JPS645641B2 - - Google Patents
Info
- Publication number
- JPS645641B2 JPS645641B2 JP3584481A JP3584481A JPS645641B2 JP S645641 B2 JPS645641 B2 JP S645641B2 JP 3584481 A JP3584481 A JP 3584481A JP 3584481 A JP3584481 A JP 3584481A JP S645641 B2 JPS645641 B2 JP S645641B2
- Authority
- JP
- Japan
- Prior art keywords
- density
- balance
- sample
- load
- atmospheric
- 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
- 238000005259 measurement Methods 0.000 claims description 9
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 230000035945 sensitivity Effects 0.000 claims description 3
- 238000001739 density measurement Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000005484 gravity 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)
- Analysing Materials By The Use Of Radiation (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.
大気中で行う質量測定では、物体は空気の浮力
を受け、試料の密度が天びんの較正用分銅の密度
と異なる場合、真の質量が得られない。そこで、
正確な測定値を得るには浮力補正が必要になる。
特に、試料密度が小さい場合、質量の精密測定の
場合、この空気の浮力の補正が重要である。 When measuring mass in the atmosphere, the object is subject to the buoyancy of the air, and if the density of the sample differs from the density of the balance's calibration weight, the true mass will not be obtained. Therefore,
Buoyancy correction is required to obtain accurate measurements.
Particularly when the sample density is low and for accurate mass measurement, correction of this air buoyancy is important.
従来の電子天びんでは、試料密度の違い、大気
密度の変化、さらに天候状態によつて測定値が変
動する欠点があつた。この欠点は、上記空気の浮
力に起因するものであり、測定者が計算式などに
より補正していた。従来の電子天びんにおいて、
たとえば密度１ｇ／cm3の試料100ｇを測定する場
合、密度８ｇ／cm3の分銅を用いると、空気の密度
を0.0012ｇ／cm3として約105mgの浮力を受け、真
の値より小さい測定値となつた。また、その測定
時に、大気圧が２％上昇したとすれば、空気の密
度も約２％大きくなるから、浮力も２％増え、さ
らに真の値より約2.1mg小さい測定値となつた。 Conventional electronic balances have the disadvantage that measured values fluctuate due to differences in sample density, changes in atmospheric density, and weather conditions. This defect is due to the buoyancy of the air, and was corrected by the measurer using a calculation formula. In conventional electronic balances,
For example, when measuring 100 g of a sample with a density of 1 g/cm 3 and using a weight with a density of 8 g/cm 3 , it will receive a buoyant force of approximately 105 mg, assuming the density of air is 0.0012 g/cm 3 , and the measured value will be smaller than the true value. Summer. Also, if the atmospheric pressure rose by 2% at the time of the measurement, the density of the air would also increase by about 2%, so the buoyancy would also increase by 2%, and the measured value would be about 2.1mg smaller than the true value.
この発明の目的は、上記従来の欠点を解消し、
空気の浮力による測定値の誤差を補正し、真の質
量を測定することができる電子天びんを提供する
ことにある。 The purpose of this invention is to eliminate the above-mentioned conventional drawbacks,
An object of the present invention is to provide an electronic balance capable of correcting errors in measurement values due to air buoyancy and measuring true mass.
この発明は、上記目的を達成するために、分銅
の密度(d)を記憶する記憶装置と、測定すべき試料
の密度（ρS）を入力する試料密度設定手段と、体
積の異なる二物体を平衡はりの両端に設けてこれ
を既知の空気密度のもとでバランスさせ且つ上記
試料測定時に生じたアンバランスによる力(F)を測
定する大気密度センサと、その大気密度センサに
より測定された力(F)より大気密度（ρA）を算出す
る演算手段と、上記試料の密度（ρS）、上記分銅
の密度(d)、上記大気密度（ρA）の値を用いて荷重
―電気変換装置の出力値に対して空気の浮力の補
正を演算する演算手段を有することを特徴として
いる。 In order to achieve the above object, the present invention provides a storage device for storing the density (d) of a weight, a sample density setting means for inputting the density (ρ S ) of the sample to be measured, and two objects having different volumes. Atmospheric density sensors installed at both ends of the balance beam to balance it under known air density and measure the force (F) due to the unbalance generated during the sample measurement, and the force measured by the atmospheric density sensor. Load-electrical conversion using calculation means for calculating the atmospheric density (ρ A ) from (F), the density of the sample (ρ S ), the density of the weight (d), and the atmospheric density (ρ A ). It is characterized by having a calculation means for calculating a correction for air buoyancy with respect to the output value of the device.
この発明で真の質量Ｗを求める上記浮力補正の
演算には、下の補正式(1)、あるいはその近似式(2)
などを用いる。 In the calculation of the buoyancy correction described above to obtain the true mass W in this invention, the following correction formula (1) or its approximate formula (2) is used.
etc.
Ｗ＝ｗ・ρS／ｄ・ｄ−ρA／ρS−ρA ……(1) Ｗ＝ｗ・｛１＋ρA（１／ρS−１／ｄ）｝ ……(2) ここに、ｗ：補正前の荷重値 ｄ：較正用分銅の密度 ρA：センサにより測定される大気密度 ρS試料の密度 である。 W=w・ρ S /d・d−ρ A /ρ S −ρ A ...(1) W=w・{1+ρ A (1/ρ S −1/d)} ...(2) Here, w: Load value before correction d: Density of calibration weight ρ A : Atmospheric density measured by the sensor ρ S is the density of the sample.
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図に全体構成のブロツク図を示す。 Figure 1 shows a block diagram of the overall configuration.
荷重―電気変換装置１は試料による荷重を測定
し、その荷重に対応したデジタル信号を風袋引用
演算部２に出力する。風袋引用演算部２は風袋値
を記憶し、荷重―電気変換装置１の出力からその
風袋値を減算する。その風袋引操作は天びんに設
けたスイツチ６によつて行われる。試料密度設定
器４は、キーボードよりなり試料密度ρSが入力設
定される。大気密度測定部５は測定時における大
気密度ρAを設定し、算出して演算部３へ入力す
る。はかり感度の較正に用いる分銅の密度ｄは予
め演算部３のメモリに記憶されている。演算部３
は風袋引用演算部２の出力ｗ、試料密度設定器４
による試料密度ρS、および大気密度測定部５の出
力ρAを入力し、(1)式あるいは(2)式に基づいて空気
浮力の補正演算を行う。浮力補正用演算部３の出
力は表示装置７などへ出力され、表示される。 The load-electricity converter 1 measures the load caused by the sample and outputs a digital signal corresponding to the load to the tare quotation calculation section 2. The tare quotation calculation unit 2 stores the tare value and subtracts the tare value from the output of the load-electricity converter 1. The tare operation is performed by a switch 6 provided on the balance. The sample density setting device 4 consists of a keyboard, and the sample density ρ S is input and set. The atmospheric density measurement section 5 sets the atmospheric density ρ A at the time of measurement, calculates it, and inputs it to the calculation section 3 . The density d of the weight used for calibrating the scale sensitivity is stored in advance in the memory of the calculation unit 3. Arithmetic unit 3
is the output w of the tare quotation calculation section 2, and the sample density setting device 4
The sample density ρ S and the output ρ A of the atmospheric density measurement unit 5 are input, and the air buoyancy correction calculation is performed based on equation (1) or equation (2). The output of the buoyancy correction calculation unit 3 is output to a display device 7 or the like and displayed.
浮力補正用演算部３は、風袋引用演算部２およ
び大気密度測定部５の演算とともに、マイクロコ
ンピユータにより実施することができる。 The buoyancy correction calculation section 3 can be executed by a microcomputer together with the calculations of the tare quotation calculation section 2 and the atmospheric density measurement section 5.
第２図に大気密度センサ５の一実施例を示す。
はり１２が支点１３により支持され、はり１２の
一端に体積が比較的大きな球体１０を固定し、は
り１２の他端部に調節可能なバランスウエイト１
１を設け、はり１２の定点に作用する力Ｆを検出
するための荷重センサ１４が設けられいてる。球
体１０とバランスウエイト１１に作用する力が完
全にバランスしているときは荷重センサ１４に働
く力Ｆは零であるが、アンバランスが生ずるとそ
のアンバランスの大きさに応じた力Ｆが生じる。 FIG. 2 shows an embodiment of the atmospheric density sensor 5.
A beam 12 is supported by a fulcrum 13, a relatively large sphere 10 is fixed to one end of the beam 12, and an adjustable balance weight 1 is attached to the other end of the beam 12.
1, and a load sensor 14 for detecting a force F acting on a fixed point of the beam 12. When the forces acting on the sphere 10 and the balance weight 11 are perfectly balanced, the force F acting on the load sensor 14 is zero, but when an imbalance occurs, a force F is generated depending on the magnitude of the imbalance. .
図示のように、球体１０およびバランスウエイ
ト１１の重心と支点１３の距離をl1，l2とし、荷
重センサの検出点と支点１３の距離をl3とし、球
体１０の体積をV1、バランスウエイト１１の体
積をV2とする。いま仮に真空中でバランス調整
を行つたとすれば、その後、大気中に戻したいと
き、V1＞V2であれば球体１０の方が軽くなり、
荷重センサ１４が正の力Ｆを検出する。この状態
の大気密度ρAは、
ρA＝l3／V1l1―V2l2Ｆ ……(3)
により与えられる。バランス調整を真空中でなく
既知の大気密度ρpのもとで行つた場合は測定時の
大気密度ρAと既知の大気密度ρpの差ρΔによりア
ンバランスが生ずるから
ρΔ＝ρA−ρp＝l3／V1l1−V2l2Ｆ ……(4)
これより
ρA＝ρΔ＋ρp＝l3／V1l1−V2l2Ｆ＋ρp ……(5)
となる。 As shown in the figure, the distances between the centers of gravity of the sphere 10 and the balance weight 11 and the fulcrum 13 are l 1 and l 2 , the distance between the detection point of the load sensor and the fulcrum 13 is l 3 , the volume of the sphere 10 is V 1 , and the balance Let the volume of the weight 11 be V2 . If we were to adjust the balance in a vacuum, then when we want to return it to the atmosphere, if V 1 > V 2 , the sphere 10 will be lighter;
Load sensor 14 detects positive force F. The atmospheric density ρ A in this state is given by ρ A = l 3 /V 1 l 1 −V 2 l 2 F (3). If balance adjustment is performed under a known atmospheric density ρ p instead of in a vacuum, an imbalance will occur due to the difference ρΔ between the atmospheric density ρ A at the time of measurement and the known atmospheric density ρ p , so ρΔ = ρ A − ρ p = l 3 /V 1 l 1 −V 2 l 2 F ... (4) From this, ρ A = ρΔ + ρ p = l 3 /V 1 l 1 −V 2 l 2 F + ρ p ... (5).
大気密度センサ５と、その出力値に基づき大気
密度ρAを算出する演算部により大気密度測定部５
が構成される。 Atmospheric density measuring section 5 is operated by an atmospheric density sensor 5 and a calculation section that calculates atmospheric density ρ A based on the output value of the atmospheric density sensor 5.
is configured.
さらに、第３図に示す他の変形実施例を説明す
る。第１図と同一部分は同一番号を付し、説明を
省略する。 Furthermore, another modified embodiment shown in FIG. 3 will be described. Components that are the same as those in FIG. 1 are designated by the same numbers, and their explanation will be omitted.
表示装置７の入力する信号を、風袋引用演算部
２の出力信号と浮力補正用演算部３の出力信号の
どちらかに切り換える切換スイツチ９が設けられ
ている。この切換スイツチ９の操作によつて、浮
力補正がなされない測定値の表示と、浮力補正用
演算部３を経て浮力補正がなされた測定値の表示
の二系列表示が得られる。この二系列表示によつ
て、浮力補正されない従来の天びんで測定した場
合と浮力補正した場合の測定値の比較が行え、使
用者にとつて便利である。 A changeover switch 9 is provided for switching the signal input to the display device 7 to either the output signal of the tare quotation calculation section 2 or the output signal of the buoyancy correction calculation section 3. By operating the changeover switch 9, two series of displays are obtained: a display of measured values without buoyancy correction and a display of measured values subjected to buoyancy correction via the buoyancy correction calculation section 3. This two-line display is convenient for the user, as it is possible to compare the values measured with a conventional balance without buoyancy correction and those measured with buoyancy correction.
また、切換スイツチを設けず、風袋引用演算部
２の出力と、浮力補正用演算３の出力を同時に表
示させてもよい。 Alternatively, the output of the tare weight quotation calculation section 2 and the output of the buoyancy correction calculation 3 may be displayed simultaneously without providing a changeover switch.
この発明によれば、試料密度および大気密度が
変わつても、つねに空気の浮力の補正がなされる
ので、真の質量を計測する電子天びんが得られ
る。また、自動感度較正機構を内蔵した電子天び
んに適用して、より高精度な質量計測を行なう電
子天びんを得ることができる。 According to this invention, even if the sample density and atmospheric density change, the buoyancy of air is always corrected, so an electronic balance that measures true mass can be obtained. Further, by applying the present invention to an electronic balance having a built-in automatic sensitivity calibration mechanism, it is possible to obtain an electronic balance that performs mass measurement with higher accuracy.
第１図はこの発明の実施例を示すブロツク図、
第２図はこの発明の大気密度センサの構成図、第
３図はこの発明の変形実施例を示すブロツク図で
ある。
１……荷重―電気変換装置、３……浮力補正用
演算部、４……試料密度設定器、５……大気密度
測定部、７……表示装置。
FIG. 1 is a block diagram showing an embodiment of this invention.
FIG. 2 is a block diagram of an atmospheric density sensor according to the present invention, and FIG. 3 is a block diagram showing a modified embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Load-electric conversion device, 3... Buoyancy correction calculation unit, 4... Sample density setting device, 5... Atmospheric density measurement unit, 7... Display device.
Claims (1)
用いる分銅と、荷重に対応したデジタル出力を表
示する表示装置を備えた電子天びんにおいて、上
記分銅の密度(d)を記憶する記憶装置と、測定すべ
き試料の密度（ρS）を入力する試料密度設定手段
と、体積の異なる二物体を平衡はりの両端に設け
てこれを既知の空気密度のもとでバランスさせ且
つ上記試料測定時に生じたアンバランスによる力
(F)を測定する大気密度センサと、その大気密度セ
ンサにより測定された力(F)より大気密度（ρA）を
算出する演算手段と、上記試料の密度（ρS）、上
記分銅の密度(d)、上記大気密度（ρA）の値を用い
て上記荷重―電気変換装置の出力値に対して空気
の浮力の補正を演算する演算手段を有する電子天
びん。1. In an electronic balance equipped with a load-electrical conversion device, a weight used for calibrating balance sensitivity, and a display device that displays a digital output corresponding to the load, a storage device that stores the density (d) of the weight, and a measurement A sample density setting means for inputting the density of the sample to be measured (ρ S ), and two objects with different volumes are provided at both ends of the balance beam to balance them under a known air density, and Force due to imbalance
(F), a calculation means for calculating the atmospheric density (ρ A ) from the force (F) measured by the atmospheric density sensor, and the density of the sample (ρ S ) and the density of the weight. (d) An electronic balance having calculation means for calculating a correction for air buoyancy with respect to the output value of the load-to-electrical conversion device using the value of the atmospheric density (ρ A ).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3584481A JPS57149925A (en) | 1981-03-11 | 1981-03-11 | Electronic balance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3584481A JPS57149925A (en) | 1981-03-11 | 1981-03-11 | Electronic balance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57149925A JPS57149925A (en) | 1982-09-16 |
| JPS645641B2 true JPS645641B2 (en) | 1989-01-31 |
Family
ID=12453287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3584481A Granted JPS57149925A (en) | 1981-03-11 | 1981-03-11 | Electronic balance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57149925A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63145922A (en) * | 1986-12-10 | 1988-06-18 | Ee & D:Kk | Measuring apparatus having air density measuring mechanism |
| JPS63193021A (en) * | 1987-02-06 | 1988-08-10 | Ee & D:Kk | Remote operation type electronic balance |
-
1981
- 1981-03-11 JP JP3584481A patent/JPS57149925A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57149925A (en) | 1982-09-16 |
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