JP2013167450A

JP2013167450A - Weighing apparatus

Info

Publication number: JP2013167450A
Application number: JP2012029064A
Authority: JP
Inventors: Yoshikazu Nagane; 吉一長根; Yoshikuni Sato; 嘉國佐藤
Original assignee: A&D Co Ltd
Current assignee: A&D Holon Holdings Co Ltd
Priority date: 2012-02-14
Filing date: 2012-02-14
Publication date: 2013-08-29
Anticipated expiration: 2032-02-14
Also published as: JP6049001B2

Abstract

PROBLEM TO BE SOLVED: To provide an electronic balance with a static elimination function, which is provided with a self-diagnostic function of static elimination ability and is capable of diagnosing suitable cleaning/replacement timing of a static elimination needle by itself while considering a deterioration state.SOLUTION: An electronic balance 1 including a weighing chamber 5, a load measuring mechanism 13 and static elimination means 11A to 11D each on which one or more plus static elimination needles and the same number of minus static elimination needles are arranged includes also needle deterioration evaluation means for applying/stopping voltage to the static elimination means 11A to 11D, detecting variation of measurement data in no load before and after applying the voltage by the load measuring mechanism 13 and finding out an inherent variation amount of the measurement data. Variation of the measurement data in no load following ion air caused by corona discharge from each static elimination needle is measured by the load measuring mechanism, an evaluation index for self-diagnosis of static elimination ability is acquired by the needle deterioration evaluation means, and while considering a deterioration state of the static elimination needle, needle cleaning/replacement timing is diagnosed by the electronic balance itself.

Description

本発明は、電子天秤に係り、特に除電機能を有する電子天秤に関する。 The present invention relates to an electronic balance, and more particularly to an electronic balance having a charge removal function.

計量値の読み取り精度（最小表示）が０．１ｍｇ以下の分析用電子天秤、さらには１μｇ以下の超高精度のマイクロ(ミクロ)電子天秤のような、高分解能の電子天秤では、計測対象物である試料そのものが帯電した状態で測定すると、静電気の影響により、測定誤差が生じてしまう。 In a high-resolution electronic balance such as an analytical electronic balance with a reading accuracy (minimum display) of 0.1 mg or less, or an ultra-high precision micro balance with 1 μg or less, If measurement is performed while a sample is charged, a measurement error occurs due to the influence of static electricity.

これに対し、計量室と背後の機構室とを有し、計量室の後壁の背後の機構室に各除電針に電圧を印加する除電器が配置された、除電機能付き電子天秤が提案されている（特許文献１）。係る電子天秤では、除電モードに入ると、各除電針のコロナ放電により計量室内にプラスイオンとマイナスイオンとを充満させ、イオンの重複エリアにて、試料に帯電している電荷を中和する（以下、除電と称す）。これにより、静電気の影響を受けることなく当該試料の計量を行うことができる。 On the other hand, an electronic balance with a charge eliminating function has been proposed that has a weighing chamber and a mechanism chamber behind it, and a static eliminator that applies voltage to each charge eliminating needle is arranged in the mechanism chamber behind the rear wall of the weighing chamber. (Patent Document 1). In such an electronic balance, when the static elimination mode is entered, positive ions and negative ions are filled in the measurement chamber by corona discharge of each static elimination needle, and the charge charged on the sample is neutralized in the ion overlap area ( Hereinafter referred to as static elimination). Thereby, the sample can be weighed without being affected by static electricity.

特開２０１０−１９０６００（段落００１５〜００２１、００２５、図１〜３等）JP 2010-190600 (paragraphs 0015-0021, 0025, FIGS. 1-3, etc.)

しかし、前述した従来のコロナ放電を利用した除電機能付き電子天秤では、除電針による除電能力が劣化していても気付かずに使用している場合や、周囲環境による違いや個体差のあるそれぞれの電子天秤で、除電針の清掃・交換のメンテナンスをどの程度の頻度で行えば良いか分からない、また、メンテナンスを行ってもその効果が確認できないという問題があった。具体的には以下である。 However, in the electronic balance with a static elimination function using the conventional corona discharge described above, when the static elimination capability of the static elimination needle is deteriorated, it is used without notice, or there are differences depending on the surrounding environment and individual differences. There is a problem that it is difficult to know how often the electronic balance should be cleaned and replaced with an electronic balance, and the effect cannot be confirmed even if maintenance is performed. Specifically:

（ｉ）除電針の劣化は、プラス針とマイナス針とで劣化の進行が異なる事が確認されている。プラス針では、周辺の空気中の分子（一般に水分子）が電離されプラスイオンになるが、電離するときに放出される電子が針に衝突して先端が磨耗し、イオン生成能力が劣化する傾向にある。マイナス針では、電子の衝突は無いが二酸化ケイ素等が先端に結晶として付着し汚れてくるのでイオン生成能力が劣化し、イオン生成能力が劣化する傾向にある。よって、全体としては、短期的には異物が付着するマイナスイオン針が先にイオン生成能力が劣化し、中長期的にはプラスイオン針の先端が磨耗するためゆっくりイオン生成能力が落ちていく現象となる。また、プラス/マイナスの各電極が汚れてくると、その度合いに応じてそれぞれの供給イオン量のバランスがくずれることとなり、適切に除電されない場合がある。よって、除電針のメンテナンスをするにしても、どの電極の針をどのタイミングで清掃したり交換したりすべきなのか、ユーザ側では認識のしようがなかった。 (I) It has been confirmed that the progress of the deterioration of the static elimination needle differs between the plus needle and the minus needle. In the plus needle, the molecules in the surrounding air (generally water molecules) are ionized to become positive ions, but the electrons emitted when ionizing collide with the needle and the tip wears out, and the ion generation ability tends to deteriorate. It is in. In the minus needle, there is no collision of electrons, but silicon dioxide or the like adheres as a crystal to the tip and becomes dirty, so that the ion generation ability deteriorates and the ion generation ability tends to deteriorate. Therefore, as a whole, the negative ion needle to which foreign matter adheres in the short term deteriorates the ion generation capability first, and the ion generation capability gradually declines in the medium to long term because the tip of the positive ion needle wears out. It becomes. In addition, when each plus / minus electrode becomes dirty, the balance of the amount of each supplied ion is lost depending on the degree, and there is a case where the charge is not properly eliminated. Therefore, even if the static elimination needle is maintained, the user has no way of knowing which electrode needle should be cleaned or replaced at which timing.

（ｉｉ）除電針の寿命（交換時期）としては一般的に、タングステン製では２年、ＳＵＳ製では１年などが針交換の目安と言われているが、電圧印加積算時間が考慮されたものではなく、また周囲環境（大気中のパーティクルの状態）の違いや天秤の個体差を考慮したものでも無いため、適切なメンテナンスが行えるものではなかった。 (Ii) The life (replacement time) of the static elimination needle is generally 2 years for tungsten and 1 year for SUS. In addition, since it does not take into account differences in the surrounding environment (the state of particles in the atmosphere) and individual differences in the balance, appropriate maintenance could not be performed.

（ｉｉｉ）針交換を行っても、除電針と除電器との接触不良、或いは除電針とは別に内部の電子回路や配線、接触不良等による故障などにより、除電がされていない場合も生じうるが、これらが要因かどうかユーザ側では不明であった。
以上のことから、ユーザは非効率な針清掃・交換メンテナンスをするか、もしくは除電能力の劣化を放置したまま使用し、またメンテナンスが確実に実行されたか不安に思いながら使用していた。 (Iii) Even if the needle is replaced, there may be a case where static elimination is not performed due to poor contact between the static elimination needle and the static eliminator, or a failure due to an internal electronic circuit, wiring, poor contact, etc. separately from the static elimination needle. However, it was unclear on the user side whether these were the factors.
From the above, the user has performed inefficient needle cleaning / replacement maintenance, or used it while leaving the deterioration of the static elimination capability, and used it with anxiety whether the maintenance has been performed reliably.

本発明は、従来技術の問題点に基づいて為されたもので、その目的は、第１に、除電能力（プラス/マイナス電極のイオン生成能力）の自己診断機能を備えた除電機能付き電子天秤を提供することであり、第２に、自己診断機能によりその劣化状態をふまえた上で、適切な除電針の清掃・交換タイミングはいつか等を自身で診断することのできる除電機能付き電子天秤を提供するものである。 The present invention has been made on the basis of the problems of the prior art. The first object of the present invention is to provide an electronic balance with a static elimination function having a self-diagnosis function of the static elimination capability (plus / minus electrode ion generation capability). Secondly, an electronic balance with a static elimination function that can diagnose when the appropriate timing for cleaning / replacement of the static elimination needle is determined by the self-diagnosis function based on its deterioration state. It is to provide.

前記目的を達成するために、請求項１に係る除電機能付き電子天秤においては、計量室と、前記計量室に載置された試料の計量値を計測する荷重計測機構と、プラスの除電針及びマイナスの除電針をそれぞれ１個以上同数個配置した除電手段と、を備える除電機能付き電子天秤であって、前記除電手段に電圧を印加，停止し、前記荷重計測機構にて電圧印加前後の無負荷時の計量データの変動を検知して、該計量データの固有変動量を求める針劣化評価手段を備えることを特徴とする。 In order to achieve the above object, in the electronic balance with a charge eliminating function according to claim 1, a weighing chamber, a load measuring mechanism for measuring a measured value of a sample placed in the weighing chamber, a positive charge eliminating needle, An electronic balance with a static elimination function, comprising one or more negative static elimination needles arranged in the same number, and applying and stopping voltage to the static elimination means, and the load measuring mechanism before and after voltage application. It is characterized by comprising needle deterioration evaluation means for detecting a change in measurement data at the time of loading and obtaining an inherent change amount of the measurement data.

請求項２では、請求項１に記載の除電機能付き電子天秤において、前記針劣化評価手段で得られた無負荷時の計量データの固有変動量が、清掃閾値よりも小さい場合であったとき、針清掃すべきであると自己診断する清掃診断手段を備えることを特徴とする。 In claim 2, in the electronic balance with a charge eliminating function according to claim 1, when the inherent variation amount of the measurement data at the time of no load obtained by the needle deterioration evaluation means is smaller than the cleaning threshold, A cleaning diagnosis means for self-diagnosis that the needle should be cleaned is provided.

請求項３では、請求項１に記載の除電機能付き電子天秤において、前記針劣化評価手段で得られた無負荷時の計量データの固有変動量が、交換閾値よりも小さい場合であったとき、針交換すべきであると自己診断する交換診断手段を備えることを特徴とする。 In claim 3, in the electronic balance with a charge eliminating function according to claim 1, when the inherent variation amount of the measurement data at the time of no load obtained by the needle deterioration evaluation means is smaller than the replacement threshold value, It is characterized by comprising an exchange diagnostic means for self-diagnosis that the needle should be exchanged.

請求項４では、請求項１に記載の除電機能付き電子天秤において、前記針劣化評価手段で得られた無負荷時の計量データの固有変動量が、故障閾値よりも大きい場合であったとき、装置故障であると自己診断する故障診断手段を備えることを特徴とする。 In claim 4, in the electronic balance with a charge eliminating function according to claim 1, when the inherent variation amount of the measurement data at no load obtained by the needle deterioration evaluation means is larger than a failure threshold, A failure diagnosis means for self-diagnosis that the device is faulty is provided.

請求項５では、請求項２〜４のいずれかに記載の除電機能付き電子天秤において、前記交換診断手段、前記清掃診断手段、前記故障診断手段の後に、再度前記針劣化評価手段により無負荷時の計量データの固有変動量を求め、再度前記交換診断手段、前記清掃診断手段、前記故障診断手段を行う効果確認手段を備えることを特徴とする。 In Claim 5, in the electronic balance with a charge eliminating function according to any one of Claims 2 to 4, after the replacement diagnosis unit, the cleaning diagnosis unit, and the failure diagnosis unit, the needle deterioration evaluation unit again causes no load. And an effect confirmation unit that obtains the inherent variation amount of the measurement data and performs the replacement diagnosis unit, the cleaning diagnosis unit, and the failure diagnosis unit again.

請求項６では、請求項１〜５のいずれかに記載の除電機能付き電子天秤において、前記除電針に電圧を印加した電圧印加積算時間を計測・評価する積算時間評価手段を備え、基準積算時間に対し、電圧印加積算時間が基準積算時間以上に長くなった場合、前記針劣化評価手段を自動で行うことを特徴とする。 In Claim 6, in the electronic balance with a charge eliminating function according to any one of Claims 1 to 5, provided with an integrated time evaluation means for measuring and evaluating a voltage application integrated time in which a voltage is applied to the charge eliminating needle, and a reference integrated time On the other hand, when the voltage application integration time becomes longer than the reference integration time, the needle deterioration evaluation means is automatically performed.

請求項７では、請求項１〜６のいずれかに記載の除電機能付き電子天秤において、前記針劣化評価手段を、前記除電針に対し単極ずつ行うことを特徴とする。 According to a seventh aspect of the present invention, in the electronic balance with a static elimination function according to any one of the first to sixth aspects, the needle deterioration evaluation means is performed for each single pole on the static elimination needle.

以上より、本願発明の除電機能付き電子天秤によれば、除電手段に電圧を印加すると、各除電針からコロナ放電が起こり、その際に微少なイオン風が発生する。本願発明では、このイオン風の発生に伴って無負荷時の計量データが変動する現象を荷重計測機構で計量し、まず、電圧印加前後での無負荷時の計量データの固有変動量（無負荷時計量データの変動分）を求める針劣化評価手段によって、除電能力の自己診断を行うための評価指標を取得する。そして、除電針の除電能力が良好（針先が鋭利で、かつ汚れも略無い状態）であるときに発生するイオン風は所定量であり、従ってこれに伴う無負荷時の計量データの固有変動量も所定範囲内である。本願発明では、この現象を利用して、該計量データの固有変動量が良好状態所定範囲（規定範囲）より小さければ清掃が必要であり、清掃後にも、該計量データの固有変動量が一定値以下であれば交換が必要と判断できる。逆に、該計量データの固有変動量が一定値より高い場合は何らかの故障のおそれありと判断できる。 As described above, according to the electronic balance with a static elimination function of the present invention, when a voltage is applied to the static elimination means, corona discharge occurs from each static elimination needle, and a minute ion wind is generated at that time. In the present invention, the phenomenon in which the measurement data at the time of no load fluctuates due to the generation of the ion wind is measured by the load measuring mechanism. First, the inherent fluctuation amount of the measurement data at the time of no load before and after the voltage application (no load) An evaluation index for performing a self-diagnosis of the static elimination capability is acquired by a needle deterioration evaluation means for obtaining a fluctuation amount of the clock amount data). And the ion wind that is generated when the static elimination needle has a good static elimination capability (the needle tip is sharp and almost free from dirt) is a predetermined amount. The amount is also within a predetermined range. In the present invention, by utilizing this phenomenon, cleaning is necessary if the inherent variation amount of the measurement data is smaller than the predetermined range (specified range) in the good state. Even after cleaning, the inherent variation amount of the measurement data is a constant value. If it is below, it can be determined that replacement is necessary. On the contrary, if the inherent variation amount of the measurement data is higher than a certain value, it can be determined that there is a possibility of some failure.

即ち、針劣化評価手段に、清掃診断手段、交換診断手段を備えることにより、コロナ放電に伴う無負荷時の計量データの変動現象と天秤の従来機能である荷重計測機能とを利用して、除電針の除電能力の自己診断機能を備えた電子天秤を提供することができる。これにより、除電針の劣化状態をふまえた上で、適切な針清掃・交換タイミングはいつかを、天秤自身で診断することができる。よって、従来のように、天秤の周囲環境の善し悪しに関わらず一律に設定されていた針清掃・交換指示とは異なり、周囲環境の状態も考慮された上の指示となるため、ユーザは適切な針清掃・交換メンテナンスが行える。また、併せて故障診断手段を備えることにより、除電能力の大きさを検出・診断し、除電器内の印加電圧の異常を含めた故障を天秤自身で発見できる。 That is, by providing the needle deterioration evaluation means with a cleaning diagnosis means and an exchange diagnosis means, it is possible to eliminate static electricity by utilizing the phenomenon of fluctuation of measurement data at no load accompanying corona discharge and the load measurement function that is a conventional function of a balance. An electronic balance equipped with a self-diagnosis function of the needle's charge removal capability can be provided. Thus, the balance itself can diagnose when the appropriate needle cleaning / replacement timing is based on the deterioration state of the static elimination needle. Therefore, unlike conventional needle cleaning / replacement instructions that are set uniformly regardless of whether the environment around the balance is good or bad, the user is given an appropriate instruction because the surrounding environment is taken into consideration. Needle cleaning and replacement maintenance can be performed. In addition, by providing failure diagnosis means, it is possible to detect and diagnose the magnitude of the charge removal capability, and to find a failure including an abnormality in the applied voltage in the charge remover by the balance itself.

また、針清掃や交換を行った場合、確実に汚れが払拭できたかどうか、針が正しく接触しているか等がユーザには分からなかった。よって、各メンテナンス後に、各メンテナンスが確実・有効に実行されたかを天秤自身で診断することができる効果確認手段を設けることで、ユーザに不安を感じることなく使用してもらう事ができる。 In addition, when the needle was cleaned or replaced, the user did not know whether or not the dirt could be wiped off and whether the needle was in proper contact. Therefore, after each maintenance, by providing an effect confirmation means that can be diagnosed by the balance itself whether or not each maintenance has been performed reliably and effectively, the user can use it without feeling uneasy.

また、電圧を印加した時間（除電時間）を積算する事によって、積算時間のパラメータと天秤自身の無負荷時計量データの変動分とにより、効果的に針清掃タイミングや針交換のタイミングを指示することができる。即ち、係るメンテナンス指示のタイミングは、従来のように、電圧印加積算時間とは関係なしに、いかなる場合においても一律で設定されていたメンテナンス指示とは異なり、除電機能の使用状況（電圧印加積算時間）が考慮された上の指示であるため、効果的なものとなる。 Also, by accumulating the voltage application time (static elimination time), the needle cleaning timing and needle replacement timing are effectively instructed by the parameter of the integration time and the fluctuation of the unloaded clock amount data of the balance itself. be able to. That is, the timing of the maintenance instruction is not related to the voltage application integration time as in the conventional case, and is different from the maintenance instruction which is set uniformly in any case. ) Is an effective instruction because it is an instruction in consideration.

また、電圧の印加は、除電室に設けられている除電針に対して単極ずつ（プラス極又はマイナス極側の除電針に対して印加，停止したのち、他極側の除電針に対して印加，停止する）行えば、プラス針とマイナス針とで個別に評価ができるため好ましい。 In addition, the voltage is applied to each static elimination needle provided in the static elimination chamber one by one (after applying and stopping to the positive or negative polarity side static elimination needle, then to the other polarity side static elimination needle. (Applying and stopping) is preferable because the plus and minus needles can be individually evaluated.

本発明に係る電子天秤の斜視図である。It is a perspective view of the electronic balance which concerns on this invention. 同電子天秤の正面図である。It is a front view of the electronic balance. 同電子天秤の構成を示すブロック図である。It is a block diagram which shows the structure of the electronic balance. 同電子天秤の自己診断手段処理フローを示すフローチャートであって、積算時間評価手段の一例を示すものIt is a flowchart which shows the self-diagnosis means processing flow of the electronic balance, and shows an example of the accumulated time evaluation means 針劣化評価手段の一例を示すものAn example of needle deterioration evaluation means 故障診断手段・清掃診断手段の一例を示すものAn example of failure diagnosis means / cleaning diagnosis means 交換診断手段の一例を示すものである。An example of the replacement diagnosis means is shown. 無負荷時の計量データ変化量算出のためのデータ取得タイミングを示す図である。It is a figure which shows the data acquisition timing for the measurement data change amount calculation at the time of no load. 同電子天秤の自己診断手段処理による結果表示の例であって、（ａ）故障と診断した場合の表示例、（ｂ）清掃と診断した場合の表示例、（ｃ）交換と診断した場合の表示例である。It is an example of the result display by the self-diagnosis means processing of the electronic balance, (a) display example when diagnosed as a failure, (b) display example when diagnosed as cleaning, (c) when diagnosed as replacement It is a display example.

本発明の好適な実施例の構成を図１〜３を用いて説明する。図１は本発明に係る電子天秤の斜視図、図２は同電子天秤の正面図、図３は同電子天秤の構成を示すブロック図である。 A configuration of a preferred embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of an electronic balance according to the present invention, FIG. 2 is a front view of the electronic balance, and FIG. 3 is a block diagram showing the configuration of the electronic balance.

符号１は、電子天秤の一種である電磁平衡式の電子天秤であり、装置前部には計量皿２が配置された計量室５が形成され、計量室５の後部（装置後部）には機構室３が形成されている。符号４は仕切板であり、電子天秤１の計量室５の空間を上下に仕切るように配置され、これにより上部空間が後述する除電部６、下部空間が計量部７に区間形成されている。なお、上記電子天秤１の構成は一例であって、仕切り板４により計量室５を分けることは、本願にとって必須の構成ではない。 Reference numeral 1 denotes an electromagnetic balance type electronic balance which is a kind of electronic balance. A weighing chamber 5 in which a weighing pan 2 is arranged is formed at the front of the device, and a mechanism is provided at the rear of the weighing chamber 5 (the rear of the device). A chamber 3 is formed. Reference numeral 4 denotes a partition plate, which is arranged so as to partition the space of the weighing chamber 5 of the electronic balance 1 into upper and lower portions, whereby the upper space is sectioned in the charge removing portion 6 and the lower space, which will be described later. In addition, the structure of the said electronic balance 1 is an example, Comprising: Dividing the measurement chamber 5 by the partition plate 4 is not an essential structure for this application.

除電部６の後壁６Ａには、直流型イオン発生手段として複数（図示の構成では４個）の除電針が配置されている。例えば除電針１１Ａと１１Ｄはプラス極、除電針１１Ｂと１１Ｃはマイナス極に設定することによりプラス極，マイナス極の除電針が上下左右に交互に同数個ずつ配置された構成となった、除電手段が設けられている。各除電針１１Ａ〜１１Ｄの背後には、後壁６Ａを介して機構室３内に除電針にイオン発生用の高電圧を印加するための除電器１２が配置されている。各除電針１１Ａ〜１１Ｄは、除電針を周方向に囲うリング状の防護ホルダー内に収納されるとともにユニット化されており、この除電針ユニットは特別な工具を用いることなく除電針を簡単かつ安全に挿着脱できるようになっている。なお、除電針の設置数は図示の４本に限るものではなく、より多数配置したり、或いは逆に除電バランスがやや劣るものの、プラス極，マイナス極の２本の除電針を配置する構成も可能である。 A plurality of (four in the illustrated configuration) static elimination needles are arranged on the rear wall 6A of the static elimination unit 6 as DC ion generating means. For example, the static elimination needles 11A and 11D are set as positive poles, and the static elimination needles 11B and 11C are set as negative poles so that the same number of static elimination needles of positive and negative poles are alternately arranged in the vertical and horizontal directions. Is provided. Behind each static elimination needle 11A-11D, the static elimination device 12 for applying the high voltage for ion generation to the static elimination needle is arrange | positioned in the mechanism chamber 3 via the rear wall 6A. Each static elimination needle 11A to 11D is housed in a ring-shaped protective holder that surrounds the static elimination needle in the circumferential direction and is unitized. This static elimination needle unit is simple and safe without using a special tool. Can be inserted and removed. Note that the number of static elimination needles is not limited to the four shown in the figure, and a configuration in which a large number of static elimination needles are arranged, or conversely, the static elimination balance is slightly inferior, but two static elimination needles of plus and minus poles are arranged. Is possible.

計量部７は、仕切板４を介して除電部６の下方に位置しており、計量部７の下部には計量皿２が設けられている。機構室３には、計量皿２に載置された試料の計量値を計測するための電磁部及び電磁部に荷重を伝達する荷重伝達機構、ＣＰＵ，メモリ等を搭載した電子回路等が配置された荷重計測機構１３が設けられている。符号１５、１６、１７は湿度センサであって、検知した湿度に応じて試料の除電の要否を表示部８に表示する。 The measuring unit 7 is located below the static eliminating unit 6 with the partition plate 4 interposed therebetween, and the measuring pan 2 is provided below the measuring unit 7. In the mechanism chamber 3, an electromagnetic part for measuring the measured value of the sample placed on the weighing pan 2, a load transmission mechanism for transmitting a load to the electromagnetic part, an electronic circuit equipped with a CPU, a memory, and the like are arranged. A load measuring mechanism 13 is provided. Reference numerals 15, 16, and 17 denote humidity sensors, which display on the display unit 8 whether or not the sample needs to be neutralized according to the detected humidity.

そして、本願の除電機能付き電子天秤１は、荷重計測機構１３に、除電針１１Ａ〜１１Ｄに電圧を印加，停止し、電圧印加前後での無負荷時の計量データ（以下、ゼロ点と称す）の変動を検知して、該計量データの固有変動量（ゼロ点の変化量Ｒｎ）を求める針劣化評価手段と、針劣化評価手段で得られたゼロ点変化量Ｒｎが、交換閾値Ｒ３、清掃閾値Ｒ２に対しＲ３≦Ｒｎ＜Ｒ２であったとき、針清掃すべきであると自己診断する清掃診断手段と、針劣化評価手段で得られたＲｎが、交換閾値Ｒ３に対しＲｎ＜Ｒ３であったとき、針交換すべきであると自己診断する交換診断手段と、前記針劣化評価手段で得られたＲｎが、故障閾値Ｒ１に対しＲｎ＞Ｒ１であったとき、装置故障であると自己診断する故障診断手段と、除電針１１Ａ〜１１Ｄに電圧を印加した電圧印加積算時間Ｔａｍを計測し基準積算時間Ｔに対しＴａｍ≧Ｔとなったときに、前記針劣化評価手段を自動で行う積算時間評価手段と、前記清掃診断手段、前記交換診断手段、前記故障診断手段の後に、再度前記針劣化評価手段によりＲｎを求め、再度前記交換診断手段、前記交換診断手段、前記故障診断手段を行う効果確認手段と、を備えている。後述のフローチャートとともに具体的に説明する。 And the electronic balance 1 with a static elimination function of this application applies and stops a voltage to the static elimination needle 11A-11D to the load measurement mechanism 13, and the measurement data at the time of no load before and after voltage application (henceforth a zero point) The needle deterioration evaluation means for detecting the fluctuation of the measurement data and obtaining the inherent fluctuation amount (zero point change amount Rn) of the measurement data, and the zero point change amount Rn obtained by the needle deterioration evaluation means are the replacement threshold value R3, cleaning When R3 ≦ Rn <R2 with respect to the threshold value R2, the cleaning diagnostic means for self-diagnosis that the needle should be cleaned and the Rn obtained by the needle deterioration evaluation means satisfy Rn <R3 with respect to the replacement threshold value R3. When the replacement diagnostic means for self-diagnosis that the needle should be replaced and Rn obtained by the needle deterioration evaluation means satisfy Rn> R1 with respect to the failure threshold value R1, it is self-diagnosed as a device failure. Fault diagnosis means to perform, and static elimination needles 11A to 11 When the voltage application integrated time Tam when the voltage is applied is measured and Tam ≧ T with respect to the reference integrated time T, the needle deterioration evaluation means automatically performs the integrated time evaluation means, the cleaning diagnosis means, and the replacement After the diagnosing means and the failure diagnosing means, there is provided an effect confirmation means for obtaining Rn again by the needle deterioration evaluating means and performing the replacement diagnosing means, the replacement diagnosing means, and the failure diagnosing means again. This will be specifically described with reference to a flowchart described later.

電子天秤１の除電能力自己診断モードの作動を、図４（ａ）〜（ｄ）に示すフローチャートに基づいて説明する。図４は同電子天秤の自己診断手段処理フローを示すフローチャートであって、（ａ）積算時間評価手段の一例を示すもの、（ｂ）針劣化評価手段の一例を示すもの、（ｃ）故障診断手段・清掃診断手段の一例を示すもの、（ｄ）交換診断手段の一例を示すものであり、図５は無負荷時の計量データの変化量算出のためのデータ取得タイミングを示す図、図６は同電子天秤の自己診断手段処理による結果表示の例であって、（ａ）故障と診断した場合の表示例、（ｂ）清掃と診断した場合の表示例、（ｃ）交換と診断した場合の表示例、である。 The operation in the static elimination capability self-diagnosis mode of the electronic balance 1 will be described based on the flowcharts shown in FIGS. FIG. 4 is a flow chart showing the processing flow of the self-diagnosis means of the electronic balance, wherein (a) shows an example of accumulated time evaluation means, (b) shows an example of needle deterioration evaluation means, and (c) failure diagnosis. FIG. 5 shows an example of the means / cleaning diagnosis means, (d) shows an example of the replacement diagnosis means, and FIG. 5 is a diagram showing the data acquisition timing for calculating the change amount of the measurement data at no load, FIG. Is an example of the result display by the self-diagnosis means processing of the electronic balance, (a) display example when diagnosed as a failure, (b) display example when diagnosed as cleaning, (c) when diagnosed as replacement Is a display example.

除電能力自己診断モードに入ると、まず、ステップ１において、除電針１１Ａ〜１１Ｄの除電能力自己診断を行うタイミングとなる、基準積算時間Ｔを操作部９から設定する（一例として、Ｔ＝１時間）。次に、ステップ２で、除電針１１Ａ〜１１Ｄに高圧が印加され除電を行う。この際、電圧を印加した時間（除電時間）Ｔａｎも計測し、記憶する。次に、ステップ３で、前回、到来した基準積算時間Ｔから現在までの除電時間Ｔａｎを積算した電圧印加積算時間Ｔａｍ（Ｔａｍ＝Ｔａ１＋Ｔａ２＋Ｔａ３＋・・・＋Ｔａｎ）を求める。同時に、電子天秤１の使用開始時から現在までの除電時間Ｔａｎを全て積算した総電圧印加積算時間Ｔ´ａｍ（Ｔ´ａｍ＝Ｔａ１＋Ｔａ２＋Ｔａ３＋・・・＋Ｔａｎ）も求める。次に、ステップ４で、総電圧印加積算時間Ｔ´ａｍが、一般に除電針の寿命と言われている１００００ｈに達したか否か、即ちＴ´ａｍ≧１００００ｈであるか否かを判断する。１００００ｈ以上である場合は、ステップ５を経由してステップ２５に移行し、除電針の寿命時間につき、表示部８に“ｒＥＰＬＡＣＥ”等の針交換指示メッセージを出す、針交換指示処理（Ｄ）を行う。もっとも、ここでの交換指示は従来一般の目安によって出されるものであるので、この後の除電能力自己診断の結果次第では、ユーザの判断にて無視しても良い。一方、１００００ｈ未満の場合は、ステップ６に移行し、電圧印加積算時間Ｔａｍが基準積算時間Ｔに達したか否か、即ちＴａｍ≧Ｔであるか否かを判断する（積算時間評価手段）。基準積算時間Ｔ未満の場合は、ステップ２に戻る。基準積算時間Ｔ以上である場合は、ステップ７に移行し、電圧印加積算時間Ｔａｍをクリア、即ちＴａｍ＝０としたのち、針劣化評価処理Ａのサブルーチン（図４ｂ）へ移行する。ステップ８〜ステップ１４が、針劣化評価手段となる。 When the static elimination capability self-diagnosis mode is entered, first, in step 1, a reference integrated time T that is a timing for performing static neutralization capability self-diagnosis of the static elimination needles 11A to 11D is set from the operation unit 9 (as an example, T = 1 hour). ). Next, in step 2, a high voltage is applied to the charge removal needles 11A to 11D to perform charge removal. At this time, the voltage application time (static elimination time) Tan is also measured and stored. Next, in step 3, a voltage application integration time Tam (Tam = Ta1 + Ta2 + Ta3 +... + Tan) obtained by integrating the static elimination time Tan from the previously arrived reference integration time T to the present is obtained. At the same time, a total voltage application integration time T′am (T′am = Ta1 + Ta2 + Ta3 +... + Tan) obtained by integrating all the static elimination times Tan from the start of use of the electronic balance 1 to the present is also obtained. Next, in step 4, it is determined whether or not the total voltage application integration time T′am has reached 10000 h, which is generally referred to as the life of the static elimination needle, that is, whether T′am ≧ 10000 h. If it is 10000h or more, the process proceeds to step 25 via step 5, and a needle replacement instruction process (D) is performed in which a needle replacement instruction message such as “rEPLACE” is displayed on the display unit 8 for the life of the static elimination needle. Do. However, since the replacement instruction here is given based on a general standard, it may be ignored at the user's discretion depending on the result of the subsequent self-diagnosis. On the other hand, if it is less than 10000h, the process proceeds to step 6 to determine whether or not the voltage application integration time Tam has reached the reference integration time T, that is, whether or not Tam ≧ T (integration time evaluation means). If it is less than the reference integration time T, the process returns to step 2. If it is equal to or longer than the reference integration time T, the process proceeds to step 7 where the voltage application integration time Tam is cleared, that is, Tam = 0 is set, and then the subroutine of the needle deterioration evaluation process A (FIG. 4b) is performed. Steps 8 to 14 are needle deterioration evaluation means.

針劣化評価処理Ａでは、まず、ステップ８で、除電針１１Ａ〜１１Ｄに電圧をかけない状態で電子天秤１の無負荷時の計量データ，即ちゼロ点の安定を待ち、ゼロ点のデータ（以降、印加前データＤｎとする）を取得する。次に、ステップ９で、プラス極側除電針１１Ａ，１１Ｄ又はマイナス極側除電針１１Ｂ，１１Ｃに電圧を印加し（コロナ放電をオンとし）、除電を開始する。プラス／マイナス針への診断は、どちらから開始する設定としても良い。そして、ステップ１０で、電圧印加状態での電子天秤１のゼロ点の安定を待ち、データ（以降、印加中データＤｎ＋１とする）を取得する。次に、ステップ１１で、電圧印加を停止し（コロナ放電をオフとし）、除電を停止する。そして、ステップ１２で、電圧印加停止状態での電子天秤１のゼロ点の安定を待ち、データ（以降、印加後データＤｎ＋２とする）を取得する。なお、印加前データＤｎ，印加中データＤｎ＋１，印加後データＤｎ＋２の取得タイミングの好適な例を、図５に示す。次に、ステップ１３で、電圧印加前後のゼロ点変化量Ｒｎ、即ち、プラス極側の診断であればゼロ点のデータ変化量Ｒｎ＋を式（１）で，マイナス極側の診断であればゼロ点のデータ変化量をＲｎ−を式（２）で求める。計算の起点となるデータは、電圧印加による変化前の印加前データＤｎと印加後データＤｎ＋２の２点のデータの平均を取ることによって、天秤の微妙なゼロ変化による影響を最小限とする。
Ｒｎ＋＝Ｄｎ＋１ − {( Ｄｎ＋Ｄｎ＋２ ) ／２ } （１）
Ｒｎ− ＝Ｄｎ＋１ − {( Ｄｎ＋Ｄｎ＋２ ) ／２ } （２）
次に、ステップ１４で、プラス／マイナス極の両方の劣化を確認したか否かを判断し、一方の極しか行われていない場合はステップ８に戻り、他方の極についても評価を行う。一方、両極ともに劣化評価が行われた場合は、以降、針の清掃・故障診断処理（Ｂ），交換診断処理（Ｃ）が行われる。ステップ１５〜ステップ１６が故障診断手段、ステップ１７〜ステップ１８が清掃診断手段、ステップ２４〜ステップ２５が交換診断手段となる。 In the needle deterioration evaluation process A, first, in step 8, the electronic balance 1 is not loaded with voltage applied in a state where no voltage is applied to the static elimination needles 11 </ b> A to 11 </ b> D, that is, waits for the zero point to stabilize. , Pre-application data Dn). Next, in step 9, a voltage is applied to the positive pole side static elimination needles 11A and 11D or the negative pole side static elimination needles 11B and 11C (corona discharge is turned on), and static elimination is started. The diagnosis to the plus / minus needle may be set to start from either. In step 10, the electronic balance 1 waits for the zero point to stabilize in a voltage application state, and data (hereinafter referred to as application data Dn + 1) is acquired. Next, in step 11, voltage application is stopped (corona discharge is turned off), and static elimination is stopped. In step 12, the electronic balance 1 waits for stabilization of the zero point when the voltage application is stopped, and data (hereinafter referred to as post-application data Dn + 2) is acquired. A suitable example of the acquisition timing of the pre-application data Dn, the application data Dn + 1, and the post-application data Dn + 2 is shown in FIG. Next, in step 13, the zero point change amount Rn before and after voltage application, that is, the zero point data change amount Rn + in the case of the positive pole side diagnosis is zero in the equation (1), and the negative pole side diagnosis is zero in the case of the negative pole side diagnosis. The data change amount of the point is obtained by Rn− using the equation (2). The data that is the starting point of the calculation minimizes the influence of the delicate zero change of the balance by taking the average of the two points of the data Dn before application by the voltage application and the data Dn + 2 after application.
Rn + = Dn + 1 − {(Dn + Dn + 2) / 2} (1)
Rn− = Dn + 1 − {(Dn + Dn + 2) / 2} (2)
Next, in step 14, it is determined whether or not the deterioration of both the positive and negative poles has been confirmed. If only one of the poles has been performed, the process returns to step 8 and the other pole is also evaluated. On the other hand, when deterioration evaluation is performed for both poles, needle cleaning / fault diagnosis processing (B) and replacement diagnosis processing (C) are performed thereafter. Steps 15 to 16 are failure diagnosis means, steps 17 to 18 are cleaning diagnosis means, and steps 24 to 25 are replacement diagnosis means.

ここで、除電針１１Ａ〜１１Ｄに電圧を印加すると、各除電針からコロナ放電が起こり、その際に微少なイオン風が発生し、計量室内の空気の動きが微妙に変わるため、イオン風の発生に伴って無負荷時の計量データ（ゼロ点）が変動する。除電針１１Ａ〜１１Ｄの除電能力が良好（針先が鋭利で、かつ汚れも略無い状態）であるときに発生するイオン風は所定量であり、これに伴って検知される良好時のゼロ点変化量Ｒｎも所定範囲内である。本願の電子天秤１は、この現象を利用する。ゼロ点変化量Ｒｎが良好状態所定範囲より小さければイオン風が弱まりイオン生成能力が減衰したと判断されるので針清掃が必要であり、清掃後もゼロ点変化量Ｒｎが一定値以下ならば清掃では戻らない針劣化により針交換が必要と判断できる。逆に、ゼロ点変化量Ｒｎが良好状態所定範囲より大きければ、異常電圧が発生しているなど何らかの故障のおそれありと判断できる。 Here, when a voltage is applied to the static elimination needles 11A to 11D, corona discharge occurs from each static elimination needle, and a minute ion wind is generated at that time, and the movement of air in the measurement chamber changes slightly. As a result, the measurement data (zero point) at no load changes. The ion wind generated when the static elimination ability of the static elimination needles 11A to 11D is good (the needle tip is sharp and substantially free from dirt) is a predetermined amount, and the zero point at the time of detection detected accordingly. The change amount Rn is also within a predetermined range. The electronic balance 1 of the present application utilizes this phenomenon. If the zero point change amount Rn is smaller than the predetermined range in the good state, it is determined that the ion wind is weakened and the ion generation ability is attenuated. Needle cleaning is necessary, and after the cleaning, if the zero point change amount Rn is less than a certain value, cleaning is performed. Then, it can be determined that the needle needs to be replaced due to the deterioration of the needle that does not return. On the contrary, if the zero point change amount Rn is larger than the predetermined range in the good state, it can be determined that there is a possibility of some failure such as occurrence of abnormal voltage.

なお、良好時のゼロ点変化量Ｒｎ（以下、規定範囲と称す）は、印加電圧、除電手段の針数、荷重計測機構の能力、除電手段と計量部との距離等により異なるため、装置タイプごとに異なってくる。よって、生産時検査によってその種の電子天秤のゼロ点変化量Ｒｎの規定範囲を把握し、これに応じて、交換閾値Ｒ３，清掃閾値Ｒ２，故障閾値Ｒ１を適宜に設定する事もできる。 Note that the zero point change amount Rn (hereinafter referred to as a specified range) in a good condition varies depending on the applied voltage, the number of needles of the static elimination means, the capacity of the load measuring mechanism, the distance between the static elimination means and the measuring unit, etc. Each will be different. Therefore, it is possible to grasp the specified range of the zero point change amount Rn of this type of electronic balance by inspection during production, and to set the replacement threshold value R3, the cleaning threshold value R2, and the failure threshold value R1 accordingly.

本実施例では、各除電針への印加電圧は４ｋＶ、除電手段は前述の４本の除電針、最小表示が１μｇの超高精度のマイクロ電子天秤を用いた場合を一例に、除電針１１Ａ〜１１Ｄが全て良好状態のゼロ点変化量Ｒｎが約３０μｇ、であったことを受けて、規定範囲を２５μｇ＜Ｒｎ＜６０μｇ、故障閾値Ｒ１を６０μｇ、清掃閾値Ｒ２を２５μｇ、交換閾値Ｒ３を１５μｇに設定した。但し、これら閾値は一例である。 In this embodiment, the voltage applied to each static elimination needle is 4 kV, the static elimination means is the above-described four static elimination needles, and the case where the ultra-high precision micro electronic balance with a minimum display of 1 μg is used as an example. In response to the fact that the zero point variation Rn of all 11Ds is in a good state is about 30 μg, the specified range is 25 μg <Rn <60 μg, the failure threshold R1 is 60 μg, the cleaning threshold R2 is 25 μg, and the replacement threshold R3 is 15 μg. Set. However, these threshold values are examples.

前述の針劣化評価処理Ａにおけるステップ１４で、両極を評価したと判断されると、サブルーチンから戻り、故障・清掃診断処理（Ｂ）に移る。処理（Ｂ）では、まず、ステップ１５で、ゼロ点変化量Ｒｎが故障閾値Ｒ１を越えないか否か、即ちＲｎ＞Ｒ１を判断する。ＲｎがＲ１超となる場合は、何らかの故障と判断できるため、表示部８に図６（ａ）の故障メッセージを出す、故障通知処理（Ｆ）を行う。一方、ＲｎがＲ１以下である場合は、清掃診断処理のステップ１７に移る。 If it is determined in step 14 in the above-described needle deterioration evaluation process A that both poles have been evaluated, the process returns from the subroutine and proceeds to a failure / cleaning diagnosis process (B). In the process (B), first, in step 15, it is determined whether or not the zero point change amount Rn does not exceed the failure threshold value R1, that is, Rn> R1. When Rn exceeds R1, it can be determined that there is some failure, so failure notification processing (F) is performed in which the failure message shown in FIG. On the other hand, if Rn is equal to or less than R1, the process proceeds to step 17 of the cleaning diagnosis process.

清掃診断処理では、まず、ステップ１７で、ゼロ点変化量Ｒｎが清掃閾値Ｒ２を下回るか否か、即ちＲｎ＜Ｒ２を判断する。ＲｎがＲ２以上である場合は、規定範囲内であり、除電能力は良好に発揮されている状態であると判断できるため、ステップ２３を経由してステップ２に戻り、除電を行う場合には、除電時間Ｔａｎを計測する処理に進む。以降、除電機能が正常動作している場合は除電時間が積算され基準積算時間Ｔの周期にて針劣化評価処理Ａに移行し、針の清掃・交換の評価をする。一方、ＲｎがＲ２未満である場合は、規定範囲を下回っており、除電針に汚れが付着していると判断できるため、ステップ１８に移行し、清掃指示メッセージを出す。この際、清掃指示メッセージは、ゼロ点変化量Ｒｎ＋又はＲｎ−に基づいて、プラス極又はマイナス極側除電針のいずれに清掃が必要かを具体的に特定して指示することができる。一例として、プラス極に対する清掃指示メッセージを図６（ｂ）に示す。そして、これを受けたユーザは、ステップ１９で、指示された極側の針を清掃し、清掃後、操作部９から清掃終了キーを押す。次に、ステップ２０で、清掃終了キーが押されたか否かが判断され、キーが押されるまで待つ。キーが押された場合は、ステップ２１にて、針劣化評価処理Ａを再度実行し、清掃後のゼロ点変化量Ｒｎを改めて取得する。そして、ステップ２２で、再度Ｒｎ＜Ｒ２を判断する。清掃後のＲｎがＲ２以上である場合は、清掃の実行により規定範囲内となり、除電能力は良好に発揮されている状態となったと判断できるため、ステップ２３へ移行する。一方、ＲｎがＲ２未満である場合は、清掃を行っても除電能力改善に効果が出なかったこととなるため、交換診断処理（Ｃ）のステップ２４に移る。即ち、ステップ２０〜ステップ２２が、清掃メンテナンスの効果を検証する効果確認手段となる。 In the cleaning diagnosis process, first, in step 17, it is determined whether or not the zero point change amount Rn is below the cleaning threshold value R2, that is, Rn <R2. When Rn is equal to or greater than R2, it can be determined that it is within the specified range and the neutralization capability is being satisfactorily exhibited, so when returning to step 2 via step 23 and performing neutralization, It progresses to the process which measures static elimination time Tan. Thereafter, when the static elimination function is operating normally, the static elimination time is integrated, and the process proceeds to the needle deterioration evaluation process A at the cycle of the reference integration time T to evaluate needle cleaning / replacement. On the other hand, when Rn is less than R2, it can be determined that dirt is attached to the static elimination needle because it is below the specified range, and the process proceeds to step 18 to issue a cleaning instruction message. At this time, the cleaning instruction message can specifically specify and indicate which of the positive electrode and the negative electrode side static elimination needle needs to be cleaned based on the zero point change amount Rn + or Rn−. As an example, a cleaning instruction message for the positive pole is shown in FIG. Then, the user who has received this cleans the instructed pole-side needle and presses the cleaning end key from the operation unit 9 after cleaning. Next, in step 20, it is determined whether or not the cleaning end key has been pressed, and the process waits until the key is pressed. If the key is pressed, the needle deterioration evaluation process A is executed again at step 21 to obtain again the zero point change amount Rn after cleaning. In step 22, Rn <R2 is determined again. When Rn after cleaning is equal to or greater than R2, it can be determined that cleaning has been performed and the neutralization capability has been satisfactorily exhibited. On the other hand, if Rn is less than R2, the effect of improving the charge removal capability has not been obtained even after cleaning, and therefore the process proceeds to step 24 of the replacement diagnosis process (C). That is, step 20 to step 22 serve as effect confirmation means for verifying the effect of the cleaning maintenance.

交換診断処理（Ｃ）では、まず、ステップ２４で、ゼロ点変化量Ｒｎが交換閾値Ｒ３を下回るか否か、即ちＲｎ＜Ｒ３を判断する。ＲｎがＲ３以上である場合は、計量誤差等による故障診断の見逃しや、清掃の不十分が考えられるので、再度故障・清掃診断処理（Ｂ）へ移行する。一方、ＲｎがＲ３未満である場合は、これ以上除電能力が発揮されない状態にまで除電針が磨耗していると判断できるため、除電針の寿命と判断され、ステップ２５で、表示部８に針交換指示メッセージを出す。この際も、具体的にプラス又はマイナス極側除電針のいずれに交換が必要かを特定して指示することができる（プラス極に対する交換指示メッセージの例を図６（ｃ）に示す）。この場合、周囲の環境条件によっては一般に言われる針の寿命１００００ｈよりも早い交換となることが当然に有り得る。これを受けたユーザは、ステップ２６で、指示された極側の針を交換し、交換後、操作部９から交換終了キーを押す。次に、ステップ２７で、交換終了キーが押されたか否かが判断され、キーが押されるまで待つ。キーが押された場合は、ステップ２８にて、再度針劣化評価処理Ａを実行し、交換後のゼロ点変化量Ｒｎを改めて取得する。そして、交換後の除電能力をチェックすべく、再度故障・清掃診断処理（Ｂ）へ移行する。即ち、ステップ２７〜ステップ２８が、交換メンテナンスの効果を検証する効果確認手段となる。 In the replacement diagnosis process (C), first, in step 24, it is determined whether or not the zero point change amount Rn is below the replacement threshold R3, that is, Rn <R3. If Rn is equal to or greater than R3, the failure diagnosis due to a measurement error or the like may be overlooked or the cleaning may be insufficient. Therefore, the process proceeds to the failure / cleaning diagnosis process (B) again. On the other hand, if Rn is less than R3, it can be determined that the static elimination needle has been worn to a state where the static elimination capability is no longer exerted, and therefore it is determined that the static elimination needle has reached the end of its life. Issue exchange instruction message. Also at this time, it is possible to specify and instruct specifically which one of the plus or minus pole side static elimination needle needs to be exchanged (an example of an exchange instruction message for the plus pole is shown in FIG. 6C). In this case, depending on the surrounding environmental conditions, it is naturally possible that the needle replacement is performed earlier than the generally-known needle life of 10,000 hours. In response to this, in step 26, the user replaces the instructed pole-side needle, and after the replacement, presses the replacement end key from the operation unit 9. Next, in step 27, it is determined whether or not the replacement end key has been pressed, and the process waits until the key is pressed. If the key is pressed, the needle deterioration evaluation process A is executed again at step 28, and the zero point change amount Rn after replacement is obtained again. And in order to check the static elimination capability after replacement | exchange, it transfers to a failure and cleaning diagnosis process (B) again. That is, step 27 to step 28 serve as effect confirmation means for verifying the effect of replacement maintenance.

本実施例によれば、まず、電圧印加前後のゼロ点変化量Ｒｎを求める針劣化評価手段によって、除電能力の自己診断を行うための指標を取得する。そして、清掃診断手段、交換診断手段、故障診断手段によって、ゼロ点変化量Ｒｎが規定範囲より小さければ清掃が必要と自己診断し、清掃後にも、ゼロ点変化量Ｒｎが一定値より小さければ交換が必要と自己診断し、逆に、ゼロ点変化量Ｒｎが一定値より高い場合は何らかの故障のおそれありと自己診断するため、診断結果から自己診断機能によりその劣化状態をふまえた上で、適切な除電針の清掃・交換タイミングはいつか等を自身で診断し、ユーザに知らせることができる。即ち、除電手段からのコロナ放電に伴う無負荷時の計量データの固有変動量（ゼロ点の変動現象）と電子天秤の従来機能である荷重計測機能とを利用して、電子天秤に設置された除電針の除電能力の自己診断機能を備えた電子天秤となるため、非効率な針清掃・交換メンテナンスや、除電能力の劣化を放置したままの使用を解消することができる。 According to the present embodiment, first, an index for performing self-diagnosis of the static elimination capability is obtained by the needle deterioration evaluation means for obtaining the zero point change amount Rn before and after the voltage application. Then, the cleaning diagnosis means, the replacement diagnosis means, and the failure diagnosis means make a self-diagnosis that the cleaning is necessary if the zero point change amount Rn is smaller than the specified range, and after the cleaning, if the zero point change amount Rn is smaller than a predetermined value, replacement is performed. On the contrary, if the zero point change Rn is higher than a certain value, it will be self-diagnosed that there is a possibility of some failure. It is possible to notify the user by diagnosing by himself / herself the timing of cleaning / replacement of the static elimination needle. That is, it is installed on the electronic balance by utilizing the inherent variation amount of the measurement data at no load (corresponding to the zero point variation phenomenon) associated with the corona discharge from the static elimination means and the load measurement function that is a conventional function of the electronic balance. Since the electronic balance is equipped with a self-diagnosis function for the static elimination ability of the static elimination needle, it is possible to eliminate inefficient needle cleaning / replacement maintenance and use while leaving the static elimination ability degraded.

また、故障診断手段では、除電能力の劣化が、針の汚れ・摩耗によらない事象が原因であることが天秤自身で発見できる上に、ゼロ点変化量Ｒｎが異常に高い場合は、内部の高圧回路の異常が考えられ、ユーザへの危険信号でもあるので、コロナ放電を強制的にオフとし、危険をいち早くメッセージで知らせる事もできる（Ｅｒｒｏｒ２０）。なお、ゼロ点変化量Ｒｎがほとんどない等の場合は、内部の故障、針劣化、針のセッティングの不具合となるので針交換メッセージとして表示することも可能である(ｒＥＰＬＡＣＥ)。 In addition, in the failure diagnosis means, the balance itself can detect that the deterioration of the static elimination capability is caused by an event not caused by dirt or wear on the needle, and if the zero point variation Rn is abnormally high, An abnormality of the high-voltage circuit is considered, and it is also a danger signal to the user. Therefore, it is possible to forcibly turn off the corona discharge and promptly notify the danger (Error 20). Note that when there is almost no zero point change amount Rn, an internal failure, needle deterioration, and needle setting failure can be displayed (rEPLACE).

そして、各メンテナンス後に、各メンテナンスが確実・有効に実行されたかを電子天秤自身で診断することができる効果確認手段を設けたことで、従来のように、針清掃や交換を行った場合、確実に汚れが払拭できたかどうか、針が除電器本体に確実に接触しているか等を不安に思うことなく安心して使用してもらう事ができるため、非常にユーザフレンドリーな電子天秤となる。 And after each maintenance, by providing an effect confirmation means that can be diagnosed by the electronic balance itself whether each maintenance has been performed reliably and effectively, when needle cleaning or replacement is performed as in the past, Therefore, it can be used with confidence without worrying about whether or not dirt has been wiped off and whether or not the needle is securely in contact with the static eliminator body, so that it becomes a very user-friendly electronic balance.

また、電圧の印加は、除電室に設けられている除電針１１Ａ〜１１Ｄに対して単極ずつ行っているので、プラス針とマイナス針とで個別的な評価が出せる。なお、針劣化評価手段における除電手段への電圧の印加方法は、上記以外に、除電室に設けられている除電針全てを一斉に駆動し、時間短縮を図ってもよい。或いは、除電室に設けられている除電針を個々に順に駆動し、１つ１つの除電針の劣化状態を確認することもできる。この場合、プラス極とマイナス極との劣化の特性も同時に診断を行なうので、例えば除電針１１Ａを針Ａ，除電針１１Ｂを針Ｂ，除電針１１Ｃを針Ｃ，除電針１１Ｄを針Ｄとし、除電針１１Ｃに清掃要と自己診断した場合には“ＣＬＥＡｎＣ”と表示し、よりきめ細やかな指示が出すことも可能である。なお、除電手段への印加電圧は、直流電圧印加方式、交流電圧印加方式のいずれでも、微少なイオン風が発生する形態であれば方式を問わない。 In addition, since the voltage is applied to each of the static elimination needles 11A to 11D provided in the static elimination chamber one by one, individual evaluation can be performed using the plus needle and the minus needle. In addition to the above, the method for applying a voltage to the charge removal means in the needle deterioration evaluation means may drive all of the charge removal needles provided in the charge removal chamber all at once, thereby shortening the time. Alternatively, the static elimination needles provided in the static elimination chamber can be individually driven in order to check the deterioration state of each static elimination needle. In this case, since the deterioration characteristics of the plus and minus poles are also diagnosed at the same time, for example, the static elimination needle 11A is the needle A, the static elimination needle 11B is the needle B, the static elimination needle 11C is the needle C, and the static elimination needle 11D is the needle D. When self-diagnosis is necessary for the charge removal needle 11C, “CLEAn C” is displayed, and a more detailed instruction can be issued. The voltage applied to the static elimination means may be any system as long as a minute ion wind is generated, regardless of whether the DC voltage application system or the AC voltage application system is used.

また、除電針の除電能力自己診断を行うタイミングは、従来のように、いかなる場合においても一律で設定されていたメンテナンス指示とは異なり、積算時間評価手段を備え、電圧印加積算時間Ｔａｍを考慮に入れたことによって、効果的に針清掃タイミングや針交換のタイミングを指示することができる。なお、除電針の除電能力自己診断を行うタイミングとしては、他に、（ｉ）電子天秤を使用していない休憩時刻（例；毎日１２時３０分など）に行う、（ｉｉ）周囲温度や周囲湿度等の周囲環境が変わったとき（例；３℃変化があったときなど）に行う、（ｉｉｉ）電圧印加積算時間Ｔａｍに無関係に定期的（例；２週間毎など）に行なう、等に設定しても良い。また、（ｉｉ）で、電子天秤の自動校正のタイミングと併せて針劣化評価処理Ａを行う（例えば３℃の周囲温度変化があったときに電子天秤が自動で内蔵分銅を昇降させ校正処理を行ったのちに、針劣化評価処理Ａをスタートする）設定も好ましい。 Also, the timing for performing the self-diagnosis of the static elimination needle with the static elimination needle is different from the maintenance instruction that is set uniformly in any case as in the conventional case, and includes an integrated time evaluation means, taking into consideration the voltage application integrated time Tam. By inserting, it is possible to effectively instruct the needle cleaning timing and the needle replacement timing. In addition, there are other timings for performing the self-diagnosis of the static elimination ability of the static elimination needle: (i) Performed at a break time when the electronic balance is not used (eg, 12:30 every day), (ii) Ambient temperature and ambient Performed when the ambient environment such as humidity has changed (eg, when there has been a change of 3 ° C, etc.), (iii) Performed periodically (eg, every two weeks, etc.) regardless of the voltage application integration time Tam, etc. May be set. In (ii), the needle deterioration evaluation process A is performed together with the timing of automatic calibration of the electronic balance (for example, when the ambient temperature changes at 3 ° C., the electronic balance automatically raises and lowers the built-in weight to perform calibration processing. A setting in which the needle deterioration evaluation process A is started after it is performed is also preferable.

また、過去の２回のゼロ点変化量Ｒｎの履歴から、周囲環境等により予想以上に早めに劣化していると判断された場合は、次回の自己診断の時期を早く行う調整手段(即ち、基準積算時間Ｔを当初の設定値よりも短くする手段)を備えても良い。また、具体的に除電針の寿命から、あとどのくらい正しく除電できるかを逆算し、目安として表示部８に表しても良い。 Further, when it is determined from the past two history of the zero point change amount Rn that the deterioration has occurred earlier than expected due to the surrounding environment or the like, the adjustment means for performing the next self-diagnosis earlier (that is, (Means for shortening the reference integration time T from the initial set value). In addition, it may be calculated on the display unit 8 as a guideline by calculating back how much charge can be removed from the life of the charge removal needle.

また、イオン風をゼロ点変動として変換する際に個体差が出てくる場合もあるので、１台１台の天秤のゼロ点変化量に対応させて、故障閾値Ｒ１，清掃閾値Ｒ２，交換閾値Ｒ３の値を個々に記憶させても良い。 In addition, there may be individual differences when the ion wind is converted as a zero point variation. Therefore, the failure threshold value R1, the cleaning threshold value R2, the replacement threshold value corresponding to the zero point change amount of each balance. The value of R3 may be stored individually.

１電子天秤
３機構室
５計量室
６除電部
７計量部
１１Ａ〜１１Ｄ除電針（除電手段）
１３荷重計測機構 DESCRIPTION OF SYMBOLS 1 Electronic balance 3 Mechanism room 5 Weighing chamber 6 Static elimination part 7 Weighing part 11A-11D Static elimination needle (static elimination means)
13 Load measurement mechanism

Claims

計量室と、前記計量室に載置された試料の計量値を計測する荷重計測機構と、プラスの除電針及びマイナスの除電針をそれぞれ１個以上同数個配置した除電手段と、を備える除電機能付き電子天秤であって、
前記除電手段に電圧を印加，停止し、前記荷重計測機構にて電圧印加前後の無負荷時の計量データの変動を検知して、該計量データの固有変動量を求める針劣化評価手段を備えることを特徴とする除電機能付き電子天秤。 A neutralization function comprising a measurement chamber, a load measurement mechanism for measuring a measured value of a sample placed in the measurement chamber, and a static elimination means in which one or more plus static elimination needles and one or more negative elimination needles are arranged. Electronic balance with
A needle deterioration evaluation unit is provided that applies and stops voltage to the static elimination unit, detects a change in measurement data when no load is applied before and after the voltage application by the load measurement mechanism, and obtains an inherent variation amount of the measurement data. An electronic balance with a charge eliminating function.

前記針劣化評価手段で得られた無負荷時の計量データの固有変動量が、清掃閾値よりも小さい場合であったとき、針清掃すべきであると自己診断する清掃診断手段を備えることを特徴とする請求項１に記載の除電機能付き電子天秤。 A cleaning diagnosis means for self-diagnosis that the needle should be cleaned when the inherent variation amount of the measurement data obtained at the time of no load obtained by the needle deterioration evaluation means is smaller than a cleaning threshold is provided. The electronic balance with a charge eliminating function according to claim 1.

前記針劣化評価手段で得られた無負荷時の計量データの固有変動量が、交換閾値よりも小さい場合であったとき、針交換すべきであると自己診断する交換診断手段を備えることを特徴とする請求項１に記載の除電機能付き電子天秤。 It is provided with an exchange diagnostic means for self-diagnosis that the needle should be exchanged when the inherent variation amount of the measurement data at no load obtained by the needle deterioration evaluation means is smaller than the exchange threshold. The electronic balance with a charge eliminating function according to claim 1.

前記針劣化評価手段で得られた無負荷時の計量データの固有変動量が、故障閾値よりも大きい場合であったとき、装置故障であると自己診断する故障診断手段を備えることを特徴とする請求項１に記載の除電機能付き電子天秤。 The apparatus includes a failure diagnosis means for self-diagnosis of a device failure when the inherent variation amount of the measurement data at no load obtained by the needle deterioration evaluation means is greater than a failure threshold. The electronic balance with a charge eliminating function according to claim 1.

前記交換診断手段、前記清掃診断手段、前記故障診断手段の後に、再度前記針劣化評価手段により無負荷時の計量データの固有変動量を求め、再度前記交換診断手段、前記清掃診断手段、前記故障診断手段を行う効果確認手段を備えることを特徴とする請求項２〜４のいずれかに記載の除電機能付き電子天秤。 After the replacement diagnostic unit, the cleaning diagnostic unit, and the failure diagnostic unit, the needle deterioration evaluating unit again obtains an inherent variation amount of the weighing data at the time of no load, and again, the replacement diagnostic unit, the cleaning diagnostic unit, and the failure The electronic balance with a charge eliminating function according to claim 2, further comprising an effect confirmation unit that performs a diagnosis unit.

前記除電針に電圧を印加した電圧印加積算時間を計測・評価する積算時間評価手段を備え、基準積算時間に対し、電圧印加積算時間が基準積算時間以上に長くなった場合、前記針劣化評価手段を自動で行うことを特徴とする請求項１〜５のいずれかに記載の除電機能付き電子天秤。 An integration time evaluation unit that measures and evaluates a voltage application integration time in which a voltage is applied to the static elimination needle is provided, and when the voltage application integration time becomes longer than the reference integration time with respect to the reference integration time, the needle deterioration evaluation unit The electronic balance with a charge eliminating function according to claim 1, wherein the electronic balance is automatically performed.

前記針劣化評価手段を、前記除電針に対し単極ずつ行うことを特徴とする請求項１〜６のいずれかに記載の除電機能付き電子天秤。 The electronic balance with a static elimination function according to any one of claims 1 to 6, wherein the needle deterioration evaluation means is performed on each of the static elimination needles by a single pole.