JP6784459B2 - Non-destructive, continuous, automatic measurement Peltier thermocouple cyclometer - Google Patents
Non-destructive, continuous, automatic measurement Peltier thermocouple cyclometer Download PDFInfo
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高糖度メロンや高糖度トマトの生産は、ストレス(水ポテンシャルとも呼ばれる)を掛けて栽培すると言われ、土耕栽培では潅水を控えて水切りを行う方法とか、水耕栽培では食塩NaClを混ぜて根域ストレスを掛けて育てている。しかし、作物ストレスや土壌中ストレスを、非破壊・連続・自動計測したデータを見たことがなく、かつ誰も計測できなかったのが現況である。 The production of high sugar content melons and high sugar content tomatoes is said to be cultivated under stress (also called water potential). In soil cultivation, irrigation is avoided and drainage is performed. In hydroponics, salt NaCl is mixed and rooted. Growing with regional stress. However, the current situation is that we have never seen non-destructive, continuous, and automatic measurement data for crop stress and soil stress, and no one could measure it.
本発明は、葉、茎、根、果実等の作物体ストレスや土壌中ストレスを非破壊、連続、自動計測するペルチィア型熱電対サイクロメータを提供するものであり、溶液の浸透圧を計測する医療関係の蒸気圧法浸透圧計としても利用できる。 The present invention provides a Perthia-type thermocouple cyclometer that non-destructively, continuously, and automatically measures stress on crops such as leaves, stems, roots, and fruits, and stress in soil, and is a medical treatment that measures the osmotic pressure of a solution. It can also be used as a related steam pressure osmotic meter.
高糖度なメロン、トマト、イチゴを生産する高品質栽培は、作物体の生体情報に基づく栽培管理が必要であるが、これまで誰も計測できなかったため、農家の勘と経験に頼ってきた。しかし、TPPによって農業もグローバル社会の中で競争が激化し、付加価値の付いた農産物生産が求められており、データに基づく合理的な次世代型農業技術の開発が望まれている。 High-quality cultivation that produces high sugar content melons, tomatoes, and strawberries requires cultivation management based on the biological information of the crop, but since no one could measure it so far, it relied on the intuition and experience of farmers. However, the TPP has intensified competition in agriculture in the global society, and the production of value-added agricultural products is required, and the development of rational next-generation agricultural technology based on data is desired.
本発明は、作物が水を吸い上げる要求度をエネルギー値で示した作物水分ポテンシャル(作物ストレス)や、土壌粒子と土壌水が結合している力をエネルギー値で示した土壌の全水分ポテンシャル(マトリックポテンシャル+浸透ポテンシャル+重力ポテンシャルの和で示される)や、溶液の浸透圧を示した浸透ポテンシャルを計測するものであり、計測値はマイナス値で、MPa単位で通常表示される。 In the present invention, the crop water potential (crop stress), which indicates the degree to which a crop sucks water, is indicated by an energy value, and the total water potential of soil (matric), which indicates the force of binding soil particles and soil water by an energy value. (Indicated by the sum of potential + permeation potential + gravitational potential) and the permeation potential indicating the osmotic pressure of the solution are measured, and the measured value is a negative value and is usually displayed in MPa units.
作物ストレス(水ポテンシャル)の直接的計測は、Boyerが著書(1995年)で詳述しているように、プレッシャーチャンバー法と熱電対サイクロメータ法の2方法がある。我が国では、葉を切り取って計測するプレッシャーチャンバー法が簡便で取り扱いやすいため広く用いられてきたが、葉を葉柄で切り取って計測するため次第に着生葉が少なくなり、継続的な計測ができない致命的な欠点があった。 As detailed in his book (1995) by Boyer, there are two methods for direct measurement of crop stress (water potential): the pressure chamber method and the thermocouple cyclometer method. In Japan, the pressure chamber method of cutting and measuring leaves has been widely used because it is simple and easy to handle, but since the leaves are cut and measured with petioles, the number of settled leaves gradually decreases, which is fatal and continuous measurement is not possible. There was a drawback.
一方、測定試料の水蒸気圧と平衡させたチャンバー内の相対湿度を計測することによって水ポテンシャルを求める熱電対サイクロメータ法は精度の良い計測法であるが、多くの問題点があった。 On the other hand, the thermocouple cyclometer method for obtaining the water potential by measuring the relative humidity in the chamber equilibrated with the water vapor pressure of the measurement sample is an accurate measurement method, but has many problems.
市販のアメリカ製サイクロメータは手動操作の計測器であり、(1)手動操作の計測手順が複雑である、(2)計測器上のメータの針の動きが滞留したところの起電力を目視で読み取るが、その読み取り値が不安定で、かつ不明瞭である、(3)読み取った起電力を事前に作成した検量線に代入して水ポテンシャル値を演算するが、迅速に直接表示できない、(4)計測時の温度変動が測定誤差を与える、(5)サンプルとの蒸気圧平衡に長時間を要する等の理由から、多くのサイクロメータ(推定約15,000台)が1970年代に輸入されたにも関わらず、我が国ではほとんど利用されなかった。 Commercially available American cyclometers are manually operated measuring instruments, and (1) the manual operation measuring procedure is complicated, and (2) the electromotive force where the movement of the meter needle on the measuring instrument is stagnant is visually observed. It is read, but the reading is unstable and unclear. (3) The read electromotive force is substituted into the calibration curve created in advance to calculate the water potential value, but it cannot be displayed directly quickly (. Many cyclometers (estimated about 15,000) were imported in the 1970s because 4) temperature fluctuations during measurement give measurement errors, and (5) it takes a long time to balance the vapor pressure with the sample. Nevertheless, it was rarely used in Japan.
熱電対サイクロメータの使用実績は、恒温室内で採取した土壌や切り取った葉をサンプルチャンバー内に詰めて水ポテンシャルを計測した2〜3例の論文に見られるのみで、現場圃場での作物体や土壌での水ポテンシャルを非破壊で連続計測した報告は全くない。このように、熱電対サイクロメータは温度変動のある現場測定には不向きであると判断され、半世紀以上見捨てられてきた。 Actual use of the thermocouple psychrometer is only seen in a few cases paper was stuffed with soil and cut leaves collected at constant greenhouse in the sample chamber and measuring the water potential, crops with onsite field There are no reports of non-destructive continuous measurements of water potential in the body or soil. Thus, thermocouple cyclometers have been abandoned for more than half a century because they have been judged unsuitable for on-site measurements with temperature fluctuations.
そのうえ、市販サイクロメータの全45頁の計測マニュアルは、乾湿温度差に相当する露点温度を示す変曲点起電力を計測するサイクロメータ法と、間欠的な時分割電流によって湿接点を露点温度に一定に維持するハイグロメータ法を紹介しているが、そのほとんどの頁はハイグロメータ法の説明に終始してハイグロメータ法を推奨しており、サイクロメータ法の説明はたった10行にすぎない。ハイグロメータ法は、露点温度を一定にするため間欠電流をタイミング良く流す高度な回路を持つ優れた計測法ではあるが、温度に依存する間欠係数Πvを設定しなければならず、恒温室での試験に限定される。それに対してサイクロメータ法は、測定値の温度補正式が提示されており、温度変化する現地圃場でも使用できるので便利であるが、一般ユーザーには理解されなかった。 In addition, the 45-page measurement manual for commercial cyclometers uses the cyclometer method to measure the inflection point electromotive force, which indicates the dew point temperature corresponding to the dry-wet temperature difference, and the intermittent time-division current to bring the wet contact to the dew point temperature. Although it introduces the high-gromometer method that keeps it constant, most of the pages recommend the high-gromometer method from beginning to end with the explanation of the high-gromometer method, and the explanation of the cyclometer method is only 10 lines. The hygrometer method is an excellent measurement method with an advanced circuit that allows intermittent current to flow in a timely manner in order to keep the dew point temperature constant, but it is necessary to set an intermittent coefficient Πv that depends on the temperature, and in a constant temperature room. Limited to exams. On the other hand, the cyclometer method is convenient because it presents a temperature compensation formula for measured values and can be used in a field where the temperature changes , but it was not understood by general users.
そのため、作物体の水ストレス計測に関する国内文献は、次の引例のように全て間接的計測法が提案されており、最終的にはプレッシャーチャンバー法による測定値(リーフポテンシャルではなく木部水ポテンシャルと呼ばれている)と相関関係を求めた検量線から、水ポテンシャルを間接的に算出している。 Therefore, all domestic literature on water stress measurement of crops proposes indirect measurement methods as shown in the following reference, and finally the measured values by the pressure chamber method (Kibe water potential instead of leaf potential). The water potential is indirectly calculated from the calibration curve obtained from the correlation with (called).
特許文献1の作物の水ストレス判定方法は13Cと12Cの同位元素の比率で水ストレスを判断する方法が開示されているが、放射性同位元素を使用しているため、現場(圃場)で安全かつ簡単には計測できない。 The method for determining water stress of crops in Patent Document 1 discloses a method for determining water stress by the ratio of 13 C and 12 C isotopes, but since a radioisotope is used, it is used in the field (field). It cannot be measured safely and easily.
特許文献2の作物体の水ストレス診断方法は作物体と土壌とに非分極性電極を取り付けて両極の電位差によって水ストレスを計測する方法が開示されているが、作物の種類や土壌タイプ、土壌水分によって電気出力が大きく異なり、計測精度の点で疑問が残る。 The method for diagnosing water stress in a crop body of Patent Document 2 discloses a method in which a non-polarizing electrode is attached to the crop body and the soil to measure water stress by the potential difference between the two poles, but the type of crop, soil type, and soil. The electrical output varies greatly depending on the water content, leaving doubts about measurement accuracy.
特許文献3の作物のストレス応答計測及び装置は、磁界発生装置とマイクロ波を照射させて測定を行う表面コイル型共振器に、非破壊の作物試料を対応させて空間部に配置し、作物のストレス応答の結果として生成するフリーラジカルおよび活性酸素の挙動を観測する方法であるが、作物体のストレスに対する相対単位の信号強度の経時変化を見ているだけで、水ストレス(水ポテンシャル)の絶対評価は行われていない。 The stress response measurement and device for crops in Patent Document 3 is a surface coil type resonator that irradiates a magnetic field generator and microwaves for measurement, and a non-destructive crop sample is placed in a space corresponding to the stress response of the crop. It is a method of observing the behavior of free radicals and active oxygen generated as a result of stress response, but the absolute water stress (water potential) is absolute just by looking at the change over time in the signal intensity of the relative unit with respect to the stress of the crop body. No evaluation has been done.
特許文献4の作物の受けるストレスの測定方法は緑葉と標準白色板から反射する分光反射率特性から水ストレスを評価する方法が開示されており、反射光と透過光を分光して500〜800nmの連続波長に対して分光反射率を算出して、それが急激に立ち上がる波長域を求め、その波長域の中心波長の推移から水ストレスを評価するが、高価な分光器が必要で、かつ精度が十分でなかったと発明者自身がその後提出した特開2009−109363に記述している。 As a method for measuring the stress received by a crop in Patent Document 4, a method for evaluating water stress from the spectral reflectance characteristics reflected from green leaves and a standard white plate is disclosed, and the reflected light and transmitted light are separated to a wavelength of 500 to 800 nm. Spectral reflectance is calculated for continuous wavelengths, the wavelength range in which it rises sharply is obtained, and water stress is evaluated from the transition of the central wavelength in that wavelength range, but an expensive spectroscope is required and the accuracy is high. It is described in Japanese Patent Application Laid-Open No. 2009-109363 that the inventor himself subsequently submitted that it was not sufficient.
特許文献5の作物の水ストレス計測法及び装置は、任意時点での分光特性値を変数として多変量解析法から水ストレスを算出するが、最初にプレッシャーチャンバー法で実測した葉の水ポテンシャルを基準値として入力しておかねばならず、計測器単独で水ストレスを絶対評価できないので精度が悪い。 In the water stress measurement method and apparatus for crops of Patent Document 5, the water stress is calculated from the multivariate analysis method using the spectral characteristic value at an arbitrary time point as a variable, but the water potential of the leaves actually measured by the pressure chamber method is used as a reference. It must be entered as a value, and the accuracy is poor because the water stress cannot be evaluated by the measuring instrument alone.
特許文献6のストレスに対する作物体の適応応答反応の測定法は、作物体にマイクロウェーブを照射し、作物体から反射される信号から複素誘電率εを求め、この複素誘電率εの周波数特性から作物体に加わったストレス適応応答を検出しているが、相対的な変動を計測しているだけで、絶対的な計測値を求めることはできない。 In the method for measuring the adaptive response response of a crop body to stress in Patent Document 6, the crop body is irradiated with a microwave, the complex permittivity ε is obtained from the signal reflected from the crop body, and the complex permittivity ε is obtained from the frequency characteristics of the complex permittivity ε. Although the stress adaptation response applied to the crop body is detected, it is not possible to obtain an absolute measured value only by measuring the relative fluctuation.
特許文献7の作物体の適応応答測定装置及び作物体の適応応答測定法は、特許文献6の発明者がその延長線上で考案したものであり、作物体を挟むクリップ部に第1電極と第2電極の隙間を開けて配置し、その電極に所定の電気信号を引加し、その印加した電気信号の特性を計測して作物体のストレス応答を測定しているが、計測されたデータは複雑で解析できていない。 The adaptive response measuring device for the crop body and the adaptive response measuring method for the crop body of Patent Document 7 were devised by the inventor of Patent Document 6 on an extension line thereof, and the first electrode and the first electrode and the first electrode and the first electrode and the first The two electrodes are arranged with a gap between them, a predetermined electric signal is applied to the electrodes, and the characteristics of the applied electric signal are measured to measure the stress response of the crop body, but the measured data is It is complicated and cannot be analyzed.
特許文献8の水ポテンシャル測定方法及び水ポテンシャル測定装置は、作物の葉切片を異なる蛍光試薬溶液に1時間浸漬して、その蛍光画像の輝度から試料の水ポテンシャルを求めるものであるが、事前にプレッシャーチャンバー法の水ポテンシャル値と輝度との相関関係を求めておかねばならず、迅速な測定法とはいえない。 The water potential measuring method and the water potential measuring device of Patent Document 8 are for immersing a leaf section of a crop in a different fluorescent reagent solution for 1 hour and obtaining the water potential of a sample from the brightness of the fluorescent image. It is necessary to find the correlation between the water potential value of the pressure chamber method and the brightness, and it cannot be said that this is a rapid measurement method.
以上のように国内文献は間接的に作物体の水ストレスを計測しているのに対して、外国文献は、次の引例に見られるように全て直接的計測法である熱電対サイクロメータ法に関するもので、既に20年以上が経過している。
1973年の特許文献8は、小さなサンプルチャンバー内に測定サンプルを詰めて、サンプルホルダー内に挿入して密閉し、測定サンプルの水蒸気圧と平衡させたサンプルチャンバー内の相対湿度から水分ポテンシャルを求める計測法を記述しており、本特許を製品化したものが、まさしく市販されているWESCO社のサンプルチャンバーC−51と、露点を維持する回路を持つ露点マイクロボルトメータHR−33である。しかし、WESCO社製品は、室温が一定温度のとき熱電対上の露点温度を一定に維持できるハイグロメータ法を推奨しており、気温変動する圃場での計測は奨めていない。 Patent Document 8 of 1973 is a measurement in which a measurement sample is packed in a small sample chamber, inserted into a sample holder, sealed, and the water potential is obtained from the relative humidity in the sample chamber balanced with the water vapor pressure of the measurement sample. The method is described, and the commercialized products of this patent are the sample chamber C-51 manufactured by WESCO, which is commercially available, and the dew point microvolt meter HR-33 having a circuit for maintaining the dew point. However, WESCO's products recommend a high-glometer method that can maintain a constant dew point temperature on the thermocouple when the room temperature is constant, and do not recommend measurement in fields where the temperature fluctuates.
1974年の特許文献9は、葉の水ポテンシャルを非破壊で計測する50ミクロン厚さの銀ホイルで構成した小型の熱電対センサを提案しており、葉に簡単に取り付けることができるのが特徴であるが、熱電対センサのチャンバー内の湿接点のみの計測で、チャンバー内の気温計測がないので、温度補正ができないので誤差を生じる。 Patent Document 9 of 1974 proposes a small thermocouple sensor composed of a silver foil having a thickness of 50 microns that nondestructively measures the water potential of a leaf, and is characterized by being easily attached to a leaf. However, since only the wet contact in the chamber of the thermocouple sensor is measured and the temperature inside the chamber is not measured, the temperature cannot be corrected, which causes an error.
1981年の特許文献10は、水蒸気を通すシール材で熱電対を保護する構造を持つ土壌用のハイグロメータとサイクロメータを提案しており、WESCO社のPT−51土壌用センサとして市販されているが、シール材として使用されているセラミックカップに土壌塩類が蓄積して計測に影響を与えるとともに、チャンバー内の空間が大きいため3〜5時間の平衡時間を必要とし、潅水等による急激な水ポテンシャル変動の計測に対応できない。 Patent Document 10 of 1981 proposes a hygrometer and a cyclometer for soil having a structure for protecting a thermocouple with a sealing material that allows water vapor to pass through, and is commercially available as a sensor for PT-51 soil manufactured by WESCO. However, soil salts accumulate in the ceramic cup used as a sealing material, which affects the measurement, and the large space inside the chamber requires an equilibrium time of 3 to 5 hours, resulting in rapid water potential due to irrigation, etc. It cannot handle the measurement of fluctuations.
1990年の特許文献11は、スイッチで切り変えて多数点の計測ができるサイクロメータを開示しているが、切り替えスイッチで多数点を手動で順次計測することは当然のことである。 Patent Document 11 of 1990 discloses a cyclometer capable of measuring a large number of points by switching with a switch, but it is natural that a large number of points are manually sequentially measured with a changeover switch.
以上のように熱電対サイクロメータ法は、作物体や土壌の水ポテンシャルを直接計測できる計測法として諸外国では広く使用されて多くの論文が報告されてきたが、我が国では現場計測は不可能と判断されて全く使用されなかった。 As described above, the thermocouple cyclometer method has been widely used in other countries as a measurement method that can directly measure the water potential of crops and soil, and many papers have been reported, but on-site measurement is impossible in Japan. It was judged and never used.
本発明は、外国製品を模倣することなく、ペルチィア型熱電対サイクロメータを新たに製作して、その計測精度や再現性を詳細に検討した。その結果、温度変化の激しい現場においてリアルタイムに直接デジタル表示できる非破壊、連続、自動、現場計測できるペルチィア型熱電対サイクロメータを実現した。 In the present invention, a Peltier-type thermocouple cyclometer was newly manufactured without imitating a foreign product, and its measurement accuracy and reproducibility were examined in detail. As a result, we have realized a non-destructive, continuous, automatic, and on-site measurement Peltier thermocouple cyclometer that can be directly digitally displayed in real time in a field where temperature changes are drastic .
サイクロメータ法による水ポテンシャルの計測原理は、測定試料と蒸気圧平衡したチャンバー内の乾湿球の温度差から相対湿度を求め、下記のKelvin式から算出される化学ポテンシャル値(MPa単位)であり、絶対値である。
水ストレスΨ=エネルギー/体積=RT/V・lm(P/Po)
ここで、R:気体定数、T:絶対温度、V:水のモル体積、P/Po:相対湿度である。
The principle of measuring water potential by the cyclometer method is the chemical potential value (MPa unit) calculated from the Kelvin formula below by obtaining the relative humidity from the temperature difference between the dry and wet bulbs in the chamber where the vapor pressure is balanced with the measurement sample. It is an absolute value.
Water stress Ψ = energy / volume = RT / V ・ lm (P / Po)
Here, R: gas constant, T: absolute temperature, V: molar volume of water, P / Po: relative humidity.
Spanner(1951年)によって開発されたペルチィエ型サイクロメータは、チャンバー内の気温と平衡した熱電対のゼーベック起電力を最初0μVにオフセットしたのち、逆に電流を流すとペルチィエ効果により熱電対接点が露点以下に冷却されて結露水が付着するが、通電を停止すると結露水の気化によって元の0μVに復元する。その復元過程のうち結露水の気化によってゆっくり上昇する平坦信号の始まる変曲点起電力Vdが、まさしく露点温度であり、つまり乾湿球の温度差に相当することから水ポテンシャルを計測でき、計測毎に湿接点に水滴を滴下して計測するRichard型サイクロメータと比較して、手間の省略と共に自動計測ができる画期的方法である。 The Pertier-type cyclometer developed by Spanner (1951) first offsets the Seebeck electromotive force of the thermocouple balanced with the temperature in the chamber to 0 μV, and then conversely, when a current is passed, the thermocouple contact becomes a dew point due to the Pertier effect. It is cooled below and dew condensation water adheres, but when the energization is stopped, it is restored to the original 0 μV by vaporization of the dew condensation water. In the restoration process, the turning point electromotive force Vd at which the flat signal that slowly rises due to the vaporization of condensed water starts is exactly the dew point temperature, that is, the water potential can be measured because it corresponds to the temperature difference of the wet and dry bulbs. This is an epoch-making method that can automatically measure the temperature while saving time and effort as compared with the Richard type cyclometer that measures by dropping water droplets on the wet contact point.
しかし、ペルチィア型熱電対サイクロメータは原理的には確立された計測方法ではあるが、計測データに対する計測値を明確に自動的に読み取れない、冷却電流と冷却時間の適正な設定ができていない、温度補正式が明らかでない、検量線の検定が不明瞭であるため、ペルチィア型熱電対サイクロメータの測定精度向上と自動計測化を阻んでいた。 However, although the Peltier thermocouple cyclometer is an established measurement method in principle, it cannot clearly and automatically read the measured values for the measurement data, and the cooling current and cooling time cannot be set appropriately. Since the temperature correction formula is not clear and the calibration curve test is unclear, it has hindered the improvement of measurement accuracy and automatic measurement of the Peltier thermocouple cyclometer.
本発明は、これらの問題点を解決するため、アメリカ製の市販品を頼ることなく、ペルチィア型熱電対サイクロメータの計測器本体を最初から製作して、パソコンと熱電対センサに接続することにより、その計測特性を詳細に検討した。その結果、請求項1に記載した露点温度を示す変曲点起電力Vdの自動読み取りソフトの開発、請求項2に記載したセンサ毎の適正な冷却電流と冷却時間とを設定して計測したときのセンサ毎の温度補正式の導入、請求項3に記載したセンサ毎の25℃検量線の導入により、計測精度の向上や温度変動の激しい現場での自動計測を可能にした。また、請求項4に記載した葉用アタッチメントと請求項5に記載した土壌用アタッチメントによって、測定資料を現場から採取して来るのではなく、測定資料にセンサを押し付けてそのままの状態in situで計測することが可能となり、蒸気圧平衡の時間短縮と非破壊計測を実現した。 In order to solve these problems, the present invention manufactures a measuring instrument body of a Peltier type thermocouple cyclometer from the beginning without relying on a commercially available product made in the United States, and connects it to a personal computer and a thermocouple sensor. , The measurement characteristics were examined in detail. As a result, when the development of the automatic reading software of the turning point electromotive force Vd indicating the dew point temperature described in claim 1 and the appropriate cooling current and cooling time for each sensor described in claim 2 are set and measured. the introduction of each of the sensor temperature correction formula, the introduction of 25 ° C. calibration curve of each sensor according to claim 3, allowing the automatic measurement of the intense field of measurement accuracy improved and temperature fluctuations. Also, the soil attachment according to claim 5 leaf attachment of claim 4, rather than the measured article is come collected from the field, measured as is in situ against the sensor to the measuring article It can be made, to achieve a time saving and non-destructive measurement of the vapor pressure equilibrium.
これにより、葉にセンサを挟むだけで作物葉の水ポテンシャルを、土壌にセンサを挿入するだけで土壌の水ポテンシャルをリアルタイムに直接デジタル表示できる温度変動の激しい現場計測を可能とした非破壊・連続・自動計測サイクロメータを実現した。 This enables non-destructive and continuous on-site measurement with severe temperature fluctuations, which enables direct digital display of the water potential of crop leaves by simply inserting a sensor between the leaves and the water potential of the soil in real time by simply inserting the sensor into the soil.・ Realized an automatic measurement cyclometer.
本発明は、計測器の測定精度と利便性に配慮して、(1)計測操作をパソコンによって完全自動化した、(2)露点温度を示す変曲点起電力Vdを合理的かつ自動的に読み取るパソコン用プログラムソフトを開発した、(3)温度変化のある現場計測が出来るように、25℃換算起電力V25を求めるセンサ毎の温度補正式を作成した、(4)これまで湿接点は十分結露すれば良いと適当に扱われてきた冷却電流と冷却時間を、センサ毎の適正値を設定して計測することにより再現性を確保した、(5)熱電対センサの凹溝チャンバーの溝深さを2mm以下と浅くしてチャンバー容量を小さくし、熱電対センサを測定対象に直接密着させて蒸気圧平衡時間を短くすると共に、葉を切断することなく、土壌を採取することなく、そのままの状態での計測を可能にした、(6)事前に求められたセンサ毎の25℃検量線からパソコンが水ポテンシャル値を直接算出して表示するので、リアルタイムな作物や土壌の水ポテンシャルを把握できるようになった。 In consideration of the measurement accuracy and convenience of the measuring instrument, the present invention reasonably and automatically reads (1) the measurement operation is fully automated by a personal computer, and (2) the turning point electromotive force Vd indicating the dew point temperature is read. We have developed program software for personal computers, (3) created a temperature compensation formula for each sensor that obtains an electromotive force V 25 converted to 25 ° C so that on-site measurement with temperature changes can be performed, and (4) wet contacts are sufficient so far. Reproducibility was ensured by setting appropriate values for each sensor and measuring the cooling current and cooling time, which had been appropriately treated as dew condensation. (5) Groove depth of the concave groove chamber of the thermocouple sensor The chamber capacity is reduced to 2 mm or less, the thermocouple sensor is brought into direct contact with the measurement target to shorten the vapor pressure equilibrium time, and the leaves are not cut and the soil is not collected. It enables measurement in the state. (6) Since the personal computer directly calculates and displays the water potential value from the 25 ° C calibration line for each sensor obtained in advance, it is possible to grasp the water potential of crops and soil in real time. It became so.
これまで研究論文で報告された自動計測サイクロメータは、真の変曲点起電力Vdを読み取るのではなく、通電停止後の一定時間後の2.4秒後や5秒後の熱電対起電力値Vを簡便に読み取っていたので、不合理であるばかりでなく非常に計測精度を悪くした。本特許では、請求項1に示すように開発したパソコン用自動読み取り解析ソフトによって真の変曲点起電力Vdを読み取っているので、正確な水ポテンシャル値が算出でき、再現性のある高精度な自動計測ができるようになった。 The automatic measurement cyclometers reported so far in research papers do not read the true inflection point electromotive force Vd, but the thermocouple electromotive force 2.4 seconds or 5 seconds after a certain period of time after the power is stopped. Since the value V was easily read, not only was it unreasonable, but the measurement accuracy was extremely poor. In this patent, since the true inflection point electromotive force Vd is read by the automatic reading analysis software for personal computers developed as shown in claim 1, an accurate water potential value can be calculated, and the water potential value is reproducible and highly accurate. Automatic measurement is now possible.
これまでの温度補正式に対する多くの論文は、温度計測範囲が限定的な直線回帰式が報告されたが、広範囲な温度範囲に対する温度補正式は請求項2に従って求めたところ2次曲線回帰式で相関された。このように従来結果と異なるのは、請求項1での変曲点起電力Vdの読み取りが正確になったためと考える。 So far, many papers relative to the temperature correction formula is the temperature measurement range is reported limiting linear regression equation, a wide range of temperature correction formula for temperature range quadratic regression equation was determined accordingly to claim 2 Correlated with. It is considered that the reason why the result is different from the conventional result is that the reading of the inflection point electromotive force Vd in claim 1 is accurate.
これまでの検量線は、0.05モル、0.1モル、0.3モル、0.5モル、1モル濃度の5種類のNaCl溶液を使用して相関した直線回帰式が提案されてきたが、本発明で行った検量線は、蒸留水、0.01モル、0.02モル、0.03モル、0.05モル、0.07モル、0.1モル、0.2モル、0.3モル、0.5モル、0.7モル、1モル、1.5モル、2モルの14種類の広範な濃度のNaCl溶液を使用して回帰したもので、計測された25℃変曲点起電力Vd25と既知の25℃浸透圧Ψ25との関係を相関したところ、請求項3に記載したようにセンサ毎に固有な25℃検量線が得られた。これも従来にない新しい知見である。 For the calibration lines so far, a linear regression equation correlated using five kinds of NaCl solutions having a concentration of 0.05 mol, 0.1 mol, 0.3 mol, 0.5 mol, and 1 mol has been proposed. However, the calibration lines performed in the present invention are distilled water, 0.01 mol, 0.02 mol, 0.03 mol, 0.05 mol, 0.07 mol, 0.1 mol, 0.2 mol, 0. .3 mol, 0.5 mol, 0.7 mol, 1 mol, 1.5 mol, 2 mol, relapsed using 14 broad concentrations of NaCl solution, measured 25 ° C. variation It was correlated relationship between TenOkoshi power Vd 25 and the known 25 ° C. osmolality [psi 25, 25 ° C. calibration curve specific to each sensor as described in claim 3 is obtained, et al. This is also a new finding that has never existed before.
これまでの市販計測器において蒸気圧平衡が長時間かかったのは、大きな容器の中に測定対象の土壌やカット葉を詰めて計測していたが、本特許では請求項4および請求項5のアタッチメントを用いて、小さな凹溝チャンバーを持つ熱電対センサを測定対象に直接押し付けて計測するため、チャンバー内容積が小さいので蒸気圧平衡時間が短くなり、かつ非破壊な計測が可能となった。応答性の速いリアルタイムな計測ができるようになった。 The reason why the vapor pressure equilibrium took a long time in the conventional commercially available measuring instruments was that the soil and cut leaves to be measured were packed in a large container for measurement, but in this patent, claims 4 and 5 Since the thermocouple sensor with a small concave groove chamber is directly pressed against the measurement target using the attachment for measurement, the vapor pressure equilibrium time is shortened because the internal volume of the chamber is small, and non-destructive measurement is possible. Real-time measurement with fast responsiveness has become possible .
更に、請求項1に記載される真の変曲点起電力Vdを読み取るパソコン用自動解析ソフトについて詳細に説明する。ペルティエ型熱電対サイクロメータの測定原理は、測定サンプルの水蒸気圧と平衡させた熱電対センサのチャンバー内の湿接点の熱電対起電力をオフセットして0μVに合わせて、次にこの湿接点の熱電対に逆電流を流してペルティエ効果によって湿接点を露点以下に冷却して結露させ、通電停止後の湿接点の熱電対起電力Vの変動から露点温度を検知して、その相対湿度から水ポテンシャルを演算して求める。 Further, the automatic analysis software for a personal computer that reads the true inflection point electromotive force Vd according to claim 1 will be described in detail. The measurement principle of the Peltier thermocouple cyclometer is to offset the thermocouple electromotive force of the wet contact in the chamber of the thermocouple sensor balanced with the water vapor pressure of the measurement sample to 0 μV, and then adjust the thermocouple of this wet contact. A reverse current is passed through the pair to cool the wet contact below the dew point by the Peltier effect to cause dew condensation, the dew point temperature is detected from the fluctuation of the thermocouple electromotive force V of the wet contact after the energization is stopped, and the water potential is detected from the relative humidity. Is calculated and calculated.
つまり、チャンバー内の熱電対に逆電流を流すことで生ずるペルチィエ効果が、熱電対接点を露点以下に冷却してチャンバー内の空気中の水滴を凝縮し、通電を止めると水滴は気化して冷却以前の温度に復元する。この復元過程の起電力を記録すると、結露水の気化過程と従前の気温への復元過程とは時間的勾配が明らかに異なり、通電停止に伴う電圧上昇はオーバーシュートして急激に上昇したのち、結露水の気化過程における湿接点起電力変動は緩慢な平坦信号を示し、そののち湿接点基部の参照接点からの熱流入によって冷却以前の0μVに復元する。その平坦信号の開始点が露点温度であることから、この変曲点起電力Vdを注意深く読み取り、この露点温度から相対湿度を求めて水ポテンシャルを算出する。 In other words, the Pertier effect caused by passing a reverse current through the thermocouple in the chamber cools the thermocouple contact below the dew point and condenses the water droplets in the air inside the chamber, and when the energization is stopped, the water droplets evaporate and cool. Restore to the previous temperature. When the electromotive force of this restoration process is recorded, the time gradient is clearly different between the vaporization process of the condensed water and the restoration process to the previous temperature, and the voltage rise due to the power stop overshoots and then rises sharply. The fluctuation of the wet contact electromotive force in the process of vaporizing the condensed water shows a slow flat signal, and then it is restored to 0 μV before cooling by the heat inflow from the reference contact at the base of the wet contact. Since the starting point of the flat signal is the dew point temperature, the inflection point electromotive force Vd is carefully read, and the relative humidity is obtained from this dew point temperature to calculate the water potential.
しかし、この変曲点の正確な読み取りは、従来はアナログ記録紙上で物差しを当てて読みとる煩雑な作業が必要であった。つまり平坦信号の直線部分に定規を当てて、曲線から直線へ遊離する点を注意深く読み取っていたが、測定者による読み取り誤差があり、直接水ポテンシャルを瞬時に表示できなかった。更に、従来のアナログ計測器では、同じセンサで同濃度の溶液に対して繰り返し計測を行っても、通電停止後の様相は全く異なり、変曲点起電力Vdも全く異なった。熱電対センサに対する冷却時間は、時間設定が曖昧になったため再現性を悪くしたようだ。再現性を向上させるためには適正な冷却電流と冷却時間を固定して計測する必要がある。 However, accurate reading of this inflection point has conventionally required complicated work of reading by measuring with a measuring rod on analog recording paper. In other words, a ruler was applied to the straight line part of the flat signal, and the point where the curve was separated from the straight line was carefully read, but there was a reading error by the measurer, and the water potential could not be displayed directly. Further, in the conventional analog measuring instrument, even if the same sensor is used to repeatedly measure the solution of the same concentration, the appearance after the energization is stopped is completely different, and the inflection point electromotive force Vd is also completely different. The cooling time for the thermocouple sensor seems to have deteriorated in reproducibility due to the ambiguous time setting . In order to improve reproducibility, it is necessary to fix and measure the appropriate cooling current and cooling time.
新しく製作したペルチィエ型熱電対サイクロメータを用いて、冷却電流と冷却時間を適正値に固定して計測した5千以上の生データを検証した結果、
冷却通電停止後の湿接点の熱電対起電力Vの変動を微小時間Δt秒毎にV 1 、V 2 、V 3 、V 4 、・・・・Vn,Vn +1 、Vn +2 、・・・・とデジタル記録されるとき、Δt秒毎の熱電対起電力Vの時間差分ΔV/ΔtをΔVn=Vn―Vn +1 と定義し、Δt秒毎の二階時間差分のΔ2V/Δt2をΔΔVn=ΔVn−ΔVn +1 と定義するとき、適正冷却時での変曲点起電力は最初にΔ2V/Δt2≧0となるV値であり、過冷却時での変曲点起電力は最初にΔV/Δt≧0となるリバウンドV値であり、全体として両者の早い時刻でのV値、または同時刻でのV値を変曲点起電力Vdとして採用する自動解析プログラムソフトを作成したので、自動読み取りできるようになった。
As a result of verifying more than 5,000 raw data measured by fixing the cooling current and cooling time to appropriate values using a newly manufactured Peltier thermocouple cyclometer.
The fluctuation of the thermoelectric electromotive force V of the wet contact after the cooling energization is stopped is changed every minute time Δt seconds V 1 , V 2 , V 3 , V 4 , ... Vn, Vn + 1 , Vn +2 , ... when ... and digitally recorded, the time difference [delta] V / delta] t of the thermoelectric TaiOkoshi power V of each delta] t seconds is defined as ΔVn = Vn-Vn +1, Δt seconds every second order time differential Δ 2 V / Δt 2 When is defined as ΔΔVn = ΔVn−ΔVn + 1 , the turning point electromotive force at the time of proper cooling is the V value at which Δ 2 V / Δt 2 ≧ 0 first, and the turning point electromotive force at the time of overcooling. The power is the rebound V value at which ΔV / Δt ≧ 0 first, and as a whole, automatic analysis program software that adopts the V value at the earlier time or the V value at the same time as the turning point electromotive force Vd is used. Now that you have created, it was Tsu name so that it can be read automatically.
熱電対サイクロメータ法は、計測中の周辺温度の変動に伴う誤差により測定精度が疑問視され、現地測定は不可能とされてきたが、変曲点起電力Vdは通電停止後1秒以内に存在し、通常設定される冷却時間の15秒を合算しても16秒で計測は終了する。そのため、1回の計測中の気温変動の影響はほとんど無視できる。 In the thermocouple cyclometer method, the measurement accuracy has been questioned due to the error caused by the fluctuation of the ambient temperature during measurement, and it has been considered impossible to perform on-site measurement. However, the turning point electromotive force Vd is within 1 second after the energization is stopped. Even if the existing cooling time of 15 seconds, which is normally set, is added up, the measurement is completed in 16 seconds. Therefore, the influence of temperature fluctuation during one measurement can be almost ignored.
本発明の最終目標は、誰でも簡単に作物体や土壌の水ポテンシャルを高精度かつ迅速に現場計測できる計測器を提供することにある。そのため、請求項4および請求項5に記載される葉用アタッチメントと土壌葉アタッチメントを利用し、熱電対センサを葉に挟むだけで、または熱電対センサを土壌に差し込むだけで、葉や土壌の水ポテンシャルの非破壊計測を実現した。高糖度トマトや高糖度メロンを栽培する圃場での基礎データを収集することにより、データに基づく合理的栽培技術を確立して、付加価値のある果菜類生産による経済的に有益な農業を展開する。 The ultimate goal of the present invention is to provide a measuring instrument that allows anyone to easily measure the water potential of a crop or soil in the field with high accuracy and speed. Therefore, by using the leaf attachment and soil leaf attachment according to claims 4 and 5, simply sandwiching the thermocouple sensor between the leaves or inserting the thermocouple sensor into the soil is sufficient to water the leaves and soil. It was realized a non-destructive measurement of potential. By collecting basic data in fields where high sugar content tomatoes and high sugar content melons are cultivated, we will establish rational cultivation techniques based on the data and develop economically beneficial agriculture by producing value-added fruits and vegetables . To.
その目標達成のためには、パソコン(マイコン)によって一連の複雑な計測操作を自動で行い、請求項1に記載した新たに開発した自動読み取り解析プログラムソフトによって、自動記録された湿接点のデジタル起電力データから瞬時かつ正確に読み取った変曲点起電力Vdと、乾接点の温度Tと、事前に求められた25℃検量線から、水ポテンシャル(水ストレス)Ψ25を素早く算出して直接デジタル表示できる非破壊・連続・自動計測できるサイクロメータがどうしても必要であった。請求項2および請求項3に記載された温度補正式や25℃検量線式の導入は、高精度な水ポテンシャル計測を得ることができるようになった。 In order to achieve that goal, a series of complicated measurement operations are automatically performed by a personal computer (microcomputer), and the newly developed automatic reading analysis program software described in claim 1 automatically records the wet contact digitally. The water potential (water stress) Ψ 25 is quickly calculated from the turning point electromotive force Vd read instantly and accurately from the power data, the temperature T of the dry contact, and the 25 ° C calibration curve obtained in advance, and is directly digitalized. A non-destructive, continuous, and automatic measurement cyclometer that can be displayed was absolutely necessary. The introduction of the temperature compensation type and the 25 ° C. calibration curve type according to claims 2 and 3 has made it possible to obtain highly accurate water potential measurement.
図1は、計測点が1点である1チャンネル用ペルチィア型熱電対サイクロメータの概要図であるが、サイクロメータ計測器本体3と、熱電対センサ5と、パソコン1とで構成され、それぞれをセンサ接続ケーブル4と、通信用USBケーブル2によって結ばれている。多数点を同時に計測できる多チャンネル用ペルチィア型熱電対サイクロメータは更にスキャナ回路を積載しており、既に8チャンネル用熱電対サイクロメータを完成するに至ったが、本発明では単純な1チャンネル用について説明する。 FIG. 1 is a schematic view of a 1-channel Peltier thermocouple cyclometer having one measurement point. It is composed of a cyclometer measuring instrument main body 3, a thermocouple sensor 5, and a personal computer 1, each of which is composed of a cyclometer measuring instrument main body 3. It is connected by the sensor connection cable 4 and the communication USB cable 2. The multi-channel thermocouple cyclometer that can measure a large number of points at the same time is further loaded with a scanner circuit, and the thermocouple cyclometer for 8 channels has already been completed. However, in the present invention, a simple one-channel thermocouple is used. explain.
サイクロメータ計測器本体3は、μコントローラー、D/Aコンバーター、数十ビットのΣΔA/Dコンバーター等の半導体チップを使用して、ヘッドアンプ増幅回路、微小電圧測定回路、定電流発生回路、熱電対測温回路等を構成している。 The cyclometer measuring instrument main body 3 uses a semiconductor chip such as a μ controller, a D / A converter, and a tens of bits ΣΔA / D converter, and uses a head amplifier amplifier circuit, a minute voltage measurement circuit, a constant current generation circuit, and a thermocouple. It constitutes a temperature measurement circuit, etc.
図2の熱電対センサ5は、凹型チャンバー内に気温測定用のT型乾接点熱電対9と露点計測用のE型湿接点熱電対8の2つの熱電対接点を内蔵している。 The thermocouple sensor 5 of FIG. 2 has two thermocouple contacts, a T-type dry contact thermocouple 9 for temperature measurement and an E-type wet contact thermocouple 8 for dew point measurement, built in the concave chamber.
図1のパソコン1は、サイクロメータ計測器本体3を介して熱電対センサ5を自動計測操作しており、T型乾接点熱電対9の気温と露点計測用のE型湿接点熱電対8の起電力変動をデジタル自動記録すると共に、露点計測用のE型湿接点熱電対8の起電力変動に対して解析プログラムソフトによって露点温度を示す変曲点起電力Vdを自動読み取りする。 The personal computer 1 of FIG. 1 automatically measures and operates the thermocouple sensor 5 via the cyclometer measuring instrument main body 3, and of the E-type wet contact thermocouple 8 for measuring the temperature and dew point of the T-type dry contact thermocouple 9. The electromotive force fluctuation is automatically recorded digitally, and the turning point electromotive force Vd indicating the dew point temperature is automatically read by the analysis program software for the electromotive force fluctuation of the E-type wet contact thermocouple 8 for dew point measurement.
非破壊、連続、自動計測するペルチィア型熱電対サイクロメータは、凹型チャンバー内のT型乾接点熱電対9による気温の常時デジタル計測記録、E型湿接点熱電対8における起電力の0点調整、E型湿接点熱電対8への通電によるペルチィエ効果による露点温度以下への冷却、E型湿接点熱電対8の結露後の通電停止、結露水が気化し始めて冷却以前の温度に復元する復元過程のE型湿接点熱電対8の起電力変化のデジタル記録、E型湿接点熱電対8のデジタル記録データ上における請求項1に記載する変曲点起電力Vdの自動読み取り、その変曲点起電力VdとT型乾接点熱電対9の測定気温Tとから請求項2に記載する温度補正式によって換算された25℃起電力V25と、請求項3に記載する25℃検量線から演算された25℃水ポテンシャル値Ψ25 のデジタル表示という、この一連の煩雑な計測手順、デジタル記録、解析・演算・表示をパソコン1(マイコン)制御操作により簡潔に処理された。更に1回の計測時間を数十秒以下の迅速さで行うことによって、1回の計測中の周辺温度の変動による測定誤差を小さく出来た。本願の構成は、請求項1に記載の露点温度を示す変曲点起電力Vdの自動読み取り、請求項2に記載の温度補正式、請求項3に記載の25℃検量線から、最終目的である測定試料10の水ポテンシャル値Ψ25を直接算出表示することを特徴としている。 The non-destructive, continuous, and automatic measurement Peltier type thermocouple cyclometer is a constant digital measurement record of the temperature by the T-type dry contact thermocouple 9 in the concave chamber, and 0 point adjustment of the electromotive force in the E type wet contact thermocouple 8. Cooling below the dew point temperature due to the Pertier effect by energizing the E-type wet contact thermocouple 8, stopping the energization of the E-type wet contact thermocouple 8 after dew condensation, restoration process in which the condensed water begins to vaporize and restores to the temperature before cooling Digital recording of the electromotive force change of the E-type wet contact thermocouple 8 and automatic reading of the electromotive force Vd at the turning point according to claim 1 on the digital recording data of the E-type wet contact thermocouple 8; Calculated from the 25 ° C electromotive force V 25 converted by the temperature correction formula according to claim 2 from the power Vd and the measured temperature T of the T-type dry contact thermocouple 9 and the 25 ° C calibration line according to claim 3. that 25 ° C. water potential values [psi 25 of the digital display has, this series of complicated measuring procedure, digital recording, treated briefly with the analysis and calculation and display personal computer 1 (microcomputer) controls operations. Furthermore, by performing one measurement time as quickly as several tens of seconds or less, it was possible to reduce the measurement error due to fluctuations in the ambient temperature during one measurement . The configuration of the present application is, for the final purpose, from the automatic reading of the turning point electromotive force Vd indicating the dew point temperature according to claim 1, the temperature correction formula according to claim 2, and the 25 ° C. calibration curve according to claim 3. It is characterized in that the water potential value Ψ 25 of a certain measurement sample 10 is directly calculated and displayed.
図2は水ポテンシャル計測用の熱電対センサ5であり、外径8.8mm、長さ15mmの円形テフロン棒7をベースにして、先端に内径5.2mm、深さ1mmの溝をカットして小さな円柱形の凹溝チャンバーを作製する。更に、円柱形凹溝内に丸穴を3か所あけるが、凹溝の中心に露点計測用のE型湿接点熱電対8の接点を配置するため、時計の三時方向と九時方向に、丸穴の中心間距離を3.5mmとしたΦ1.5mm丸穴を2つ、その六時方向に気温計測用のT型乾接点熱電対9を設置するためのΦ1.5mm丸穴を1つドリルで開ける。円形テフロン棒7の外周は、長さ23mm、内径9mm、外径10mmのステンレス製円筒保護管6を、先端を揃えてエポキシ接着材19で固定する。(なお、テフロンはイー・アイ・デユポン・ドウ・ヌムール・アンド・カンパニーの登録商標である。) FIG. 2 shows a thermocouple sensor 5 for measuring water potential. Based on a circular Teflon rod 7 having an outer diameter of 8.8 mm and a length of 15 mm, a groove having an inner diameter of 5.2 mm and a depth of 1 mm is cut at the tip. Create a small cylindrical concave groove chamber. In addition, three round holes are drilled in the cylindrical concave groove, but in order to arrange the contact of the E-type wet contact thermocouple 8 for dew point measurement in the center of the concave groove, it is in the 3 o'clock direction and the 9 o'clock direction of the watch. , Two Φ1.5 mm round holes with a center-to-center distance of 3.5 mm, and one Φ1.5 mm round hole for installing a T-type dry contact thermocouple 9 for temperature measurement at 6 o'clock. Open with a drill. On the outer circumference of the circular Teflon rod 7, a stainless steel cylindrical protective tube 6 having a length of 23 mm, an inner diameter of 9 mm, and an outer diameter of 10 mm is fixed with an epoxy adhesive 19 with the tips aligned. (Teflon is a registered trademark of EI Deyupon Do Nemours & Company.)
露点計測用のE型湿接点熱電対8は、三時方向と九時方向の2つの丸穴内に、長さ20mm、Φ1mmの熱電対基部銅線18を挿入して外周をエポキシ接着剤19で固定するが、その2本の熱電対基部銅線18の上端が凹溝チャンバー内に突出しないように固定する。そして、それぞれの熱電対基部銅線18の上端面にΦ25μmクロメル線20とΦ25μmコンスタンタン線21とを溶接してのち、更にΦ25μmクロメル線20とΦ25μmコンスタンタン線21の極細線同士を溶接して露点計測用のE型湿接点熱電対8を形成する。そのE型熱電対の接点高さは、凹溝深さ1mmの中央にするため約0.5mmとする。2本のE型湿接点熱電対の基部銅線18の下方端には、長さ10mの0.3SQ(断面積約0.3mm2)2芯銅線シールド線22を接続する。 The E-type wet contact thermocouple 8 for measuring the dew point has a 20 mm long, Φ1 mm thermocouple base copper wire 18 inserted in two round holes in the 3 o'clock direction and the 9 o'clock direction, and the outer circumference is covered with an epoxy adhesive 19. It is fixed, but the upper ends of the two thermocouple base copper wires 18 are fixed so as not to protrude into the recessed groove chamber. Then, after welding the Φ25 μm chromel wire 20 and the Φ25 μm constantan wire 21 to the upper end surface of each thermocouple base copper wire 18, the ultrafine wires of the Φ25 μm chromel wire 20 and the Φ25 μm constantan wire 21 are further welded to measure the dew point. E-type wet contact thermocouple 8 for use is formed. The contact height of the E-type thermocouple is set to about 0.5 mm in order to center the concave groove depth of 1 mm. A 0.3 SQ (cross-sectional area of about 0.3 mm 2 ) 2-core copper wire shielded wire 22 having a length of 10 m is connected to the lower end of the base copper wire 18 of the two E-type wet contact thermocouples.
Φ0.5mm銅線とΦ0.5mmコンスタンタン線との先端を半田付けした気温計測用のT型乾接点熱電対9は、六時方向に開けられたΦ1.5mm穴に挿入して、外周をエポキシ接着剤19で固定するが、先端のT型熱電対の裸接点は凹溝チャンバー表面にわずかに露出させて固定する。銅線とコンスタンタン線のT型熱電対の長さも10mとする。 The T-type dry contact thermocouple 9 for temperature measurement, in which the tips of the Φ0.5 mm copper wire and the Φ0.5 mm constantan wire are soldered, is inserted into the Φ1.5 mm hole opened at 6 o'clock, and the outer circumference is epoxy. It is fixed with the adhesive 19, but the bare contact of the T-type thermocouple at the tip is slightly exposed on the surface of the concave groove chamber and fixed. The length of the T-type thermocouple of the copper wire and the constantan wire is also 10 m.
センサ接続ケーブル4は、E型湿接点熱電対に接続する0.3SQ2芯銅線シールド線22と、T型乾接点熱電対を構成するΦ0.5mmの銅―コンスタンタン線を、それぞれ10m長さで切り揃え、所々を収縮チューブで留める。サイクロメータ計測器本体3に接続するコネクター23には、2芯銅線の2本、シールド線1本、銅―コンスタンタン線の各1本の合計5本が繋いである。 The sensor connection cable 4 consists of a 0.3SQ 2-core copper wire shielded wire 22 connected to an E-type wet contact thermocouple and a Φ0.5 mm copper-constantan wire constituting a T-type dry contact thermocouple, each having a length of 10 m. Cut and align and fasten in places with shrink tubes. A total of five connectors, two 2-core copper wires, one shielded wire, and one copper-constantan wire, are connected to the connector 23 connected to the cyclometer measuring instrument main body 3.
ペルチィア型熱電対サイクロメータの計測において一番重要な作業は、請求項1に記載したように、計測値として求める露点温度の正確な自動読み取りにある。 As described in claim 1, the most important task in the measurement of the Peltier thermocouple cyclometer is the accurate automatic reading of the dew point temperature obtained as the measured value.
ペルチィア型熱電対サイクロメータの計測では、凹型チャンバー内の気温と平衡した湿接点のゼーベック効果による熱電対起電力Vを最初オフセットして0μVとし、次に逆電流を流すとペルチィエ効果により冷却されて湿接点上に結露するが、結露後通電を停止すると、湿接点のマイナスの熱電対起電力Vの変動は、最初に通電停止によって急激に上昇し、次に結露水の気化によってゆっくり温度上昇する平坦信号を示し、次に参照接点からの熱の流入により最初のオフセット電圧0μVまで上昇する復元曲線を示す。 In the measurement of the Peltier thermocouple cyclometer, the thermocouple electromotive force V due to the Seebeck effect of the wet contact that is balanced with the temperature in the concave chamber is first offset to 0 μV, and then when a reverse current is applied, it is cooled by the Peltier effect. Condensation forms on the wet contacts, but when the energization is stopped after the dew condensation, the fluctuation of the negative thermocouple electromotive force V of the wet contacts first rises sharply due to the stop of energization, and then the temperature rises slowly due to the vaporization of the condensed water. A flat signal is shown, followed by a restoration curve where the initial offset voltage rises to 0 μV due to the inflow of heat from the reference contact.
この復元曲線のうち結露水の気化によってゆっくり上昇する平坦信号の始まる変曲点起電力Vdが、まさしく露点温度であり、つまり乾湿球の温度差に相当する。 In this restoration curve, the inflection point electromotive force Vd at which the flat signal that slowly rises due to the vaporization of condensed water starts is exactly the dew point temperature, that is, corresponds to the temperature difference of the wet and dry bulbs.
曲線の変曲点は、変化の勾配変動がない点で、数学的には二階微分Δ2V/Δt2=0の点であるが、これは熱電対接点が球形空間の中心にあり、接点上の結露水が周辺空気の全方位から吸熱して気化する理想状態の場合であって、直径5.2mm、深さ1mmの円柱空間の凹溝チャンバー内の中心に湿接点を置いている実際条件とは大きく異なる。 The inflection point of the curve is the point where the gradient of change does not change, and mathematically it is the point of the second-order differential Δ 2 V / Δt 2 = 0, but this is because the thermoelectric pair contact point is in the center of the spherical space and the contact point. In the ideal state where the above condensed water absorbs heat from all directions of the surrounding air and vaporizes, the wet contact is actually placed in the center of the concave groove chamber of a cylindrical space with a diameter of 5.2 mm and a depth of 1 mm. It is very different from the conditions.
本計測器では、実測する熱電対起電力Vの変動データから変曲点起電力Vdを合理的に見出すことが重要であり、冷却通電停止後のE型湿接点8のマイナスの熱電対起電力Vの変動を微小時間の0.1秒毎にデジタル記録するとき、図13およびず14の起電力Vの欄はV0.1、V0.2、V0.3、V0.4・・・・・と記載される。その0.1秒毎の時間差分ΔVの欄はΔV0.1=V0.1−V0.2、ΔV0.2=V0.2−V0.3、ΔV0.3=V0.3−V0.4、・・・・と演算され、0.1秒毎の二階時間差分のΔΔVの欄はΔΔV0.1=ΔV0.1−ΔV0.2、ΔΔV0.2=ΔV0.2−ΔV0.3、ΔΔV0.3=ΔV0.3−ΔV0.4、・・・・・と演算されていく。五千以上の多数の実測データを検討した結果、適正冷却時での変曲点起電力は最初にΔΔV≧0となるV値であり(図13)、過冷却時での変曲点起電力は最初にΔV≧0となるリバウンドV値である(図14)ことが見出され、全体として両者の早い時刻でのV値、または両者の同時刻でのV値を変曲点起電力Vdとして自動読み取りするパソコン用プログラムソフトを作成した。これにより、全ての計測データに対して露点温度を示す変曲点起電力Vdを正確に読み取ることができた。 In this instrument, it is important to reasonably find inflection point electromotive force Vd from variation data thermoelectric TaiOkoshi power V to be measured, a negative thermoelectric TaiOkoshi power cooling deenergized after the E-type wet contact 8 When the fluctuation of V is digitally recorded every 0.1 seconds of a minute time, the column of electromotive force V in FIGS. 13 and 14 is described as V 0.1 , V 0.2 , V 0.3 , V 0.4 .... .. The column of the time difference ΔV every 0.1 seconds is calculated as ΔV 0.1 = V 0.1 −V 0.2 , ΔV 0.2 = V 0.2 −V 0.3 , ΔV 0.3 = V 0.3 −V 0.4 , and so on. The column of ΔΔV of the second-order time difference every second is calculated as ΔΔV 0.1 = ΔV 0.1 −ΔV 0.2 , ΔΔV 0.2 = ΔV 0.2 −ΔV 0.3 , ΔΔV 0.3 = ΔV 0.3 − ΔV 0.4 , and so on. As a result of examining a large number of actually measured data of more than 5,000, the inflection point electromotive force at the time of proper cooling is the V value at which ΔΔV ≧ 0 at first (Fig. 13), and the inflection point electromotive force at the time of overcooling. Is the rebound V value at which ΔV ≧ 0 at first (Fig. 14), and as a whole, the V value at the earlier time of both or the V value at the same time of both is the inflection point electromotive force Vd. I created a program software for a personal computer that automatically reads as . As a result , the inflection point electromotive force Vd indicating the dew point temperature could be accurately read for all the measured data.
図13は、NaClの1モル溶液に対して冷却電流7mA、冷却時間15秒で湿接点を冷却したのち、通電停止後のE型湿接点熱電対8の起電力Vを0.1秒毎に表示したものであるが、図13のΔVはVの変化量であることから、一行目のVから二行目のVを差し引いた値を一行目のΔVとして記入し、図13のΔΔVはΔVの変化勾配であることから、一行目のΔVから二行目のΔVを差し引いた値を一行目のΔΔVとして記入し、その後の値は同様に逐次計算される。通常処理では、一行目から二行目を差し引いた値を二行目に前進差分として記入されるが、本発明では敢えて一行目に記入して後退差分とした理由は、求める計測値が平坦信号の開始点であるので、変化の開始点または変化勾配の開始点を読み取る為に、一行目に後退差分として記入した。その後、計測起電力Vから逐次ΔVとΔΔVの0.1秒毎の後退差分を全て算出して記入する。結果、図13ではΔVが正の0.000に変わる1.3秒後と、ΔΔVが正の0.033に変わる0.4秒後を変曲点と見なすが、全体として両者の早い時刻の0.4秒後の起電力−19.120μVを適正冷却時の変曲点起電力Vdとして読み取られ、その時のチャンバー内温度Tは13.8℃である。 In FIG. 13, after cooling the wet contact with a cooling current of 7 mA and a cooling time of 15 seconds with respect to a 1 mol solution of NaCl, the electromotive force V of the E-type wet contact thermocouple 8 after the energization is stopped is applied every 0.1 seconds. Although it is displayed, since ΔV in FIG. 13 is the amount of change in V, the value obtained by subtracting V in the second row from V in the first row is entered as ΔV in the first row, and ΔΔV in FIG. 13 is ΔV. Since it is the change gradient of, the value obtained by subtracting the ΔV of the second line from the ΔV of the first line is entered as the ΔΔV of the first line, and the subsequent values are similarly calculated sequentially. In normal processing, the value obtained by subtracting the second line from the first line is entered as the forward difference in the second line, but in the present invention, the reason why the value is intentionally entered in the first line and used as the backward difference is that the measured value to be obtained is a flat signal. Since it is the starting point of, in order to read the starting point of the change or the starting point of the change gradient, it is entered as the receding difference in the first line. After that, all the receding differences between ΔV and ΔΔV every 0.1 second are calculated and entered from the measured electromotive force V. As a result, in FIG. 13, 1.3 seconds after ΔV changes to positive 0.000 and 0.4 seconds after ΔΔV changes to positive 0.033 are regarded as inflection points, but as a whole, both are earlier in time. it is read electromotive force -19.120μV after 0.4 seconds as the variable KyokutenOkoshi power Vd during proper cooling, chamber temperature T at that time is 13.8 ° C..
図5は図13の冷却時間15秒、冷却電流7mAの適正冷却時におけるE型湿接点熱電対8の起電力変動を図示したもので、白丸で記した変曲点以降しばらく平坦信号を示す。 FIG. 5 illustrates the fluctuation of the electromotive force of the E-type wet contact thermocouple 8 at the time of proper cooling with a cooling time of 15 seconds and a cooling current of 7 mA in FIG. 13, and shows a flat signal for a while after the inflection point marked with a white circle.
図14はNaClの1モル溶液に対して冷却電流10mA、冷却時間15秒で湿接点を冷却したのち、通電停止後の湿接点熱電対の起電力Vを0.1秒毎に表示したものであるが、図13と同様に起電力V、ΔV、ΔΔVを演算処理すると、ΔVが正の0.073に変わる0.1秒後と、ΔΔVが正の0.449に変わる0.1秒後が変曲点と見なされ、全体として両者の同時刻0.1秒後の起電力−16.909μVを過冷却時の変曲点起電力Vdとして読み取られ、その時のチャンバー内温度Tは13.8℃である。 FIG. 14 shows the electromotive force V of the wet contact thermocouple after cooling the wet contact with a cooling current of 10 mA and a cooling time of 15 seconds for a 1 mol solution of NaCl every 0.1 seconds. However, when the electromotive forces V, ΔV, and ΔΔV are processed in the same manner as in FIG. 13, 0.1 seconds after ΔV changes to positive 0.073 and 0.1 seconds after ΔΔV changes to positive 0.449. is considered an inflection point, is read electromotive force -16.909μV of both at the same time 0.1 second after the whole variable KyokutenOkoshi power Vd during supercooling, the chamber temperature T at that time 13 It is 8.8 ° C.
なお、最高計測範囲とするNaCl−2モル溶液(25℃でー9.787MPa浸透圧)が計測できる7mA15秒を図7から適正冷却条件としたが、検量線は同一冷却条件で全て計測するので、濃度の薄い溶液に対しては当然過冷却になる。本発明は、その点を十分考慮して、適正冷却時も過冷却時でも適応できる計測値の自動読み取りパソコン用プログラムソフトを作成した。 In addition, 7mA 15 seconds, which can measure a NaCl-2 mol solution (-9,787 MPa osmotic pressure at 25 ° C), which is the maximum measurement range, was set as an appropriate cooling condition from FIG. 7, but since all the calibration curves are measured under the same cooling condition. Naturally, it will be supercooled for a solution with a low concentration. In the present invention, in consideration of this point, a program software for a personal computer that automatically reads measured values that can be applied to both proper cooling and supercooling has been created.
図6は図14の冷却時間15秒、冷却電流10mAの過冷却時における湿接点の起電力変動を図示したものであるが、通電停止後オーバーシュートして一段と上昇したリバウンド値が変曲点起電力Vdとなっており、白丸で記した変曲点以降しばらく平坦信号を示す。 FIG. 6 illustrates the fluctuation of the electromotive force of the wet contact during supercooling with a cooling time of 15 seconds and a cooling current of 10 mA in FIG. 14, but the rebound value that overshoots and rises further after the power supply is stopped causes an inflection point. The electric power is Vd, and a flat signal is shown for a while after the inflection point marked with a white circle.
図7はNaClの2モル溶液、1.5モル溶液、1モル溶液に対して、冷却時間を15秒に固定した場合の各冷却電流における25℃変曲点起電力Vd25を図示したものであるが、5.5mA以上の冷却電流を流さないと最高濃度のNaCl−2モル溶液(25℃で−9.787MPa浸透圧)は計測できない。3種類の溶液濃度に対する安定的な計測を得るためには、冷却時間15秒において6〜9mAの冷却電流が必要で、低濃度溶液における過冷却を少なくするため、適正冷却条件として冷却時間15秒、冷却電流7mAを採用した。 FIG. 7 illustrates the 25 ° C. turning point osmotic pressure Vd 25 at each cooling current when the cooling time is fixed at 15 seconds for a 2 mol solution, a 1.5 mol solution, and a 1 mol solution of NaCl. However, the maximum concentration of NaCl-2 mol solution (-9.787 MPa osmotic pressure at 25 ° C.) cannot be measured unless a cooling current of 5.5 mA or more is applied. In order to obtain stable measurements for the three types of solution concentrations, a cooling current of 6 to 9 mA is required at a cooling time of 15 seconds, and in order to reduce supercooling in low-concentration solutions, a cooling time of 15 seconds is an appropriate cooling condition. , A cooling current of 7 mA was adopted.
しかし、熱電対センサは同一仕様で製作するのであるが、図7はセンサ毎で様相が異なり、1モル溶液まで計測できるもの、1.5モル溶液まで計測できるもの、2モル溶液まで計測できるものが生じ、それぞれ計測限界の特性が異なる。Φ25μmのE型湿接点熱電対8の接点の大きさが微妙に異なるため生ずるものと推定するが、測定範囲が広く、かつ安定計測ができるセンサ構造を究明する必要がある。 However, although the thermocouple sensor is manufactured with the same specifications, the appearance of each sensor is different, and those that can measure up to 1 mol solution, those that can measure up to 1.5 mol solution, and those that can measure up to 2 mol solution. , And the characteristics of the measurement limit are different for each. It is presumed that this occurs because the contact size of the E-type wet contact thermocouple 8 with a diameter of 25 μm is slightly different, but it is necessary to investigate a sensor structure that has a wide measurement range and enables stable measurement.
図8はNaCl−1モル溶液(25℃で−4.644MPa浸透圧)において、冷却電流を7mAに固定した場合の各冷却時間と25℃変曲点起電力Vd25との関係を図示したものであるが、明らかに冷却時間が多いほど25℃変曲点起電力Vd25は小さくなり、冷却条件は湿接点が十分に露点温度以下に冷却されれば適当で良いという従来の考えは否定される。つまり、再現性を確保するためには常に同一冷却条件で計測する必要があり、請求項3に記載したように、冷却電流と冷却時間の設定値は固定して計測しなければならない。冷却時間は、図8より15秒を適正時間として採用した。 FIG. 8 illustrates the relationship between each cooling time and the 25 ° C. turning point electromotive force Vd 25 when the cooling current is fixed at 7 mA in a NaCl-1 mol solution (-4.644 MPa osmotic pressure at 25 ° C.). However, obviously, the longer the cooling time, the smaller the 25 ° C. turning point electromotive force Vd 25 , and the conventional idea that the cooling conditions should be appropriate if the wet contacts are sufficiently cooled below the dew point temperature is denied. To. That is, in order to ensure reproducibility, it is necessary to always measure under the same cooling conditions, and as described in claim 3, the set values of the cooling current and the cooling time must be fixed and measured. As the cooling time, 15 seconds was adopted as an appropriate time from FIG.
図9は冷却条件7mA15秒の場合の25℃検量線であり、蒸留水からNaCl−2モルまでの異なる濃度の14種類溶液の25℃浸透圧Ψ 25 (25℃におけるNaClのモル濃度毎の浸透圧は発表されており既知)に対する25℃変曲点起電力Vd25の関係を見たもので、請求項3に記載した検量線の作成法により25℃検量線Ψ 25 =f(V 25 2 )が得られる。この25℃検量線はセンサ毎に異なるので、センサ毎に事前に求めておく必要がある。 Figure 9 is a 25 ° C. calibration curve in the case of cooling conditions 7mA15 seconds, penetration of distilled water 25 ° C. osmotic pressure [psi 25 14 type solutions of different concentrations of up to NaCl-2 moles (per mole concentration of NaCl at 25 ° C. pressure as viewed the relationship 25 ° C. HenkyokutenOkoshi power Vd 25 to known) have been published, the generating method of a calibration curve according to claim 3 25 ° C. calibration curve Ψ 25 = f (V 25 2 ) is obtained, et al. Since this 25 ° C. calibration curve is different for each sensor, it is necessary to obtain it in advance for each sensor .
従来の検量線は、0.05モル、0.1モル、0.3モル、0.5モル、1モル濃度の5種類のNaCl溶液を使用して相関した直線回帰式が提案されてきた。確かに、図9でもNaCl−1モル濃度までは浸透圧に対して直線的に25℃変曲点起電力Vd25が低下していくが、NaCl−1.5モル濃度、2モル濃度での25℃変曲点起電力Vd25は低下度合が緩慢となり、NaCl−1.5モル濃度、2モル濃度を含めた全体としては2次曲線式で回帰される。これは、計測適用範囲を広げたため2次回帰曲線式になった。ちなみに、図9のセンサでは2.2モル濃度NaCl溶液(25℃浸透圧―10.887MPa)の計測値は白丸となって計測不可の計測外となり、その2モル濃度NaCl溶液までの計測域の検量線は次式で示される。Ψは勿論25℃での水ポテンシャルΨ 25 である。
Ψ=−0.004428・V25 2+0.1254・V25+0.275
ここで、Ψ:水ポテンシャル(MPa)、V25:25℃変換変曲点起電力(μV)
For the conventional calibration curve, a linear regression equation correlated using five kinds of NaCl solutions having a concentration of 0.05 mol, 0.1 mol, 0.3 mol, 0.5 mol, and 1 mol has been proposed. It is true that even in FIG. 9, the 25 ° C. turning point electromotive force Vd 25 decreases linearly with respect to the osmotic pressure up to the NaCl-1 molar concentration, but at the NaCl-1.5 molar concentration and the 2 molar concentration. The degree of decrease of the 25 ° C. turning point osmotic pressure Vd 25 becomes slow, and the whole is returned by a quadratic curve formula including the NaCl −1.5 molar concentration and the 2 molar concentration. This is a quadratic regression curve formula because the measurement application range is expanded. Incidentally, the measurement value of 2.2 molar NaCl solution in the sensor of FIG. 9 (25 ° C. osmotic -10.887MPa) becomes a measurement outside disabled measurement becomes white circle, the measurement range of up to the 2 molar NaCl solution The calibration curve is expressed by the following equation. Ψ is, of course, the water potential Ψ 25 at 25 ° C.
Ψ = -0.004428 · V 25 2 +0.1254 · V 25 +0.275
Here, Ψ: water potential (MPa), V 25 : 25 ° C conversion inflection point electromotive force (μV)
図10は、1モル濃度のNaCl溶液に、センサ先端にある熱電対を内蔵するチャンバーを密着させて、気温変動のある現場で終日連続自動計測したが、計測値の変曲点起電力Vdはチャンバー内の乾接点の計測気温Tの2次回帰式で相関され、T=25℃を代入すると25℃変曲点起電力はV25=−19.910μVを得る。検量線はNaClの各濃度別溶液の25℃浸透圧で検定されるので、同様に25℃変曲点起電力Vd25を基準とすると、その変曲点起電力VdとV25との比Vd/V25は、図11のように温度Tに依存し、2次回帰式Vd/V25=f(T2)で相関され、本回帰式を温度補正式と呼ぶ。しかし、同一仕様でセンサは製作されるが、温度補正式Vd/V25=f(T2)はセンサ毎に微妙に異なるので、センサ毎に求める必要がある。そして、1モル濃度NaCl溶液の温度補正式を代表式として採用した。図11のセンサの温度補正式は次式となる。
Vd/V25=0.000453・T2+0.0121・T+0.4136
In FIG. 10, the chamber containing the thermocouple at the tip of the sensor was brought into close contact with a 1-molar NaCl solution, and continuous automatic measurement was performed throughout the day at a site where the temperature fluctuated. Correlated by the quadratic regression equation of the measured temperature T of the dry contact in the chamber, when T = 25 ° C is substituted, the 25 ° C inflection point electromotive force is V 25 = -19.910 μV. Since the calibration curve is tested by the osmotic pressure of each concentration of NaCl at 25 ° C., similarly, based on the 25 ° C. turning point electromotive force Vd 25 , the ratio Vd of the turning point electromotive force Vd to V 25 is used. As shown in FIG. 11, / V 25 depends on the temperature T and is correlated with the quadratic regression equation Vd / V 25 = f (T 2 ), and this regression equation is called a temperature correction equation. However, although sensors are manufactured with the same specifications, the temperature compensation type Vd / V 25 = f (T 2 ) is slightly different for each sensor, so it is necessary to obtain it for each sensor. Then, the temperature correction formula of the 1 molar concentration NaCl solution was adopted as a representative formula. The temperature compensation formula for the sensor in FIG. 11 is as follows.
Vd / V 25 = 0.000453 · T 2 + 0.0121 · T + 0.4136
このことから、請求項2に記載したように湿接点の変曲点起電力Vdと乾接点の気温Tを、温度補正式の両項を取り替えて変換したV25=Vd/f(T2)に代入して25℃変曲点起電力Vd25を算出し、更にセンサ毎に事前に求められた25℃検量線Ψ 25 =f(V 25 2 )に代入して、最終目的である測定試料の水ポテンシャル値(浸透圧値)Ψ25を求める。これにより、気温変動の激しい現場計測が可能となった。
ちなみに、図11のセンサの温度補正は次式を用いる。
V25=Vd/(0.000453・T2+0.0121・T+0.4136)
From this, as described in claim 2, V 25 = Vd / f (T 2 ) obtained by converting the turning point electromotive force Vd of the wet contact and the temperature T of the dry contact by exchanging both terms of the temperature correction formula. by substituting calculate the 25 ° C. HenkyokutenOkoshi power Vd 25 to, is substituted further 25 ° C. calibration curve previously obtained for each sensor Ψ 25 = f (V 25 2 ), a measurement sample is the final purpose Ru determine the water potential value (osmotic value) Ψ 25. This has made it possible to perform on-site measurement with drastic temperature fluctuations.
Incidentally, the following equation is used for the temperature correction of the sensor in FIG.
V 25 = Vd / (0.000453 · T 2 + 0.0121 · T + 0.4136)
図12は、図3および請求項4に記載した葉用アタッチメントに内挿した熱電対センサ5をナスの葉に装着して、非破壊・連続・自動・現場計測したもので、50日連続測定の内の最初の一週間分のナス葉の水ポテンシャル変動を図示した。その変動は天候条件に大きく影響されるが、10分間隔での計測は葉の水ポテンシャル変動を良く追尾している。 FIG. 12 shows a non-destructive, continuous, automatic, and on-site measurement in which the thermocouple sensor 5 inserted in the leaf attachment described in FIGS. 3 and 4 is attached to an eggplant leaf, and is measured continuously for 50 days. The water potential fluctuations of eggplant leaves for the first week of the above are illustrated. The fluctuation is greatly affected by the weather conditions, but the measurement at 10-minute intervals closely tracks the fluctuation of the water potential of the leaves.
図3は、作物葉11の葉裏に熱電対センサ5を密着させて取り付けるための葉用アタッチメントで、洗濯バサミ12の下面に内径10.1mm、外径12mm、長さ35mmのアルミ収納管14がエポキシ接着材19で固定されている。作物葉11の水ポテンシャルは、このアルミ収納管14の中に、外径10mm、長さ23mmの熱電対センサ5を内挿してビニルテープ等で固定して計測する。作物葉11の装着は、作物葉11の物理的ダメージを考慮すると、洗濯バサミ12のバネ13の力程度で挟むのが良く、爪楊枝で作ったロック棒15で固定して計測する。 FIG. 3 shows a leaf attachment for attaching the thermocouple sensor 5 to the back of the leaf of the crop leaf 11 in close contact with the aluminum storage tube 14 having an inner diameter of 10.1 mm, an outer diameter of 12 mm, and a length of 35 mm on the lower surface of the clothespin 12. Is fixed with the epoxy adhesive 19. The water potential of the crop leaf 11 is measured by inserting a thermocouple sensor 5 having an outer diameter of 10 mm and a length of 23 mm into the aluminum storage tube 14 and fixing it with vinyl tape or the like. Considering the physical damage of the crop leaf 11, the crop leaf 11 should be sandwiched by the force of the spring 13 of the clothespin 12, and is fixed by the lock rod 15 made of a toothpick for measurement.
図4は、土壌16に熱電対センサ5を密着させるための土壌用アタッチメントで、内径10.1mm、外径12mm、長さ300mmのアルミ収納管14の下端にはステンレス製200メッシュ金網をエポキシ接着剤19で固定し、外径10mm、長さ23mmの熱電対センサ5を上端より内挿して、ビニルテープで固定して防水する。熱電対センサ5の凹型チャンバーの開口部はステンレス製200メッシュ金網を介して測定土壌16に密着するようにして、土壌水分ポテンシャルを計測する FIG. 4 shows an attachment for soil for bringing the thermocouple sensor 5 into close contact with the soil 16. A stainless 200 mesh wire mesh is epoxy-bonded to the lower end of an aluminum storage tube 14 having an inner diameter of 10.1 mm, an outer diameter of 12 mm, and a length of 300 mm. It is fixed with agent 19, and a thermocouple sensor 5 having an outer diameter of 10 mm and a length of 23 mm is inserted from the upper end and fixed with vinyl tape to make it waterproof. The opening of the concave chamber of the thermocouple sensor 5 is brought into close contact with the measurement soil 16 via a stainless steel 200 mesh wire mesh to measure the soil moisture potential.
1 パソコン
2 通信用USBケーブル
3 サイクロメータ計測器本体
4 センサ接続ケーブル
5 熱電対センサ
6 ステンレス製円筒保護管
7 円形テフロン棒
8 露点計測用のE型湿接点熱電対
9 気温計測用のT型乾接点熱電対
10 測定資料
11 作物葉
12 洗濯バサミ
13 バネ
14 アルミ収納管
15 ロック棒
16 土壌
17 ステンレス製金網
18 熱電対基部銅線
19 エポキシ接着剤
20 Φ25μmクロメル線
21 Φ25μmコンスタンタン線
22 0.3SQ2芯銅線シールド線
23 コネクター
1 PC 2 Communication USB cable 3 Cyclometer measuring instrument body 4 Sensor connection cable 5 Thermocouple sensor 6 Stainless steel cylindrical protective tube 7 Circular Teflon rod 8 E-type wet contact thermocouple for dew point measurement 9 T-type dry for temperature measurement Contact thermocouple 10 Measurement data 11 Crop leaf 12 Washing scissors 13 Spring 14 Aluminum storage tube 15 Lock rod 16 Soil 17 Stainless steel wire mesh 18 Thermocouple base Copper wire 19 Epoxy adhesive 20 Φ25 μm Chromel wire 21 Φ25 μm Constantan wire 22 0.3SQ 2 cores Copper wire shielded wire 23 connector
Claims (5)
このパソコンによって一連の計測手順を制御し、かつデジタル計測値を自動記録させ、前記測定試料の水ポテンシャルを算出・表示するペルチィア型熱電対サイクロメータにおいて、
前記計測手順として、前記凹型チャンバー内の気温Tと平衡した前記湿接点のゼーベック効果による熱電対起電力Vを最初オフセットして0μVとし、次に逆電流を流すとペルチィエ効果により冷却されて前記湿接点上に水滴が結露したのち通電を停止すると、
この湿接点のマイナスの熱電対起電力Vの変動は、最初に通電停止によって急激に上昇し、次に結露水の気化によってゆっくり温度上昇する平坦信号を示し、次に参照接点からの熱の流入により最初のオフセット電圧0μVまで上昇する復元曲線を示すが、この復元曲線のうち前記結露水の気化によってゆっくり上昇する前記平坦信号の始まる変曲点起電力Vdが前記露点温度であるので、この復元曲線上の前記変曲点起電力Vdを読み取り可能な、本計測器における前記露点温度を示す変曲点起電力Vdの自動読み取りパソコン用プログラムソフトにおいて、
冷却通電停止後の前記湿接点の前記マイナスの熱電対起電力Vの変動を微小時間Δt秒毎にV1、V2、V3、V4、・・・・Vn,Vn+1、Vn+2、・・・・とデジタル記録されるとき、Δt秒毎の熱電対起電力Vの時間差分ΔV/ΔtをΔVn=Vn―Vn+1と定義し、Δt秒毎の二階時間差分のΔ2V/Δt2をΔΔVn=ΔVn−ΔVn+1と定義するとき、1)適正冷却時での前記変曲点起電力Vdは、最初にΔ2V/Δt2≧0となるV値であり、2)過冷却時での前記変曲点起電力Vdは、最初にΔV/Δt≧0となるリバウンドV値であることから、
全体として両者の早い時刻でのV値、または両者の同時刻でのV値を前記変曲点起電力Vdとする、前記自動読み取りパソコン用プログラムソフトにより、
自動的に読み取られた前記湿接点の前記変曲点起電力Vdと、常時計測される前記乾接点の気温Tと、事前に求められた25℃検量線から、最終目的である前記測定試料の25℃水ポテンシャル値(浸透圧値)Ψ25を直接算出表示することを特徴とする非破壊、連続、自動計測するペルチィア型熱電対サイクロメータ。 The opening of the concave chamber is pressed against the measurement sample to bring it into close contact with the measurement sample, and two thermocouples, a dry contact for measuring the temperature T in the concave chamber and a wet contact for measuring the dew point temperature, are built in the concave chamber. When connecting the sensor to the main body of the cyclometer measuring instrument with a sensor connection cable and connecting the main body of the cyclometer measuring instrument to a personal computer with a USB communication cable,
In a Peltier thermocouple cyclometer that controls a series of measurement procedures with this personal computer, automatically records digital measurement values, and calculates and displays the water potential of the measurement sample.
As the measurement procedure, the thermocouple electromotive force V due to the Seebeck effect of the wet contact, which is in equilibrium with the air temperature T in the concave chamber, is first offset to 0 μV, and then when a reverse current is passed, it is cooled by the Pertier effect and the humidity is increased. When the energization is stopped after water droplets have formed on the contacts,
The fluctuation of the negative thermocouple electromotive force V of this wet contact shows a flat signal that first rises sharply due to the stoppage of energization, then slowly rises in temperature due to the vaporization of condensed water, and then the inflow of heat from the reference contact. The restoration curve that rises to the initial offset voltage of 0 μV is shown. Of this restoration curve, the turning point electromotive force Vd at which the flat signal that slowly rises due to the vaporization of the condensed water is the dew point temperature. In the program software for a personal computer that can read the turning point electromotive force Vd on the curve and automatically reads the turning point electromotive force Vd indicating the dew point temperature in this measuring instrument.
The fluctuation of the negative thermoelectric countermotive force V of the wet contact after the cooling energization is stopped is changed every minute time Δt seconds to V 1 , V 2 , V 3 , V 4 , ... Vn, Vn + 1 , Vn + 2, when ... and digitally recorded, the time difference [delta] V / delta] t of the thermoelectric TaiOkoshi power V of each delta] t seconds is defined as ΔVn = Vn-Vn +1, the second floor time difference for each delta] t seconds delta 2 when defining the V / delta] t 2 and ΔΔVn = ΔVn-ΔVn +1, 1 ) the varying KyokutenOkoshi power Vd at the time of proper cooling is the first to be Δ 2 V / Δt 2 ≧ 0 V value, 2) Since the turning point electromotive force Vd at the time of overcooling is a rebound V value at which ΔV / Δt ≧ 0 first,
As a whole, the program software for the automatic reading personal computer, which sets the V value at the earlier time of both or the V value at the same time of both as the inflection point electromotive force Vd,
From the automatically read inflection point electromotive force Vd of the wet contact, the temperature T of the dry contact that is constantly measured, and the 25 ° C. calibration curve obtained in advance, the final object of the measurement sample is non-destructive and calculates display 25 ° C. water potential value (osmotic value) [psi 25 directly, continuously, Peruchiia type thermocouple psychrometer for automatically measuring.
センサ毎の固有な検量線は前記25℃検量線であるため、気温Tにおける前記変曲点起電力Vdを25℃変曲点起電力V25に換算してのち、25℃検量線Ψ25=f(V25 2)に代入して前記水ポテンシャル値(浸透圧値)Ψ25を求めるが、
前記変曲点起電力Vdの日変化は気温Tの2次回帰式で相関され、その2次回帰式にT=25℃を代入したら前記25℃変曲点起電力V25が得られるが、更に前記変曲点起電力Vdと前記25℃変曲点起電力V25との比Vd/V25の日変化は気温Tに依存し、センサ毎の固有な温度補正式はVd/V25=f(T2)で相関されるので、
前記気温Tでの前記変曲点起電力Vdを、センサ毎に求められた固有な温度補正式の両項を取り替えたV25=Vd/f(T2)に代入して前記25℃変曲点起電力V25に換算し、更に25℃検量線Ψ25=f(V25 2)に代入して、最終目的である前記測定試料の水ポテンシャル値(浸透圧値)Ψ25を直接算出表示することを特徴とする請求項1に記載の非破壊、連続、自動計測するペルチィア型熱電対サイクロメータ。 In the temperature compensation method to enable on-site measurement with drastic temperature fluctuations
Because unique calibration for each sensor is the 25 ° C. calibration curve, later in terms of the varying KyokutenOkoshi power Vd at temperature T to 25 ° C. HenkyokutenOkoshi power V 25, 25 ° C. calibration curve [psi 25 = the water potential values are substituted into f (V 25 2) While obtaining the (osmotic value) [psi 25,
The daily change of the inflection point electromotive force Vd is correlated by the quadratic regression equation of the temperature T, and if T = 25 ° C. is substituted into the quadratic regression equation, the 25 ° C. inflection point electromotive force V 25 can be obtained. Further, the daily change of the ratio Vd / V 25 of the inflection point electromotive force Vd and the 25 ° C. inflection point electromotive force V 25 depends on the temperature T, and the unique temperature correction formula for each sensor is Vd / V 25 =. Since it is correlated with f (T 2 ),
The 25 ° C. change is substituted by substituting the change point electromotive force Vd at the temperature T into V 25 = Vd / f (T 2 ) in which both terms of the unique temperature correction formula obtained for each sensor are replaced. It converted into TenOkoshi power V 25, further by substituting the 25 ° C. calibration curve Ψ 25 = f (V 25 2 ), calculated directly display the last is the object the water potential values of the measurement sample (osmotic value) [psi 25 The Peltier type thermocouple cyclometer according to claim 1, wherein the non-destructive, continuous, and automatic measurement is performed.
請求項1での変曲点起電力Vdは冷却電流と冷却時間とによって大きく影響されるので、センサ毎に固有な適正な冷却電流と冷却時間を必ず計測開始前に設定して計測することとし、
センサ毎に固有な25℃検量線の作成は、25℃の恒温室内で検定するか、25℃の既知の浸透圧Ψ25を持つ濃度別溶液の測定に対して、請求項2の温度補正に従って気温Tでの前記変曲点起電力Vdを前記25℃変曲点起電力V25に換算したのち、この25℃変曲点起電力V25と既知の浸透圧Ψ25をプロットして、センサ毎に固有なV 25の2次回帰曲線、つまりΨ25=f(V25 2)を得ることにより行われることを特徴とする請求項1又は2に記載の非破壊、連続、自動計測するペルチィア型熱電対サイクロメータ。 In a configuration that discloses a method for creating the 25 ° C. calibration curve unique to each sensor,
Since the inflection point electromotive force Vd according to claim 1 is greatly affected by the cooling current and the cooling time, the appropriate cooling current and cooling time unique to each sensor must be set and measured before the start of measurement. ,
The creation of a 25 ° C. calibration curve unique to each sensor is to be tested in a constant temperature room at 25 ° C. or according to the temperature correction of claim 2 for measurements of concentrated solutions with a known osmotic pressure of Ψ25 at 25 ° C. After converting the turning point electromotive force Vd at the temperature T to the 25 ° C. turning point electromotive force V 25 , the 25 ° C. turning point electromotive force V 25 and the known osmotic pressure Ψ 25 are plotted and the sensor is used. nondestructive according to claim 1 or 2, characterized in that is carried out by obtaining second order regression curve of unique V 25, that is [psi 25 = f a (V 25 2) each, continuous, Peruchiia for automatically measuring Type thermocouple cyclometer.
前記湿接点の前記変曲点起電力Vdと前記乾接点の気温Tと前記25℃検量線から、前記葉の25℃換算の水ポテンシャル値Ψ25を直接算出表示することを特徴とする請求項1〜3のいずれか1項に記載の非破壊、連続、自動計測するペルチィア型熱電対サイクロメータ。 The water potential value is the water potential value of a leaf, and the leaf is sandwiched by a clothespin-type leaf attachment, and the thermocouple sensor is inserted from below into an aluminum storage tube attached to the lower surface of the clothespin. And fix it, and measure by bringing the opening of the concave chamber into close contact with the back of the leaf with many stomata.
The claim is characterized in that the water potential value Ψ 25 in terms of 25 ° C. of the leaf is directly calculated and displayed from the inflection point electromotive force Vd of the wet contact, the temperature T of the dry contact, and the 25 ° C. calibration curve. The Peltier type thermocouple cyclometer for non-destructive, continuous, and automatic measurement according to any one of 1 to 3.
前記湿接点の前記変曲点起電力Vdと前記乾接点の気温Tと前記25℃検量線から、前記土壌の25℃換算の水ポテンシャル値Ψ25を直接算出表示することを特徴とする請求項1〜3のいずれか1項に記載の非破壊、連続、自動計測するペルチィア型熱電対サイクロメータ。 The water potential value is the water potential value of soil, and an attachment for soil in which a fine stainless wire mesh having a mesh of 40 mesh or more is stretched at the lower end of an aluminum storage pipe having a predetermined length is embedded vertically downward in the soil. The thermocouple sensor is inserted into the aluminum storage pipe from above, the upper end of the aluminum storage pipe is wrapped with vinyl tape to fix the sensor connection cable to make it waterproof, and the opening of the concave chamber is opened to the wire mesh. It is measured by pressing it under the soil through
The claim is characterized in that the water potential value Ψ 25 in terms of 25 ° C. of the soil is directly calculated and displayed from the inflection point electromotive force Vd of the wet contact, the temperature T of the dry contact, and the 25 ° C. calibration curve. The Peltier type thermocouple cyclometer for non-destructive, continuous, and automatic measurement according to any one of 1 to 3.
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