JPH0310891B2 - - Google Patents
Info
- Publication number
- JPH0310891B2 JPH0310891B2 JP2043481A JP2043481A JPH0310891B2 JP H0310891 B2 JPH0310891 B2 JP H0310891B2 JP 2043481 A JP2043481 A JP 2043481A JP 2043481 A JP2043481 A JP 2043481A JP H0310891 B2 JPH0310891 B2 JP H0310891B2
- Authority
- JP
- Japan
- Prior art keywords
- pendulum
- output
- section
- mass
- load
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000001514 detection method Methods 0.000 claims description 19
- 230000005284 excitation Effects 0.000 claims description 5
- 238000005259 measurement Methods 0.000 claims description 3
- 230000001133 acceleration Effects 0.000 description 14
- 230000005484 gravity Effects 0.000 description 10
- 238000006073 displacement reaction Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000009434 installation Methods 0.000 description 4
- 230000010355 oscillation Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01G—WEIGHING
- G01G23/00—Auxiliary devices for weighing apparatus
- G01G23/01—Testing or calibrating of weighing apparatus
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Balance (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Description
【発明の詳細な説明】 この発明は電子天びんに関する。[Detailed description of the invention] This invention relates to electronic balances.
従来の電子天びんは一般に重力を利用した力の
計測器であるので、天びんの使用場所における重
力の影響を受ける欠点があつた。 Since conventional electronic balances are generally force measuring instruments that utilize gravity, they have the disadvantage of being affected by gravity at the location where the balance is used.
すなわち、重力の加速度は緯度および高度によ
つて異なり、しかもその値は連続的に変化する。
従つて天びんの設置場所を変更するごとに、質量
既知の分銅等を用いて較正しなければ正確な質量
の測定ができなかつた。ここで、例えばひよう量
200ｇ、読取限度0.1mgの高分解能の天びんでは、
北海道と鹿児島で続取限度の2000倍にも及ぶ差が
生じ、設置場所を少し変更するだけでも較正しな
ければ誤差が生じる。 That is, the acceleration of gravity varies depending on latitude and altitude, and its value changes continuously.
Therefore, each time the location of the balance is changed, accurate mass measurements cannot be made unless calibration is performed using a weight or the like whose mass is known. Here, for example, the weight
With a high resolution balance of 200g and a reading limit of 0.1mg,
There is a difference of 2,000 times in the takeover limit between Hokkaido and Kagoshima, and even a slight change in the installation location will cause an error unless calibration is performed.
本発明はこの点に鑑みてなされたもので、いか
なる場所で使用してもその場所の重力の加速度の
影響を全く受けることなく、従つてその使用場所
の緯度や高度等が不明であつても、あるいはその
場所の重力の加速度が不明であつても、電源を投
入するだけで直ちに試料の質量を正確に計測する
ことにのできる電子天びんの提供を目的としてい
る。 The present invention has been made in view of this point, and no matter where it is used, it will not be affected by the acceleration of gravity at that place, and therefore, even if the latitude, altitude, etc. of the place of use are unknown. The purpose of the present invention is to provide an electronic balance that can accurately measure the mass of a sample immediately by simply turning on the power, even if the gravitational acceleration at that location is unknown.
この目的を達成するため、本発明の電子天びん
は、皿上の荷重に対応する電気信号を出力する荷
重測定部と、振動自在に支承された所定長さの振
り子と、当該天びんの電源投入により起動して振
り子に振動を与える励振回路と、振り子の振動周
期を刻々と検出して出力する振動周期検出手段
と、その振動周期検出手段の出力と荷重検出部の
出力を用いて皿上の試料の質量を算出する演算部
と、その算出結果を表示する表示部を備えたこと
によつて特徴づけられる。 To achieve this purpose, the electronic balance of the present invention includes a load measuring section that outputs an electric signal corresponding to the load on the pan, a pendulum of a predetermined length that is supported so as to be able to vibrate, and a An excitation circuit that starts to vibrate the pendulum, an oscillation period detection means that detects and outputs the oscillation period of the pendulum every moment, and an output of the oscillation period detection means and an output of the load detection section to detect the sample on the dish. It is characterized by having a calculation unit that calculates the mass of the vehicle, and a display unit that displays the calculation result.
ここで、振り子の振動周期はその設定場所にお
ける重力の加速度に相関するから、荷重測定部出
力と併せて試料の質量を算出できる。 Here, since the vibration period of the pendulum correlates with the acceleration of gravity at the setting location, the mass of the sample can be calculated in conjunction with the output of the load measuring section.
なお、本発明の荷重測定部としては、ロードセ
ル、電磁力平衡型や弦振動式の力センサ等によつ
て実施することができる。 The load measuring section of the present invention can be implemented using a load cell, an electromagnetic force balance type force sensor, a string vibration type force sensor, or the like.
以下、この発明の実施例を図面に基づき説明す
る。 Embodiments of the present invention will be described below based on the drawings.
第１図は本発明実施例の構成を示すブロツク図
である。荷重検出部１は皿２上の試料Ｓの重量Ｗ
に対応する電圧信号を出力してＶ−Ｆコンバータ
３に供給する。Ｖ−Ｆコンバータ３は入力信号電
圧に比例した周波数信号を出力する。このＶ−Ｆ
コンバータ３の出力周波数をＦとし、この電子天
びんの設置場所における重力の加速度をｇ、試料
の質量をＭとすると、
Ｆ＝KW＝WMg ……(1)
の関係が成立する。ここで、Ｋは比例定数であ
る。 FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. The load detection unit 1 detects the weight W of the sample S on the plate 2.
A voltage signal corresponding to the voltage signal is output and supplied to the V-F converter 3. The V-F converter 3 outputs a frequency signal proportional to the input signal voltage. This V-F
If the output frequency of the converter 3 is F, the acceleration of gravity at the location where the electronic balance is installed is g, and the mass of the sample is M, then the relationship F=KW=WMg...(1) holds true. Here, K is a proportionality constant.
このＶ−Ｆコンバータ３の出力は、以下に述べ
る重力加速度検出部５の出力とともに演算部４に
入力される。 The output of this V-F converter 3 is input to the calculation section 4 together with the output of the gravitational acceleration detection section 5, which will be described below.
重力加速度検出部５は、振り子５１とその励振
回路、および振り子５１の振動周期の検出回路に
よつて構成されている。振り子５１は、天びんケ
ース内における固定部位に一端が揺動自在に支承
され、先端に永久磁石５４を設けてなつている。
この振り子５１の振動方向の片側には駆動コイル
５２が、他の側には変位検出コイル５３が配設さ
れており、振り子５１はこれら両コイル間を往復
振動する。すなわち、駆動コイル５２に電流を流
すことによつて永久磁石５４が吸引もしくは反発
され、これによつて振り子５１が振動を開始す
る。この振り子５１の振動による永久磁石５４の
変位により、変位検出コイル５３には起電力が誘
起される。この起電力は増幅５５によつて増幅さ
れた後、駆動コイル５２にフイードバツクされ
る。これよにつて振り子５１は自励的に単振動を
継続することになる。つまり、変位検出コイル５
３、増幅器５５および駆動コイル５２は振り子５
１の励振回路を構成している。そして、増幅器５
５の出力は、振り子５１の振動と同期した周期で
変化することになり、この出力は振動周期検出信
号として演算部４に入力される。 The gravitational acceleration detection section 5 includes a pendulum 51, its excitation circuit, and a detection circuit for the vibration period of the pendulum 51. One end of the pendulum 51 is swingably supported at a fixed portion within the balance case, and a permanent magnet 54 is provided at the tip.
A drive coil 52 is disposed on one side of the pendulum 51 in the vibration direction, and a displacement detection coil 53 is disposed on the other side, and the pendulum 51 reciprocates between these two coils. That is, by passing a current through the drive coil 52, the permanent magnet 54 is attracted or repelled, thereby causing the pendulum 51 to start vibrating. The displacement of the permanent magnet 54 due to the vibration of the pendulum 51 induces an electromotive force in the displacement detection coil 53. This electromotive force is amplified by an amplifier 55 and then fed back to the drive coil 52. As a result, the pendulum 51 continues its simple harmonic motion in a self-excited manner. In other words, the displacement detection coil 5
3. The amplifier 55 and the drive coil 52 are connected to the pendulum 5
1 excitation circuit. And amplifier 5
The output of the pendulum 51 changes at a period synchronized with the vibration of the pendulum 51, and this output is input to the calculation unit 4 as a vibration period detection signal.
振り子５１の単振動の周期Ｔは、振り子５１の
長さをｌ、この天びんの設置場所における重力の
加速度をｇとすると、
Ｔ＝2π√ ……(2)
で表される。 The period T of the simple harmonic motion of the pendulum 51 is expressed as T=2π√ (2) where the length of the pendulum 51 is l and the acceleration of gravity at the location where the balance is installed is g.
演算部４は、この振動周期Ｔの検出信号とＶ−
Ｆコンバータ３からの周波数Ｆの出力信号を入力
して、次の演算によつて試料Ｓの質量Ｍを算出
し、表示装置６にその結果を供給し、表示する。 The calculation unit 4 calculates the detection signal of this vibration period T and V-
The output signal of frequency F from the F converter 3 is input, the mass M of the sample S is calculated by the following calculation, and the result is supplied to the display device 6 and displayed.
Ｍ＝K1FT2 ……(3) ただしK1＝１／4π2lK すなわち(2)式から、 T2＝4π2l／ｇ ……(5) (1)式と(5)式から FT2＝4π2lK・Ｍ ……(6) となり、(3)式が成立する。 M=K 1 FT 2 ...(3) However, K 1 = 1/4π 2 lK That is, from equation (2), T 2 = 4π 2 l/g ...(5) From equations (1) and (5) FT 2 =4π 2 lK・M ...(6), and formula (3) holds true.
次に各部の動作を具体的に説明する。 Next, the operation of each part will be specifically explained.
天びんに電源が供給されると、駆動コイル５２
を始めとする励振回路が作動して振り子５１が単
振動を開始し、天びんの設置場所に応じた周期Ｔ
の検出信号が演算部４に刻々と供給される。その
状態で皿２上に試料Ｓを載せると、Ｖ−Ｆコンバ
ータ３にはその重量Ｗに応じた電圧信号が供給さ
れ、それに相当する周波数Ｆの信号が演算部４に
供給される。演算部４は、周期Ｔに対応してＦを
計数し、Ｔの２乗とＦを乗算して更に定数K1を
乗じることによつて(3)式のＭを求め、表示装置６
に供給する。表示装置６には、従つて、いかなる
場所で使用しても、電源を投入して試料Ｓを皿２
上に載せるだけで、重力の加速度に影響されない
正しい質量Ｍが直ちに表示されることになる。 When power is supplied to the balance, the drive coil 52
When the excitation circuit including the
The detection signal is supplied to the calculation unit 4 every moment. When the sample S is placed on the plate 2 in this state, a voltage signal corresponding to the weight W of the sample S is supplied to the V-F converter 3, and a signal of a frequency F corresponding to the voltage signal is supplied to the calculation section 4. The calculation unit 4 counts F corresponding to the period T, multiplies the square of T by F, and further multiplies the constant K1 to obtain M in equation (3), and displays the result on the display device 6.
supply to. Therefore, no matter where the display device 6 is used, it is possible to turn on the power and place the sample S on the dish 2.
Just by placing it on top, the correct mass M that is not affected by the acceleration of gravity will be displayed immediately.
第２図は本発明の他の実施例の構成を示すブロ
ツク図である。この図においては第１図と同一部
分は同一番号を付し説明を省略する。この変形実
施例では荷重検出部１の出力がデジタル信号とし
て演算部２２に入力され、周期Ｔに対応したカウ
ント数を用いて質量Ｍが求められる。 FIG. 2 is a block diagram showing the configuration of another embodiment of the present invention. In this figure, parts that are the same as those in FIG. 1 are given the same numbers and explanations will be omitted. In this modified embodiment, the output of the load detection section 1 is inputted as a digital signal to the calculation section 22, and the mass M is determined using the count number corresponding to the period T.
Ａ／Ｄ変換器２１によつてデジタル信号化され
た荷重検出部１の出力Ｆは演算部２２に入力され
る。基準クロツク信号発生器２４は一定の周波数
f0の基準クロツク信号をカウンター２３に供給す
る。重力加速度測定部５の周期Ｔのパルス信号出
力はカウンター２３のリセツト信号として入力さ
れる。すなわち、カウンター２３は基準クロツク
信号を上記パルス信号によつてリセツトしてカウ
ント数Ｎ（＝f0T）を計数し、演算部２２に出力
する。演算部２２は次の(7)式に従い、質量Ｍを演
算する。 The output F of the load detection section 1, which is converted into a digital signal by the A/D converter 21, is input to the calculation section 22. Reference clock signal generator 24 has a constant frequency.
A reference clock signal of f 0 is supplied to the counter 23. A pulse signal output with a period T from the gravitational acceleration measuring section 5 is inputted as a reset signal to the counter 23. That is, the counter 23 resets the reference clock signal using the pulse signal, counts the count number N (=f 0 T), and outputs it to the calculation section 22. The calculation unit 22 calculates the mass M according to the following equation (7).
(3)式及びＮ＝f0Tから Ｍ＝K1FT2＝K2FN2 ……(7) ここで、K2＝１／（4π2lKf0 2）である。 From equation (3) and N=f 0 T, M=K 1 FT 2 =K 2 FN 2 (7) where K 2 =1/(4π 2 lKf 0 2 ).
すなわち、演算部２２はカウント数Ｎの２乗と
Ｆを乗算し、さらに定数K2を乗じることにより
(7)式の質量Ｍを求め、表示装置６に出力する。こ
の実施例においても同様に、設置場所のいかんを
問わず電源を投入して試料Ｓを皿２上に載せるだ
けで、表示装置６に直ちに正しい質量Ｍが表示さ
れる。 That is, the calculation unit 22 multiplies the square of the count number N by F, and further multiplies it by a constant K2 .
The mass M in equation (7) is determined and output to the display device 6. Similarly, in this embodiment, regardless of the installation location, just by turning on the power and placing the sample S on the plate 2, the correct mass M is immediately displayed on the display device 6.
以上説明したように、本発明によれば、振り子
を自励的に単振動させてその周期を刻々と検出す
ることによつて、設置場所の重力の加速度を自動
的に測定しつつ、その測定値と荷重測定値を用い
て試料の質量を刻々と算出・表示するから、いか
なる場所に設置しても重力の加速度の影響による
誤差の較正作業や、あるいは他の設定、調整作業
等を全く行うことなく、電源を投入するだけで直
ちに正確な質量を表示することができ、特に高分
解能の天びんに対してその効果は大きい。また、
本発明によれば、例えば船舶内等の刻々と移動す
る設置場所等のように、加速度が経時的に変化す
るような場所において使用しても、これに影響さ
れることなく、常に正しい質量を得ることができ
るという効果もある。 As explained above, according to the present invention, by causing the pendulum to self-excited simple harmonic motion and detecting its period moment by moment, the acceleration of gravity at the installation location can be automatically measured. Since the mass of the sample is calculated and displayed moment by moment using the value and load measurement value, no matter where it is installed, there is no need to calibrate errors due to the effects of gravitational acceleration or perform other settings and adjustments. It is possible to display accurate mass immediately by simply turning on the power, and this is especially effective for high-resolution balances. Also,
According to the present invention, even when used in a place where acceleration changes over time, such as an installation place that moves from moment to moment, such as inside a ship, the correct mass is always maintained without being affected by this. There is also the effect that you can get it.
第１図は本発明実施例の構成を示すブロツク
図、第２図は本発明の他の実施例の構成を示すブ
ロツク図である。
１……荷重検出部、４，２２……演算部、５…
…重力加速度測定部、５１……振り子、５２……
駆動コイル、５３……変位検出コイル、５４……
永久磁石。
FIG. 1 is a block diagram showing the structure of an embodiment of the invention, and FIG. 2 is a block diagram showing the structure of another embodiment of the invention. 1...Load detection section, 4, 22...Calculation section, 5...
...Gravity acceleration measuring section, 51... Pendulum, 52...
Drive coil, 53... Displacement detection coil, 54...
permanent magnet.
Claims (1)
重測定部と、振動自在に支承された所定長さの振
り子と、当該天びんの電源投入により起動し上記
振り子に単振動を与える励振回路と、上記振り子
の振動周期を刻々と検出して出力する振動周期検
出手段と、その振動周期検出手段の出力と上記荷
重測定部の出力を用いて皿上の試料の質量を算出
する演算部と、その演算部による算出結果を表示
する表示部を備えてなる電子天びん。1. A load measuring unit that outputs an electrical signal corresponding to the load on the pan, a pendulum of a predetermined length that is supported so as to be able to vibrate, and an excitation circuit that is activated when the balance is powered on and gives simple harmonic motion to the pendulum; a vibration period detection means for detecting and outputting the vibration period of the pendulum moment by moment; a calculation section for calculating the mass of the sample on the plate using the output of the vibration period detection means and the output of the load measurement section; An electronic balance that is equipped with a display section that displays calculation results from a calculation section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2043481A JPS57135323A (en) | 1981-02-13 | 1981-02-13 | Electronic balance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2043481A JPS57135323A (en) | 1981-02-13 | 1981-02-13 | Electronic balance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57135323A JPS57135323A (en) | 1982-08-20 |
| JPH0310891B2 true JPH0310891B2 (en) | 1991-02-14 |
Family
ID=12026931
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2043481A Granted JPS57135323A (en) | 1981-02-13 | 1981-02-13 | Electronic balance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57135323A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0540997U (en) * | 1991-03-29 | 1993-06-01 | 株式会社ガステツク | Gas detection alarm |
| DE4320892A1 (en) * | 1993-06-23 | 1995-01-05 | Mettler Toledo Albstadt Gmbh | Libra |
-
1981
- 1981-02-13 JP JP2043481A patent/JPS57135323A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57135323A (en) | 1982-08-20 |
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