JPS6126912Y2 - - Google Patents
Info
- Publication number
- JPS6126912Y2 JPS6126912Y2 JP889281U JP889281U JPS6126912Y2 JP S6126912 Y2 JPS6126912 Y2 JP S6126912Y2 JP 889281 U JP889281 U JP 889281U JP 889281 U JP889281 U JP 889281U JP S6126912 Y2 JPS6126912 Y2 JP S6126912Y2
- Authority
- JP
- Japan
- Prior art keywords
- cylindrical resonator
- fluid
- measured
- resonator
- cover
- 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
- 239000012530 fluid Substances 0.000 claims description 17
- 238000001514 detection method Methods 0.000 claims description 11
- 230000005284 excitation Effects 0.000 claims description 9
- 238000010586 diagram Methods 0.000 description 4
- 238000010276 construction Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 1
- 238000012806 monitoring device Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Landscapes
- Measuring Fluid Pressure (AREA)
Description
【考案の詳細な説明】
本考案は、円筒共振式の密度計に関するもので
ある。更に詳しくは、本考案は、構成が簡単で、
かつ動作が安定な主として卓上用として有効な密
度計に関するものである。[Detailed Description of the Invention] The present invention relates to a cylindrical resonance type density meter. More specifically, the present invention is simple in construction,
The present invention also relates to a density meter that is stable in operation and is effective mainly for desktop use.
第１図は従来公知のこの種の密度計の一例を示
す構成図である。この装置は、特公昭51−16794
号公報に記載されているものであつて、測定され
るべき流体が内側および外側を通過するようにな
つている円筒共振子１と、この円筒共振子１を励
振してこれをある共振周波数で振動させるための
駆動手段２と、円筒共振子１の振動数を検出する
検出手段３と、検出手段３からの信号を入力する
とともに駆動手段２に励振信号を与える増巾器４
と、共振周波数を監視する監視装置５とを備えて
いる。この装置は、円筒共振子１の内側、外側を
通過する流体が流れを阻害されることなく直進す
るように構成されている点にひとつの特徴があ
り、流れに対して殆んど抵抗がなく設置できる等
の利点がある。しかしながら、この装置において
は、円筒共振子１の内側および外側に被測定流体
が流れるために、振動エネルギーが外壁を通して
流出し、円筒共振子のＱが低くなつて、発振周波
数の安定度が悪く、精度が悪い欠点がある。ま
た、被測定流体が円筒共振子の外側に付着するよ
うな場合、その洗浄が困難である等、取扱いが不
便である。 FIG. 1 is a block diagram showing an example of a conventionally known density meter of this type. This device was manufactured by the Special Publication Publication No. 51-16794.
The cylindrical resonator 1, which is described in the above publication, has a cylindrical resonator 1 in which a fluid to be measured passes through inside and outside, and the cylindrical resonator 1 is excited to have a certain resonant frequency. A driving means 2 for vibrating, a detecting means 3 for detecting the frequency of the cylindrical resonator 1, and an amplifier 4 that inputs the signal from the detecting means 3 and provides an excitation signal to the driving means 2.
and a monitoring device 5 that monitors the resonance frequency. One feature of this device is that it is configured so that the fluid passing inside and outside the cylindrical resonator 1 travels straight without being hindered, and there is almost no resistance to the flow. It has the advantage of being easy to install. However, in this device, since the fluid to be measured flows inside and outside the cylindrical resonator 1, vibration energy flows out through the outer wall, the Q of the cylindrical resonator becomes low, and the stability of the oscillation frequency is poor. It has the disadvantage of poor accuracy. Furthermore, if the fluid to be measured adheres to the outside of the cylindrical resonator, it is difficult to clean it, making it inconvenient to handle.
ここにおいて、本考案は従来装置におけるこれ
らの欠点のない構成の簡単な密度計を実現しよう
とするものである。 Here, the present invention seeks to realize a simple density meter of construction that does not have these drawbacks of conventional devices.
第２図は、本考案に係る密度計の一例を示す構
成断面図、第３図は一部を断面で示す構成斜視図
である。これらの図において、１は円筒共振子
で、一端側はフランジ１１が、他端側はフランジ
１２および他端側を閉じる底部１３が設けられて
いる。そして、他端側のフランジ１２には、一端
側の開口部から入つた被測定流体が流出する貫通
孔１４が形成してある。２はフランジ１２の段部
に取付けた円筒共振子１の励振手段、３は同じく
フランジ１２の段部に取付けた円筒共振子１の振
動検出手段で、ここではいずれもPZTを用いた場
合を例示してある。４１および４２はいずれも同
〓〓〓〓
一径のカバーであつて、カバー４１は両端のフラ
ンジ部１１，１２に結合し、円筒共振子１の外側
を覆い、また、カバー４２は一端がフランジ部１
２に結合し、励振手段２および振動検出手段３に
接続されるリード線２１，３１を覆つている。カ
バー４１と円筒共振子１との間に形成される部屋
１５内は、大気圧あるいは一定圧力（真空も含
む）の気体が封入されている。 FIG. 2 is a sectional view showing an example of a density meter according to the present invention, and FIG. 3 is a perspective view showing a partially sectional view. In these figures, reference numeral 1 denotes a cylindrical resonator, which is provided with a flange 11 at one end, a flange 12 at the other end, and a bottom 13 that closes the other end. The flange 12 on the other end side is formed with a through hole 14 through which the fluid to be measured that has entered through the opening on the one end side flows out. 2 is an excitation means for the cylindrical resonator 1 attached to the step of the flange 12, and 3 is a vibration detection means for the cylindrical resonator 1 also attached to the step of the flange 12. Here, an example is shown in which PZT is used in both cases. It has been done. 41 and 42 are both the same〓〓〓〓
The cover 41 is a cover with a single diameter, and is connected to the flange portions 11 and 12 at both ends to cover the outside of the cylindrical resonator 1.
2 and covers lead wires 21 and 31 connected to the excitation means 2 and the vibration detection means 3. The chamber 15 formed between the cover 41 and the cylindrical resonator 1 is filled with gas at atmospheric pressure or constant pressure (including vacuum).
このように構成した装置において、密度測定時
には、装置を第３図に示すように被測定流体中に
挿入する。これにより、被測定流体は、先端開口
部から矢印ａに示すように、円筒共振子１の内側
に流入し、貫通孔１４から流出する。この状態
で、励振手段２、振動検出手段３を含んで形成さ
れる自励発振ループ（図示せず）によつて円筒共
振子１を円環振動させる。ここで、円筒共振子１
の共振周波数は、円筒共振子１の内側に満たされ
た被測定流体の主として密度Ｄに関連して変化す
る。なお、円筒共振子１の内側と外側の圧力差に
よる影響は、被測定流体の圧力を例えば大気圧に
等しくするとか、一定圧力に維持することにより
なくすることができ、また、温度による影響は、
円筒共振子１の材料を小さな温度弾性係数をもつ
ものとするか、あるいは温度検出手段を別に設置
して、そこからの信号を利用して補正する等し
て、無視できる。 In the device configured as described above, when measuring density, the device is inserted into the fluid to be measured as shown in FIG. 3. Thereby, the fluid to be measured flows into the inside of the cylindrical resonator 1 from the tip opening as shown by the arrow a, and flows out from the through hole 14. In this state, a self-excited oscillation loop (not shown) formed including the excitation means 2 and the vibration detection means 3 causes the cylindrical resonator 1 to vibrate in an annular manner. Here, cylindrical resonator 1
The resonance frequency changes mainly in relation to the density D of the fluid to be measured filled inside the cylindrical resonator 1. Note that the influence of the pressure difference between the inside and outside of the cylindrical resonator 1 can be eliminated by, for example, making the pressure of the fluid to be measured equal to atmospheric pressure or maintaining it at a constant pressure, and the influence of temperature can be eliminated. ,
This can be ignored by making the material of the cylindrical resonator 1 a material with a small temperature elastic coefficient, or by installing a separate temperature detection means and correcting it using the signal from the temperature detection means.
第４図は、本考案に係る密度計の電気的なブロ
ツク図である。円筒共振子１、励振手段２、振動
検出手段３および増巾器４は、図示するように閉
ループを形成するように接続されており、円筒共
振子１は円環振動を持続する。円筒共振子１の共
振周波数fdは、カウンタ５１、リニアライザ５
２、スケーラ５３を介して表示器５４に表示され
る。 FIG. 4 is an electrical block diagram of the density meter according to the present invention. The cylindrical resonator 1, the excitation means 2, the vibration detection means 3, and the amplifier 4 are connected to form a closed loop as shown, and the cylindrical resonator 1 maintains circular vibration. The resonant frequency fd of the cylindrical resonator 1 is determined by the counter 51 and the linearizer 5.
2. Displayed on the display 54 via the scaler 53.
被測定流体の密度Ｄと共振周波数fdとの関係
は、次式で表わされることが知られている。 It is known that the relationship between the density D of the fluid to be measured and the resonance frequency fd is expressed by the following equation.
たゞし、
fo：密度０（真空中）における共振周波数
Ｋ：円筒共振子１の直径、厚さ等によつて定まる
定数
このように構成した装置は、被測定流体が円筒
共振子１の内側にだけ流入する構造のために、被
測定流体の置換がスムーズであり、また、洗浄に
際しては、円筒共振子１の内側のみ行えばよいの
で容易である。また、円筒共振子１の外側は、大
気圧又は一定圧力の気体が封入されていることか
ら、音響エネルギーは外側に伝わりにくく、従つ
て、円筒共振子の音響エネルギーは主に円筒共振
子１内の被測定流体の内部損失だけで、円筒共振
子１のＱを高くでき、動作が安定となり、感度を
高くすることができる。また、全体が細長い棒状
とすることができることから、ビーカーや試験管
等に採取した被測定流体の密度測定にも適する。 However, fo: Resonant frequency at density 0 (in vacuum) K: Constant determined by the diameter, thickness, etc. of the cylindrical resonator 1 In the device configured in this way, the fluid to be measured is inside the cylindrical resonator 1. Because of the structure that only flows into the cylindrical resonator 1, replacement of the fluid to be measured is smooth, and cleaning is easy because it only needs to be done inside the cylindrical resonator 1. Furthermore, since the outside of the cylindrical resonator 1 is filled with gas at atmospheric pressure or a constant pressure, acoustic energy is difficult to transmit to the outside, and therefore the acoustic energy of the cylindrical resonator is mainly transmitted inside the cylindrical resonator 1. The Q of the cylindrical resonator 1 can be increased only by the internal loss of the fluid to be measured, the operation becomes stable, and the sensitivity can be increased. Furthermore, since the entire device can be formed into an elongated rod shape, it is suitable for measuring the density of a fluid to be measured collected in a beaker, test tube, or the like.
なお、上記の実施例では、円筒共振子１の励振
手段および振動検出手段として、PZTを用いたも
のを例示したが、電磁式や静電式の励振手段およ
び検出手段を用いるようにしてもよい。また、円
筒共振子１は両端開放の構造でもよい。また、カ
バー４２の内部には、例えば被測定流体の温度を
検出するための温度検出手段を設置するようにし
てもよい。 In addition, in the above embodiment, PZT was used as the excitation means and vibration detection means of the cylindrical resonator 1, but electromagnetic or electrostatic excitation means and detection means may also be used. . Furthermore, the cylindrical resonator 1 may have a structure with both ends open. Further, inside the cover 42, for example, a temperature detection means for detecting the temperature of the fluid to be measured may be installed.
以上説明したように、本考案によれば、構造が
簡単で、動作が安定な主として卓上用に適する密
度計が実現できる。 As explained above, according to the present invention, it is possible to realize a density meter that has a simple structure, stable operation, and is suitable mainly for desktop use.
第１図は従来公知の密度計の一例を示す構成
図、第２図は本考案に係る密度計の一例を示す構
成断面図、第３図は一部を断面で示す構成斜視
図、第４図は電気的なブロツク図である。
１……円筒共振子、１１，１２……フランジ
部、１４……貫通孔、２……励振手段、３……振
動検出手段、４……増巾器、４１，４２……カバ
ー。
〓〓〓〓
FIG. 1 is a configuration diagram showing an example of a conventionally known density meter, FIG. 2 is a configuration cross-sectional view showing an example of the density meter according to the present invention, FIG. 3 is a configuration perspective view partially shown in cross section, and FIG. The figure is an electrical block diagram. DESCRIPTION OF SYMBOLS 1... Cylindrical resonator, 11, 12... Flange part, 14... Through hole, 2... Excitation means, 3... Vibration detection means, 4... Amplifier, 41, 42... Cover. 〓〓〓〓
Claims (1)
なくとも一端が開放しておりそこから被測定流体
が流入し内部に被測定流体が満たされるようにし
た構造の円筒共振子、前記各フランジ部に結合し
前記円筒共振子の外側を覆うカバー、前記円筒共
振子を励振する励振手段、前記円筒共振子の振動
検出手段および円筒共振子の振動周波数を計数す
るカウンタを含む回路手段を具備し、前記円筒共
振子と前記カバーとの間に形成される部屋内に大
気圧又は一定圧力の気体を封入するようにした密
度計。 A cylindrical resonator having a structure in which each end has a flange part and at least one end is open so that a fluid to be measured flows in therefrom and the fluid to be measured is filled inside the resonator; circuit means including a cover for covering the outside of the cylindrical resonator, an excitation means for exciting the cylindrical resonator, a vibration detection means for the cylindrical resonator, and a counter for counting the vibration frequency of the cylindrical resonator; A density meter that seals gas at atmospheric pressure or a constant pressure in the chamber formed between the cover and the cover.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP889281U JPS6126912Y2 (en) | 1981-01-23 | 1981-01-23 | |
| US06/330,175 US4429564A (en) | 1981-01-23 | 1981-12-14 | Vibration type density meter |
| GB8201395A GB2093998B (en) | 1981-01-23 | 1982-01-19 | Vibration-type density meter |
| CA000394732A CA1175544A (en) | 1981-01-23 | 1982-01-22 | Vibration-type density meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP889281U JPS6126912Y2 (en) | 1981-01-23 | 1981-01-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57122551U JPS57122551U (en) | 1982-07-30 |
| JPS6126912Y2 true JPS6126912Y2 (en) | 1986-08-12 |
Family
ID=29807034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP889281U Expired JPS6126912Y2 (en) | 1981-01-23 | 1981-01-23 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6126912Y2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0624761Y2 (en) * | 1986-07-17 | 1994-06-29 | 株式会社オーバル | Vibration type densitometer |
-
1981
- 1981-01-23 JP JP889281U patent/JPS6126912Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57122551U (en) | 1982-07-30 |
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