共振器損失抵抗
（第2の抵抗）、34は共振器誘導器、35は共振器容量
器、36は受信部の検出用ダイオードの抵抗としての検出
用ダイオードのインピーダンス（第3の抵抗）をそれぞ
れ示している。As shown in FIG. 2, the water content measurement sensor 20 can be described by expressing an oscillator, a resonator (loss of an object to be measured) and a detector by an equivalent circuit. This equivalent circuit has a transmitter connected to one port of a two-port resonator and a detector connected to the other port. In FIG. 2, 31 is an antenna power source, 32 is an internal impedance (first resistance) of a transmitting circuit as a resistance in a transmitting section, and 33 is a resonator loss as a loss due to resonance of the DUT (electromagnetic field absorption). A resistance (second resistance), 34 indicates a resonator inductor, 35 indicates a resonator capacitor, and 36 indicates an impedance (third resistance) of a detection diode as a resistance of the detection diode of the receiving unit. .
【００１６】また、共振器損失抵抗33は、共振器を形成
している導体や誘電体によるものと、外に漏れた電磁界
が被測定物で受けるもの（Rm）との２種類に分けて取扱
うこととする。また、発信器ポート１による回路の良好
度QをQ1ext、負荷ポート２をQ2ext、損失のうちの共振
器を形成している導体や誘電体によるものをQ0、外に漏
れた電磁界が被測定物によるものをQmとする。The resonator loss resistor 33 is divided into two types, one consisting of a conductor or a dielectric forming the resonator, and the other (R m ) of the electromagnetic field leaked to the outside under the object to be measured. Will be handled. Also, the circuit quality Q by the transmitter port 1 is Q 1ext , the load port 2 is Q 2ext , the loss of the conductor or dielectric forming the resonator is Q 0 , and the electromagnetic field leaked out There are those from the object to be measured and Q m.
【００１７】発信器から負荷への共振周波数における透
過電力は式１に示す。The transmitted power at the resonance frequency from the transmitter to the load is shown in Equation 1.
【００１８】[0018]
【数1】 で与えられる。(Equation 1) Given by
【００１９】また、式１中の回路全体の良好度Ｑtは式
２の関係で表される。Further, goodness Q t of the entire circuit in Formula 1 is represented by the relationship of Equation 2.
【数２】 (Equation 2)
【００２０】また、式１中のＸは式３の関係で表され
る。Further, X in Equation 1 is represented by the relation of Equation 3.
【数３】 (Equation 3)
【００２１】また、式２中のＲtは共振器等価回路にお
ける全損失抵抗（32、33、36の合計）からＲmを除いたも
のであり、Ｒmは被測定物に漏れた共振器電磁界が受け
る水分損失に対応する抵抗である。In the equation 2, R t is the value obtained by subtracting R m from the total loss resistance (total of 32, 33, and 36) in the resonator equivalent circuit, and R m is the resonator leaking to the device under test. It is a resistance corresponding to the water loss that the electromagnetic field receives.
【００２２】ここで、Ｘは，被測定物の損失に対応する
量（以下損失と呼ぶ）である。図３は損失Ｘに対する規
格化共振器出力電力Ｙの特性及び式４で与えられるＺの
値を表したグラフである。Here, X is an amount corresponding to the loss of the device under test (hereinafter referred to as loss). FIG. 3 is a graph showing the characteristic of the normalized resonator output power Y with respect to the loss X and the value of Z given by Equation 4.
【数４】 (Equation 4)
【００２３】良好度Ｑ1extは、Ｑ1ext＝ω ×（共振器
誘導器34と共振器容量器35に蓄積されているエネルギ
ー）／（発信回路の内部インピーダンス32で1秒間に失
われるエネルギー）で定義したものである。ここで、ω
は角周波数を示す。The degree of goodness Q 1ext is represented by Q 1ext = ω × (energy stored in the resonator inductor 34 and the resonator capacitor 35) / (energy lost in one second due to the internal impedance 32 of the transmission circuit). It is defined. Where ω
Indicates an angular frequency.
【００２４】その他の良好度Qも同様である。良好度Ｑ
2extは、Ｑ2ext＝ω×（共振器誘導器34と共振器容量器
35に蓄積されているエネルギー）／（出力検出器のイン
ピーダンス36で1秒間に失われるエネルギー）で定義し
たものである。良好度Ｑ0は、Ｑ0＝ω×（共振器誘導器
34と共振器容量器35に蓄積されているエネルギー）／
（共振器を構成する導体や誘電体で1秒間に失われるエ
ネルギー）で定義したものである。良好度Ｑmは、Ｑm＝
ω×（共振器誘導器34と共振器容量器35に蓄積されてい
るエネルギー）／（Rmで1秒間に失われるエネルギー）
で定義したものである。The same applies to other goodness factors Q. Goodness Q
2ext is Q 2ext = ω × (resonator inductor 34 and resonator capacitor
It is defined as (energy stored in 35) / (energy lost in one second due to output detector impedance 36). The goodness Q 0 is given by Q 0 = ω × (resonator inductor
Energy stored in 34 and resonator capacitor 35) /
(Energy lost per second by the conductors and dielectrics that make up the resonator). Goodness Q m is, Q m =
ω × (energy stored in resonator inductor 34 and resonator capacitor 35) / (energy lost per second at R m )
It is defined by.
【００２５】透過電力Ｔは、T=（出力検出器で消費され
る電力）／（アンテナ電力源31の有能電力）で定義する
ことができる。なお、「有能電力」とは、電力源が発生
することのできる最大の電力を示す。The transmitted power T can be defined by T = (power consumed by the output detector) / (effective power of the antenna power source 31). In addition, "available power" indicates the maximum power that can be generated by the power source.
【００２６】規格化共振器出力電力Yの「規格化」と
は、X=0のときY=1となるようにしたという意味である。
透過電力Tは色々な値を取るが、規格化共振器出力電力Y
の値は0と1の間になる。"Normalization" of the normalized resonator output power Y means that when X = 0, Y = 1.
The transmitted power T takes various values, but the normalized resonator output power Y
Is between 0 and 1.
【００２７】従来、検出用ダイオードは、等価回路で表
した場合の回路全体の抵抗（抵抗32、33、36の和）に比べ
て、ダイオードインピーダンスが十分に小さくなるよう
に選定していた。この場合、規格化共振器出力電力Ｙ
は、図３に示すように、Ｘの増加に対して（式１）の形
で減少する。また、√Ｙで示されるＺは、１／（１＋
Ｘ）の形で減少する。Ｙは検出用ダイオードの特性が２
乗特性のとき、Ｚは直線特性のときをそれぞれ示してい
る。Conventionally, the detection diode has been selected so that the diode impedance is sufficiently smaller than the resistance of the entire circuit (the sum of the resistances 32, 33, and 36) when represented by an equivalent circuit. In this case, the normalized resonator output power Y
Decreases in the form of (Equation 1) as X increases, as shown in FIG. Z represented by ΔY is 1 / (1+
X). Y indicates that the characteristic of the detecting diode is 2
In the case of the square characteristic, Z indicates the case of the linear characteristic.
【００２８】規格化共振器出力電力Ｙは、規格化損失Ｘ
が小さいときには、１／(１＋Ｘ)2≒１−Ｘと近似され
て傾き−１の直線となる。これは、Ｙの変化がＸに比例
し、またはＺの変化がＸに比例することを意味してい
る。これに対して、Ｘが大きくなると、上記の近似は成
り立たず、ＹまたはＺの変化がＸに比例しなくなる。こ
れはダイオード出力の変化量と損失との関係が直線でな
くなることを意味する。また、Ｘが大きくなるにつれて
と規格化損失Ｘの変化に対して出力の変化が小さく出力
されるため、検出精度が低下していくものとなってい
る。The normalized resonator output power Y is equal to the normalized loss X
Is small, it is approximated as 1 / (1 + X) 2 ≒ 1−X and becomes a straight line with a slope of −1. This means that the change in Y is proportional to X or the change in Z is proportional to X. On the other hand, when X becomes large, the above approximation does not hold, and the change in Y or Z is not proportional to X. This means that the relationship between the amount of change in the diode output and the loss is not a straight line. Further, as X becomes larger, the change in the output is smaller than the change in the normalized loss X, so that the detection accuracy decreases.
【００２９】この結果、図３に示すように、従来のよう
に検出用ダイオードのダイオードインピーダンスが小さ
い場合には、発信器から電磁波を被測定物に照射・透過
した場合に、被測定物での損失が小さいときは検出器に
おいて損失に直線的に比例した出力が生じるが、被測定
物での損失が大きくなると出力が飽和傾向を示して次第
に比例しなくなる。そして、被測定物での損失が小さい
領域において検出精度が低下していた。As a result, as shown in FIG. 3, when the diode impedance of the detecting diode is small as in the prior art, when the electromagnetic wave is irradiated and transmitted from the transmitter to the measured object, the electromagnetic wave at the measured object is reduced. When the loss is small, an output linearly proportional to the loss is generated in the detector. However, when the loss in the device under test is large, the output tends to be saturated and gradually becomes less proportional. Then, the detection accuracy is reduced in a region where the loss in the device under test is small.
【００３０】このような場合に、出力を大きくするべく
回路電流を大きくしても、ダイオードに掛かる電圧は大
きくなるが、図４に示すように、ダイオードの電流−抵
抗値の特性が非直線型特性であり、電流が大きくなると
ダイオードのインピーダンスがさきほどより小さくなる
ので、結果として回路電流の増加ほどには出力が増加せ
ず測定精度が良くならなかった。In such a case, even if the circuit current is increased to increase the output, the voltage applied to the diode increases, but as shown in FIG. 4, the current-resistance characteristic of the diode is non-linear. The characteristic is that when the current increases, the impedance of the diode becomes smaller as before, and as a result, the output does not increase as much as the circuit current increases, and the measurement accuracy does not improve.
【００３１】そこで、本発明に係る水分量検査装置は、
出力検出器の検出用ダイオードのインピーダンス36を十
分に大きくした。検出用ダイオードのダイオードインピ
ーダンス36を大きくすると、図４に示すダイオードの電
流−抵抗値の特性が回路全体として無視できなくなる。
このとき共振器損失抵抗33が小さい場合は、回路電流が
大きくなり、検出用ダイオードのダイオードインピーダ
ンスが小さくなって、検出用ダイオードの出力は飽和す
る傾向を示す。このとき損失に対するダイオード出力の
変化も飽和傾向になる。また、共振器損失抵抗33が大き
い場合は、回路電流が小さくなり、検出用ダイオードの
ダイオードインピーダンスが大きくなって、検出用ダイ
オードの出力は飽和する傾向を示す。このときも損失に
対してダイオード出力の変化も飽和傾向になる。即ち、
共振器損失抵抗33が小さい場合及び大きい場合の両方
で、損失に対してダイオード出力の変化が飽和傾向にな
るので、共振器損失抵抗33に対して直線的に比例した出
力が得られるようになる。Therefore, the water content inspection apparatus according to the present invention
The impedance 36 of the detection diode of the output detector was made sufficiently large. If the diode impedance 36 of the detecting diode is increased, the current-resistance characteristics of the diode shown in FIG. 4 cannot be ignored as a whole circuit.
At this time, if the resonator loss resistance 33 is small, the circuit current increases, the diode impedance of the detection diode decreases, and the output of the detection diode tends to saturate. At this time, the change in the diode output with respect to the loss also tends to be saturated. When the resonator loss resistance 33 is large, the circuit current is small, the diode impedance of the detection diode is large, and the output of the detection diode tends to be saturated. At this time, the change in the diode output tends to be saturated with respect to the loss. That is,
In both cases where the resonator loss resistance 33 is small and large, the change in the diode output tends to saturate with respect to the loss, so that an output linearly proportional to the resonator loss resistance 33 can be obtained. .
【００３２】さらに、ダイオードインピーダンスを大き
くすることにより、回路の電流が小さいときでもダイオ
ードに掛かる電圧はある程度大きいので、より大きな出
力が得られるから検出精度が保障されるようになる。Further, by increasing the diode impedance, the voltage applied to the diode is large to some extent even when the current of the circuit is small, so that a larger output can be obtained, so that the detection accuracy can be guaranteed.
【００３３】なお、検出器の検出用ダイオードは、ダイ
オードの電流−抵抗値の特性を考慮して、回路電流の大
きいところで生じる飽和傾向と、回路電流の小さいとこ
ろで生じる飽和傾向を組み合わせて、損失に対して直線
的な出力結果が得られるものを選定することが望まし
い。The detection diode of the detector combines a saturation tendency occurring at a large circuit current with a saturation tendency occurring at a small circuit current in consideration of the current-resistance characteristics of the diode to reduce loss. On the other hand, it is desirable to select one that can obtain a linear output result.
【００３４】具体的には、等価回路で表した場合に、検
出用ダイオードのダイオードインピーダンス36が、発信
器の抵抗32と共振器損失抵抗33の和に比べて無視できな
い大きさ、例えば、1/10以上にすることにより、損失に
対して直線的な出力結果が得られるようになる。より好
適には、検出用ダイオードのダイオードインピーダンス
は、発信器の抵抗32と共振器損失抵抗33の和に比べて1/
3〜１倍程度の大きさで選定することが好ましい。Specifically, when represented by an equivalent circuit, the diode impedance 36 of the detecting diode is not negligible compared to the sum of the oscillator resistance 32 and the resonator loss resistance 33, for example, 1 / With a value of 10 or more, a linear output result can be obtained with respect to the loss. More preferably, the diode impedance of the detection diode is 1 / compared to the sum of the oscillator resistance 32 and the resonator loss resistance 33.
It is preferable to select a size about 3 to 1 times.
【００３５】本発明の水分量測定センサ20は、上記理論
に基づいて検出器を構成しており、検出用ダイオードの
ダイオードインピーダンスを大きくしたので、被測定物
の水分量の変化（Ｘ）に対して、水分量測定センサ20の
出力（Ｙ又はＺ）が均一に変化し、被測定物の水分量が
多い場合でも精度良く水分量を測定することができる。The water content measuring sensor 20 of the present invention constitutes a detector based on the above theory, and the diode impedance of the detecting diode is increased. As a result, the output (Y or Z) of the water content measurement sensor 20 changes uniformly, and the water content can be measured with high accuracy even when the measured object has a large water content.
【００３６】この水分量測定センサ20の出力ケーブル28
は、図１に示すように、出力電圧を被測定物に含まれる
水分量に換算する演算手段51に接続してあり、その測定
結果を出力手段としての表示装置52に表示するようにな
っている。演算手段51は、水分量測定センサ20の電気的
出力、（例えば、出力電圧）を基に、被測定物の水分量
を求めるようになっている。表示装置52は、表示器54、
操作スイッチ55、プリンター56およびＣＰＵを内蔵した
制御部（図示省略）で構成されており、操作スイッチ55
の操作に基づいて、演算手段51の測定結果を表示器54に
表示し、また、測定結果をプリンター56から出力できる
ようになっている。なお、演算手段51は図１に示すよう
に別の演算処理装置を併設しても良いし、表示装置に内
蔵しても良い。The output cable 28 of the moisture content measuring sensor 20
As shown in FIG. 1, is connected to a calculating means 51 for converting the output voltage into a moisture content contained in the object to be measured, and the measurement result is displayed on a display device 52 as an output means. I have. The calculating means 51 obtains the moisture content of the measured object based on the electrical output of the moisture content measuring sensor 20 (for example, output voltage). The display device 52 includes a display device 54,
An operation switch 55, a printer 56, and a control unit (not shown) having a built-in CPU are configured.
Based on the above operation, the measurement result of the calculation means 51 is displayed on the display unit 54, and the measurement result can be output from the printer 56. The arithmetic means 51 may be provided with another arithmetic processing device as shown in FIG. 1, or may be built in the display device.
【００３７】この水分量測定センサ20は、作業者が手動
で操作して保護セラミックス25の表面から被測定物へ電
磁波を発信し、被測定物へ浸透した電磁波をマイクロス
トリップ共振器アンテナ21で受信して、演算手段51で水
分量に換算して当該被測定物に含まれる水分量を測定す
ることができる。The moisture content measuring sensor 20 transmits electromagnetic waves from the surface of the protective ceramics 25 to the object to be measured by an operator manually operated, and receives the electromagnetic waves permeating the object to be measured by the microstrip resonator antenna 21. Then, the amount of moisture contained in the measured object can be measured by calculating the amount of moisture by the calculating means 51.
【００３８】また、この水分検出センサ20は、図５(a)
(b)に示すように、被測定物43を収容する測定容器41の
側面に昇降可能に取り付けて、測定容器41内の被測定物
43に満遍なく電磁波を浸透させてこれに含まれる水分量
を測定するように構成することができる。この測定容器
41は、上記水分量測定センサ20を外部から取り付ける構
造になっていて、水分量測定センサ面は誘電率の低い樹
脂42を使用する。これは、電磁波の吸収を最低減にする
ことを目的とする。水分量測定センサ20から発生される
電磁波は、この測定樹脂を通過して、被測定物43（たと
えば、フレッシュコンクリート）の水分量の計測を行う
ことができる。Further, this moisture detecting sensor 20 is shown in FIG.
As shown in (b), the measurement object 41 in the measurement container 41 is attached to the side of the measurement container 41
An arrangement can be made in which electromagnetic waves penetrate evenly into 43 and the amount of water contained therein is measured. This measuring container
Reference numeral 41 denotes a structure in which the above-mentioned moisture content measuring sensor 20 is attached from the outside. The moisture content measuring sensor surface uses a resin 42 having a low dielectric constant. This aims at minimizing the absorption of electromagnetic waves. The electromagnetic wave generated from the moisture content measurement sensor 20 passes through the measurement resin, and can measure the moisture content of the object 43 (for example, fresh concrete).
【００３９】また、被測定物43の水分量検出を均一にす
るため、水分量測定センサ20を昇降させる昇降機構47が
ある。昇降機構47は、昇降モータ44の回転軸に構成した
ボールねじ45に水分量測定センサ20を取り付けたもので
ある。この昇降機構47に取り付けた水分量測定センサ20
は、測定容器41の側面に沿って上下に移動させて複数箇
所で被測定物43の水分量を測定するから、測定容器41内
の被測定物43を満遍なく測定することができる。このよ
うに測定容器41内の被測定物43を複数箇所で測定してい
るので、粗骨材の含まれる割合で水分量が異なるフレッ
シュコンクリートでも、被測定物43全体の平均的な水分
量を正確に測定することができるようになる。There is an elevating mechanism 47 for raising and lowering the water content measuring sensor 20 in order to make the detection of the water content of the object 43 uniform. The elevating mechanism 47 has a structure in which the water content measuring sensor 20 is attached to a ball screw 45 formed on a rotating shaft of the elevating motor 44. The water content measuring sensor 20 attached to the lifting mechanism 47
Is moved up and down along the side surface of the measurement container 41 to measure the water content of the object 43 at a plurality of locations, so that the object 43 in the measurement container 41 can be measured evenly. As described above, since the measured object 43 in the measuring container 41 is measured at a plurality of locations, even in fresh concrete having a different moisture content depending on the proportion of coarse aggregate contained, the average moisture content of the entire measured object 43 is reduced. It will be possible to measure accurately.
【００４０】この水分量測定装置の使用例としては、フ
レッシュコンクリートを測定容器41に入れる。そして、
表示装置52の操作スイッチ55を操作することにより、測
定容器41につけられた昇降機構47が動作し、水分量測定
センサ20が測定容器41の側面に沿って上下に移動しなが
ら測定を開始する。被測定物43の水分量を一定に測定す
るため、各点で水分量の計測をおこなう。水分量測定セ
ンサ20からの信号は出力ケーブル28にて演算手段51に送
られる。演算手段51では、水分量測定センサ20からの多
点の測定データを、例えば最小二乗法による回帰分析を
行い被測定物全体に平均化した水分量を求める。As an example of use of this moisture content measuring device, fresh concrete is put in a measuring container 41. And
By operating the operation switch 55 of the display device 52, the elevating mechanism 47 attached to the measurement container 41 operates, and the water content measurement sensor 20 starts measurement while moving up and down along the side surface of the measurement container 41. In order to constantly measure the water content of the object 43, the water content is measured at each point. The signal from the moisture content measuring sensor 20 is sent to the calculating means 51 via the output cable 28. The calculating means 51 obtains the water content averaged over the whole measured object by performing, for example, a regression analysis on the multipoint measurement data from the water content measurement sensor 20 by a least squares method.
【００４１】以上、本発明に係る水分量測定装置の一実
施形態を説明したが、本発明は上記に限定されるもので
はない。The embodiment of the water content measuring device according to the present invention has been described above, but the present invention is not limited to the above.
【００４２】本発明の水分量測定センサは、特に、フレ
ッシュコンクリートや砂及び砂利等の水分量の検出装置
に適用できるが、用途はこれに限定されず、例えば、モ
ルタルや木材などの水分量も測定できる。The sensor for measuring the amount of water of the present invention can be applied particularly to a device for detecting the amount of water such as fresh concrete, sand and gravel, but the application is not limited thereto. Can be measured.
【００４３】[0043]
【発明の効果】請求項１に記載の水分量測定センサは、
電磁界を被測定物に浸透させ、そのときの電磁界吸収か
ら水分量を測定するマイクロ波を使用した水分量測定技
術において、被測定物における電磁界損失に対して直線
的に比例した出力特性を生じる検出用負荷を有している
ことを特徴とする。この水分量測定センサは、被測定物
に電磁界を浸透させ、被測定物に浸透した電磁波を受信
することにより被測定物に含まれる水分量を測ることが
できるから、瞬時に水分量を測ることができる。また、
被測定物に含まれる水分量に対して直線的に比例した電
気的出力を生じさせることができるので、被測定物に含
まれる水分量を均一な精度で測定することができる。According to the first aspect of the present invention, there is provided a sensor for measuring a water content.
In the moisture content measurement technology using microwaves, which measure the moisture content from the electromagnetic field absorption by causing the electromagnetic field to penetrate the DUT, the output characteristics are linearly proportional to the EMF loss in the DUT Characterized by having a detection load that causes This moisture content measurement sensor can measure the moisture content instantaneously because it can measure the moisture content contained in the measurement object by infiltrating an electromagnetic field into the measurement object and receiving the electromagnetic wave penetrating the measurement object. be able to. Also,
Since an electrical output linearly proportional to the amount of water contained in the object can be generated, the amount of water contained in the object can be measured with uniform accuracy.
【００４４】請求項２に記載の水分量測定センサは、被
測定物に電磁波を発信する発信部と、前記被測定物に浸
透した電磁波を受信する受信部とを備え、電磁界を被測
定物に浸透させ、そのときの電磁界吸収から水分量を測
定する電磁波を使用した水分量測定技術において、前記
発信部での抵抗を示す第１の抵抗、被測定物の共振によ
る損失を示す第２の抵抗、コイル及びコンデンサ、受信
部の検出用負荷での抵抗を示す第３の抵抗を直列に繋い
で水分量測定センサの等価回路を表した場合に、第３の
抵抗の抵抗値が第１の抵抗及び第２の抵抗の各抵抗値の
合計の少なくとも１/10以上であって、被測定物におけ
る電磁界損失に対して直線的に比例した出力特性を生じ
ることを特徴とする。この水分量測定センサは、被測定
物の検出水分量と検出出力が直線的に比例する出力が得
られるとともに、受信部の検出用負荷の抵抗が第１の抵
抗及び第２の抵抗の各抵抗値に対して大きいから、検出
用負荷の出力値が大きくなるので検出精度が良くなる。According to a second aspect of the present invention, there is provided a moisture content measuring sensor comprising: a transmitting section for transmitting an electromagnetic wave to an object to be measured; and a receiving section for receiving an electromagnetic wave permeating the object to be measured. In a moisture content measurement technique using an electromagnetic wave for measuring the moisture content from electromagnetic field absorption at that time, a first resistance indicating a resistance at the transmitting portion, and a second resistance indicating a loss due to resonance of an object to be measured. The resistance value of the third resistor is equal to the first resistance value when an equivalent circuit of the moisture content measuring sensor is represented by connecting in series a resistor, a coil and a capacitor, and a third resistor indicating a resistance at a detection load of the receiving unit. The output characteristic is at least 1/10 or more of the sum of the resistance values of the first and second resistors and is linearly proportional to the electromagnetic field loss in the device under test. With this moisture content measurement sensor, an output in which the detected moisture content of the object to be measured and the detection output are linearly proportional is obtained, and the resistance of the detection load of the receiving unit is the resistance of the first resistance and the second resistance. Since the value is larger than the value, the output value of the detection load increases, and the detection accuracy is improved.
【００４５】請求項３に記載の水分量測定センサは、被
測定物を収容する測定容器と、前記測定容器の外面に沿
って移動可能に取り付けた請求項１に記載の水分量測定
センサと、前記水分量測定センサと測定容器とを相対移
動させる移動機構と、前記水分量測定センサで測定され
た被測定物の水分量のデータを出力する出力手段とを備
え、前記水分量測定センサと測定容器とを相対移動させ
て複数箇所で被測定物に電磁界を浸透させて被測定物に
含まれる水分量を測定し、被測定物の平均的な水分量を
検出するので、被測定物全体の平均的な水分量を正確に
測定することができる。According to a third aspect of the present invention, there is provided a moisture content measuring sensor, comprising: a measuring container for accommodating an object to be measured; A movement mechanism for relatively moving the water content measurement sensor and the measurement container; and output means for outputting data on the water content of the measured object measured by the water content measurement sensor. The container and the container are moved relative to each other to penetrate the electromagnetic field into the measured object at a plurality of locations to measure the amount of water contained in the measured object and detect the average amount of water in the measured object. Can be accurately measured.
【００４６】本発明の水分量測定装置は、フレッシュコ
ンクリート、砂などの水分量の検出に好適である。The water content measuring device of the present invention is suitable for detecting the water content of fresh concrete, sand and the like.
【００４７】[0047]
【図１】 水分量測定センサを示す分解斜視図。FIG. 1 is an exploded perspective view showing a moisture content measurement sensor.
【図２】 本発明の一実施形態に係る水分量測定装置の
等価回路図。FIG. 2 is an equivalent circuit diagram of the moisture content measuring device according to one embodiment of the present invention.
【図３】 規格化損失Ｘと出力電力Ｙ，Ｚの相関グラ
フ。FIG. 3 is a correlation graph of a normalized loss X and output powers Y and Z.
【図４】 検出用ダイオードの電流と抵抗値の相関グラ
フ。FIG. 4 is a correlation graph of current and resistance of a detection diode.
【図５】 (a)は本発明の一実施形態に係る水分量測定
装置の側面図、(b)はその水分量測定装置の正面図。5A is a side view of a moisture content measuring device according to an embodiment of the present invention, and FIG. 5B is a front view of the moisture content measuring device.
20 水分量測定センサ 21 マイクロストリップ共振器アンテナ 22 発信回路基板 23 ＣＰＵコントロール基板 24 ケース 25 保護セラミックス 26 Ｏリング 28 出力ケーブル 31 アンテナ電力源 32 発信回路の内部インピーダンス 33 共振器損失抵抗 34 共振器誘導器 35 共振器容量器 36 出力検出器のインピーダンス 41 測定容器 42 樹脂 43 被測定物 44 モータ 45 ボールねじ 47 昇降機構 51 演算手段 52 表示装置 54 表示器 55 操作スイッチ 56 プリンター 20 Water content measurement sensor 21 Microstrip resonator antenna 22 Oscillator circuit board 23 CPU control board 24 Case 25 Protective ceramic 26 O-ring 28 Output cable 31 Antenna power source 32 Internal impedance of oscillator circuit 33 Resonator loss resistance 34 Resonator inductor 35 Resonator capacitor 36 Impedance of output detector 41 Measurement container 42 Resin 43 DUT 44 Motor 45 Ball screw 47 Elevating mechanism 51 Calculation unit 52 Display unit 54 Display unit 55 Operation switch 56 Printer
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中村 征嗣 大阪府大阪市淀川区田川３丁目５番11号 タケモトデンキ株式会社内 Ｆターム(参考） 4G056 AA06 CA03 CB15 DA08 5J006 HB03 LA11 MA07 MB02 NA05 PA01 PB01 5J045 AA01 AA06 DA10 EA07 GA05 HA03 5J046 AA01 AA07 AB13 PA07 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Seiji Nakamura 3-5-11 Tagawa, Yodogawa-ku, Osaka-shi Takemoto Denki Co., Ltd. F-term (reference) 4G056 AA06 CA03 CB15 DA08 5J006 HB03 LA11 MA07 MB02 NA05 PA01 PB01 5J045 AA01 AA06 DA10 EA07 GA05 HA03 5J046 AA01 AA07 AB13 PA07
Claims (4)
の電磁界吸収から水分量を測定する電磁波を使用した水
分量測定技術において、被測定物における電磁界損失に
対して直線的に比例した出力特性を生じる検出用負荷を
有していることを特徴とする水分量測定センサ。In a moisture content measuring technique using an electromagnetic wave for measuring an amount of moisture from an electromagnetic field absorbed by an electromagnetic field penetrating an object to be measured, the electromagnetic field loss in the object to be measured is linearly reduced. A moisture measurement sensor having a detection load that produces a proportional output characteristic.
前記被測定物に浸透した電磁波を受信する受信部とを備
え、電磁界を被測定物に浸透させ、そのときの電磁界吸
収から水分量を測定する電磁波を使用した水分量測定技
術において、 前記発信部での抵抗を示す第１の抵抗、被測定物の共振
による損失を示す第２の抵抗、コイル及びコンデンサ、
受信部の検出用負荷での抵抗を示す第３の抵抗を直列に
繋いで水分量測定センサの等価回路を表した場合に、 第３の抵抗の抵抗値が第１の抵抗及び第２の抵抗の各抵
抗値の合計の少なくとも１/10以上であって、被測定物
における電磁界損失に対して直線的に比例した出力特性
を生じることを特徴とする水分量測定センサ。2. A transmitter for transmitting an electromagnetic wave to a device under test,
A receiving unit that receives the electromagnetic wave that has permeated the object to be measured, the electromagnetic field penetrates the object to be measured, and a moisture content measurement technique using electromagnetic waves to measure moisture content from electromagnetic field absorption at that time, A first resistor indicating a resistance at the transmission unit, a second resistor indicating a loss due to resonance of the device under test, a coil and a capacitor,
In a case where an equivalent circuit of the moisture content measuring sensor is represented by connecting in series a third resistor indicating the resistance at the detection load of the receiving unit, the resistance value of the third resistor is equal to the first resistance and the second resistance. A water content measurement sensor that produces an output characteristic that is at least 1/10 or more of the sum of the respective resistance values and is linearly proportional to the electromagnetic field loss in the measured object.
定容器の外面に沿って移動可能に取り付けた請求項１に
記載の水分量測定センサと、前記水分量測定センサと測
定容器とを相対移動させる移動機構と、前記水分量測定
センサで測定された被測定物の水分量のデータを出力す
る出力手段とを備え、前記水分量測定センサと測定容器
とを相対移動させて複数箇所で被測定物に電磁界を浸透
させて被測定物に含まれる水分量を測定し、被測定物の
平均的な水分量を検出することを特徴とする水分量測定
装置。3. The measuring container for accommodating an object to be measured, the moisture content measuring sensor according to claim 1, which is movably mounted along the outer surface of the measuring container, and the moisture content measuring sensor and the measuring container. A moving mechanism for performing relative movement, and output means for outputting data on the moisture content of the object measured by the moisture content measurement sensor, and the relative movement between the moisture content measurement sensor and the measurement container is performed at a plurality of locations. A moisture content measuring device characterized by measuring an amount of water contained in a measured object by infiltrating an electromagnetic field into the measured object and detecting an average moisture content of the measured object.
砂のいずれかであることを特徴とする請求項３に記載の
水分量測定装置。4. The apparatus according to claim 3, wherein the object to be measured is one of fresh concrete and sand.
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Cited By (3)
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| KR100684925B1 (en) | 2005-07-25 | 2007-02-20 | 연세대학교 산학협력단 | Humidity Sensor and Fabricating Method of the Same |
| KR100753801B1 (en) * | 2006-10-24 | 2007-08-31 | 연세대학교 산학협력단 | Humidity Sensor and Fabricating Method of the Same |
| JP2016119647A (en) * | 2014-12-19 | 2016-06-30 | 日本電波工業株式会社 | Oscillator |
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