JP3367827B2 - Micro flowmeter for vacuum - Google Patents
Micro flowmeter for vacuumInfo
- Publication number
- JP3367827B2 JP3367827B2 JP17654696A JP17654696A JP3367827B2 JP 3367827 B2 JP3367827 B2 JP 3367827B2 JP 17654696 A JP17654696 A JP 17654696A JP 17654696 A JP17654696 A JP 17654696A JP 3367827 B2 JP3367827 B2 JP 3367827B2
- Authority
- JP
- Japan
- Prior art keywords
- resistance heating
- heating element
- downstream
- upstream
- flow rate
- 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 - Fee Related
Links
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は、大気圧以下の真空
に近い圧力下において流れる例えばガス等の流体の流量
を計測する真空用微小流量計に関する。
【０００２】
【従来の技術】大気圧以下の真空に近い圧力下において
流れる気体の流量を計測する従来の真空用微小流量計
は、図６に示すように構成されている。図６に示すよう
に真空用微小流量計１は、センサ部２とバイパス部３か
らなり、計測する流路４に設けられる。センサ部２は、
毛細管５を使用し、この毛細管５に二つのヒータ（抵抗
発熱体）６，７を巻回している。このヒータ６，７は、
ブリッジ回路（図示せず）に接続され、このブリッジ回
路により、ヒータ６，７の抵抗値が測定される。また、
バイパス部３は、センサ部２と同等の毛細管を使用して
層流素子バイパスを構成している。
【０００３】上記センサ部２は、ヒータ６，７により加
熱されて温度が上昇するが、その温度分布は図６に示す
ようになる。すなわち、気体が流れていない場合の温度
分布は、毛細管５の中央部が最も高く、両端部に近い程
低くなっているが、気体が流れると、温度の最高部が毛
細管５の末端方向に移動する。
【０００４】上記センサ部２に流れる気体の流量は最大
で１０ｍｌ／ｍｉｎ程度であるため、殆どの気体はバイ
パス部３に流れる。センサ部２の流量をＱｓ、バイパス
部３の流量をＱｂとすると、総流量Ｑは「Ｑ＝Ｑｓ＋Ｑ
ｂ」であり、分流比ｋは「Ｑｂ／Ｑｓ＝ｋ」で表され
る。
【０００５】そして、上記センサ部２における抵抗発熱
体であるヒータ６，７の温度差を、その電気抵抗差より
求め、質量流量を測定する。ここで、質量流量は、通常
ｓｃｃｍ（ｓｔａｎｄａｒｄ ｃｃ／ｍｉｎ．）と呼ば
れる大気圧１５℃における気体の体積の単位時間当りの
流量で表される。上記ｓｃｃｍ以外にｓｌｍ（ｓｔａｎ
ｄａｒｄ ｌ／ｍｉｎ．）も用いられる。
【０００６】
【発明が解決しようとする課題】流路４内が真空に近い
環境下では、ヒータ（抵抗発熱体）６，７から流路４中
に流れる気体への伝熱が悪くなるため、相対的に配管
（流路４）を熱伝導で伝わる伝熱量が大きくなる。この
ためセンサ部２の上流と下流に温度差をつけるために流
量を大きくしたり、あるいはヒータ６，７を設置する毛
細管５を細くする必要がある。このため圧力損失が１Ｔ
ｏｒｒ以上となって許容範囲を越えてしまい、計測器の
後流側に必要流量が流れなくなるという問題がある。
【０００７】本発明は上記の課題を解決するためになさ
れたもので、真空環境下でも圧力損失が殆どなく、質量
流量の測定が可能な真空用微小流量計を提供することを
目的とする。
【０００８】
【課題を解決するための手段】本発明に係る真空用微小
流量計は、低熱伝導のベースフィルム上に平板状の上流
側抵抗発熱体及び下流側抵抗発熱体を設けてセンサ部を
構成し、前記センサ部の上流側抵抗発熱体及び下流側抵
抗発熱体にそれぞれ低熱伝導支持線を接続して該センサ
部を真空に近い圧力下の流体が流れる流路内に支持する
と共に、前記低熱伝導支持線を前記流路から外部に導出
して計測用ブリッジ回路に接続し、前記ブリッジ回路に
より前記上流側抵抗発熱体及び下流側抵抗発熱体の抵抗
値を測定し、該抵抗値に基づいて前記上流側抵抗発熱体
及び下流側抵抗発熱体の温度分布を求めて前記流体の流
量を計測することを特徴とする。
【０００９】上記のように上流側抵抗発熱体及び下流側
抵抗発熱体を低熱伝導率のベースフィルムに設置し、低
熱伝導の支持線で保持することにより、抵抗発熱体の発
熱は殆ど流体に伝えられる。この結果、真空環境下で気
体と抵抗発熱体との熱伝達率が悪い状態においても、上
流側抵抗発熱体と下流側抵抗発熱体との温度差が顕著に
なり、質量流量を確実に測定することができる。
【００１０】
【発明の実施の形態】以下、図面を参照して本発明の一
実施形態を説明する。図１は本発明の一実施形態に係る
真空用微小流量計の正面図、図２は同平面図である。図
１及び図２において、１１は流路で、この流路１１の途
中にセンサ部１２が水平に設けられる。このセンサ部１
２は、図３に詳細を示すように低熱伝導のベースフィル
ム１３上に平板状に形成された上流側抵抗発熱体１４及
び下流側抵抗発熱体１５を設けたものである。上記セン
サ部１２は、図１に示すように低熱伝導の保持用フィル
ム１８により保持され、流路１１内に平行に設けられ
る。上記抵抗発熱体１４，１５は、同じ特性を有するも
ので、それぞれ低熱伝導の支持線１６，１７により流路
１１に支持される。上記支持線１６，１７としては、熱
伝導の非常に小さい部材、例えば直径１０μｍ程度の銅
線が用いられる。また、上記抵抗発熱体１４，１５は、
上記支持線１６，１７を介してブリッジ回路１９に接続
され、このブリッジ回路１９により抵抗発熱体１４，１
５の抵抗値が測定される。そして、この抵抗発熱体１
４，１５の抵抗値に基づいて上流側抵抗発熱体１４と下
流側抵抗発熱体１５との温度差が演算回路（図示せず）
により算出され、更に、この温度差から流体の流量が求
められる。
【００１１】次に上記実施形態の動作を説明する。セン
サ部１２の抵抗発熱体１４，１５には、同じ電流量が供
給され、その発熱により流路１１内を流れる流体、すな
わち気体が加熱される。この場合は、流路１１内を流れ
る気体は、まず、上流側抵抗発熱体１４に加熱されて下
流側抵抗発熱体１５に達する。従って、下流側抵抗発熱
体１５の温度は、上流側抵抗発熱体１４の温度より高く
なる。ベースフィルム１３、保持用フィルム１８及び支
持線１６，１７は、熱伝導が非常に小さいので、流路１
１内を流れる気体が流量が微小であっても、上流側抵抗
発熱体１４と下流側抵抗発熱体１５との温度差が顕著に
現れる。
【００１２】上記抵抗発熱体１４，１５の抵抗値がブリ
ッジ回路１９により計測され、その抵抗値に基づいて抵
抗発熱体１４，１５の温度差が算出される。更に、この
温度差から流体の質量流量を求めることができる。
【００１３】図４は、ブリッジ回路１９で測定された電
圧（センサ出力）と真空槽の圧力上昇により求めた流量
との関係を示したものである。この図から明らかなよう
に真空環境下でも、微小流量を測定することができるも
のである。また、このときの圧力損失は０．１Ｔｏｒｒ
以下で、許容範囲内に収まっている。
【００１４】次に上流側抵抗発熱体１４と下流側抵抗発
熱体１５の温度差から流体の質量流量を求める場合の原
理について説明する。図５は、センサ部１２における温
度分布状態を示したもので、実線ａは気体流量が０、破
線ｂは気体流量が微小、破線ｃは気体流量が小、破線ｄ
は気体流量が大の場合の温度分布特性である。
【００１５】今、上流側抵抗発熱体１４の温度をＴ1 、
下流側抵抗発熱体１５の温度をＴ2とすると、抵抗発熱
体１４から気体への伝熱量Ｑg1、抵抗発熱体１５から気
体への伝熱量Ｑg2、下流側抵抗発熱体１５の位置での気
体温度Ｔg2等は、次のような関係がある。
【００１６】
Ｑg1＝αＡ（Ｔ1 −Ｔg1） …（１）
Ｑg2＝αＡ（Ｔ2 −Ｔg2） …（２）
Ｔg2＝｛Ｑg1／（Ｃp Ｗg ）｝＋Ｔg1 …（３）
但し、Ｑg1：抵抗発熱体１４から気体への伝熱量（Ｗ）
Ｑg2：抵抗発熱体１５から気体への伝熱量（Ｗ）
Ｔg1：上流側抵抗発熱体１４の位置での気体温度（℃）
Ｔg2：下流側抵抗発熱体１５の位置での気体温度（℃）
α ：気体への熱伝達率（Ｗ／ｍ2 ℃）
Ａ ：伝熱面積（ｍ2 ）
Ｃp ：気体比熱（ｊ／ｋｇ℃）
Ｗg ：気体流量（ｋｇ／ｓ）
そして、上記（１）式〜（３）式から上流側抵抗発熱体
１４の位置での気体温度Ｔg1及び下流側抵抗発熱体１５
の位置での気体温度Ｔg2を消去すると、
ｆ＝（Ｑg1，Ｑg2，α，Ｔ1 ，Ｔ2 ）＝０
の関係が得られる。
【００１７】ここで、Ｑg1，Ｑg2，αは、気体流量Ｗg
の関数であるので、予め検定することで、気体流量Ｗg
と抵抗発熱体１４，１５の温度Ｔ1 ，Ｔ2 の関係を求め
ることができる。
【００１８】
【発明の効果】以上詳記したように本発明によれば、抵
抗発熱体１４，１５を低熱伝導率のベースフィルム１３
に設置し、低熱伝導の支持線１６，１７で保持すること
により、抵抗発熱体１４，１５の発熱は殆ど流体に伝え
られる。この結果、真空環境下で気体と抵抗発熱体１
４，１５との熱伝達率が悪い状態においても、上流側抵
抗発熱体１４と下流側抵抗発熱体１５との温度差が顕著
になり、質量流量を確実に測定することができる。すな
わち、従来技術のように流路を細くする必要がないの
で、真空環境下でも圧力損失が殆どなく、質量流量を確
実に測定することができる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro flowmeter for vacuum which measures a flow rate of a fluid such as a gas flowing under a pressure close to a vacuum below the atmospheric pressure. 2. Description of the Related Art A conventional vacuum micro flowmeter for measuring a flow rate of a gas flowing under a pressure close to a vacuum below the atmospheric pressure is configured as shown in FIG. As shown in FIG. 6, the minute flow meter for vacuum 1 includes a sensor unit 2 and a bypass unit 3 and is provided in a flow path 4 to be measured. The sensor unit 2
A capillary 5 is used, and two heaters (resistance heating elements) 6 and 7 are wound around the capillary 5. These heaters 6 and 7
It is connected to a bridge circuit (not shown), and the resistance value of the heaters 6 and 7 is measured by the bridge circuit. Also,
The bypass unit 3 forms a laminar flow element bypass using a capillary tube equivalent to the sensor unit 2. The temperature of the sensor section 2 is increased by being heated by the heaters 6 and 7, and its temperature distribution is as shown in FIG. In other words, the temperature distribution when no gas is flowing is highest at the center of the capillary 5 and lower nearer to both ends, but when gas flows, the highest temperature moves toward the end of the capillary 5. I do. Since the flow rate of the gas flowing through the sensor section 2 is about 10 ml / min at the maximum, most of the gas flows into the bypass section 3. Assuming that the flow rate of the sensor section 2 is Qs and the flow rate of the bypass section 3 is Qb, the total flow rate Q is “Q = Qs + Q”.
b ", and the split ratio k is represented by" Qb / Qs = k ". Then, the temperature difference between the heaters 6 and 7, which are resistance heating elements in the sensor section 2, is determined from the difference in electric resistance, and the mass flow rate is measured. Here, the mass flow rate is represented by a flow rate per unit time of a gas volume at an atmospheric pressure of 15 ° C., usually called sccm (standard cc / min.). Slm (stan
dard l / min. ) Is also used. In an environment where the inside of the flow path 4 is close to a vacuum, heat transfer from the heaters (resistance heating elements) 6 and 7 to the gas flowing in the flow path 4 becomes poor. The amount of heat transferred through the pipe (flow path 4) by heat conduction is relatively large. For this reason, it is necessary to increase the flow rate or to make the capillary 5 in which the heaters 6 and 7 are installed thin in order to provide a temperature difference between the upstream and downstream of the sensor section 2. Therefore, pressure loss is 1T
There is a problem that the required flow rate does not flow to the downstream side of the measuring instrument due to exceeding orr and exceeding the allowable range. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a micro flowmeter for vacuum capable of measuring a mass flow rate with almost no pressure loss even in a vacuum environment. A minute flow meter for vacuum according to the present invention is provided with a plate-like upstream resistance heating element and a downstream resistance heating element on a base film having low thermal conductivity, and a sensor section is provided.
And an upstream resistance heating element and a downstream resistance of the sensor section.
The low heat conduction supporting wires are connected to the anti-heating elements, respectively.
Part is supported in the flow path where fluid under pressure close to vacuum flows
At the same time, the low thermal conductive support wire is led out of the flow path to the outside.
And connect it to the bridge circuit for measurement.
The resistance of the upstream resistance heating element and the downstream resistance heating element
Measured value, characterized in that seeking temperature distribution of the upstream-side resistance heating element and the downstream resistive heating element based on the resistance value for measuring the flow rate of the fluid. As described above, the upstream resistance heating element and the downstream resistance heating element are installed on the base film having a low thermal conductivity, and are held by the supporting lines having a low thermal conductivity. Can be As a result, even in a state where the heat transfer coefficient between the gas and the resistance heating element is poor in a vacuum environment, the temperature difference between the upstream resistance heating element and the downstream resistance heating element becomes remarkable, and the mass flow rate is reliably measured. be able to. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a micro flowmeter for vacuum according to an embodiment of the present invention, and FIG. 2 is a plan view of the same. 1 and 2, reference numeral 11 denotes a flow path, and a sensor unit 12 is provided horizontally in the middle of the flow path 11. This sensor unit 1
Reference numeral 2 denotes an arrangement in which an upstream resistance heating element 14 and a downstream resistance heating element 15 which are formed in a plate shape on a low heat conduction base film 13 as shown in detail in FIG. The sensor section 12 is held by a holding film 18 having low thermal conductivity as shown in FIG. The resistance heating elements 14 and 15 have the same characteristics and are supported by the flow path 11 by supporting wires 16 and 17 having low heat conduction, respectively. As the support wires 16 and 17, a member having extremely low heat conductivity, for example, a copper wire having a diameter of about 10 μm is used. The resistance heating elements 14 and 15 are
The bridge circuit 19 is connected to the bridge circuit 19 via the support wires 16 and 17, and the bridge circuit 19 allows the resistance heating elements 14 and 1 to be connected.
A resistance value of 5 is measured. And this resistance heating element 1
An arithmetic circuit (not shown) calculates a temperature difference between the upstream resistance heating element 14 and the downstream resistance heating element 15 based on the resistance values 4 and 15.
, And the flow rate of the fluid is obtained from the temperature difference. Next, the operation of the above embodiment will be described. The same amount of current is supplied to the resistance heating elements 14 and 15 of the sensor unit 12, and the fluid that flows in the flow path 11, that is, the gas, is heated by the generated heat. In this case, the gas flowing in the flow path 11 is first heated by the upstream resistance heating element 14 and reaches the downstream resistance heating element 15. Therefore, the temperature of the downstream resistance heating element 15 becomes higher than the temperature of the upstream resistance heating element 14. Since the base film 13, the holding film 18, and the support wires 16, 17 have very low heat conduction, the flow path 1
Even if the flow rate of the gas flowing through the inside 1 is very small, the temperature difference between the upstream resistance heating element 14 and the downstream resistance heating element 15 appears remarkably. The resistance values of the resistance heating elements 14 and 15 are measured by the bridge circuit 19, and the temperature difference between the resistance heating elements 14 and 15 is calculated based on the resistance values. Further, the mass flow rate of the fluid can be obtained from the temperature difference. FIG. 4 shows the relationship between the voltage (sensor output) measured by the bridge circuit 19 and the flow rate obtained by increasing the pressure in the vacuum chamber. As is clear from this figure, a minute flow rate can be measured even in a vacuum environment. The pressure loss at this time is 0.1 Torr
Below, it is within the allowable range. Next, the principle of obtaining the mass flow rate of the fluid from the temperature difference between the upstream resistance heating element 14 and the downstream resistance heating element 15 will be described. FIG. 5 shows a temperature distribution state in the sensor unit 12, wherein a solid line a has a gas flow rate of 0, a dashed line b has a small gas flow rate, a dashed line c has a small gas flow rate, and a dashed line d.
Is a temperature distribution characteristic when the gas flow rate is large. Now, let the temperature of the upstream resistance heating element 14 be T1,
Assuming that the temperature of the downstream resistance heating element 15 is T2, the heat transfer quantity Qg1 from the resistance heating element 14 to the gas, the heat transfer quantity Qg2 from the resistance heating element 15 to the gas, and the gas temperature Tg2 at the position of the downstream resistance heating element 15 Etc. have the following relationship. Qg1 = αA (T1−Tg1) (1) Qg2 = αA (T2−Tg2) (2) Tg2 = {Qg1 / (CpWg)} + Tg1 (3) where Qg1: resistance heating element 14 Qg2: Heat transfer amount from resistance heating element 15 to gas (W) Tg1: Gas temperature (° C.) at position of upstream resistance heating element 14 Tg2: Downstream resistance heating element 15 Gas temperature at position (° C.) α: Heat transfer coefficient to gas (W / m 2 ° C.) A: Heat transfer area (m 2 ) Cp: Gas specific heat (j / kg ° C.) Wg: Gas flow rate (kg / s) From the above equations (1) to (3), the gas temperature Tg1 at the position of the upstream resistance heating element 14 and the downstream resistance heating element 15
Eliminating the gas temperature Tg2 at the position (1), the following relationship is obtained: f = (Qg1, Qg2, α, T1, T2) = 0. Here, Qg1, Qg2, α are gas flow rates Wg
Therefore, by performing a test in advance, the gas flow rate Wg
And the temperatures T1 and T2 of the resistance heating elements 14 and 15 can be obtained. As described above in detail, according to the present invention, the resistance heating elements 14 and 15 are connected to the base film 13 having a low thermal conductivity.
The heat generated by the resistance heating elements 14 and 15 is almost transmitted to the fluid. As a result, the gas and the resistance heating element 1 in a vacuum environment
Even when the heat transfer coefficient between the upstream resistance heating element 14 and the downstream resistance heating element 15 is low, the temperature difference between the upstream resistance heating element 14 and the downstream resistance heating element 15 becomes remarkable, and the mass flow rate can be reliably measured. That is, since it is not necessary to make the flow path thinner as in the prior art, there is almost no pressure loss even in a vacuum environment, and the mass flow rate can be reliably measured.
【図面の簡単な説明】
【図１】本発明の一実施形態に係る真空用微小流量計の
正面図。
【図２】同実施形態における真空用微小流量計の平面
図。
【図３】同実施形態におけるセンサ部の詳細を示す図。
【図４】同実施形態におけるセンサ出力と真空槽の圧力
上昇により求めた流量との関係を示す図。
【図５】同実施形態におけるセンサ部の温度分布状態を
示す図。
【図６】従来の真空用微小流量計の構成及びセンサ部の
温度分布を示す図。
【符号の説明】
１１ 流路
１２ センサ部
１３ ベースフィルム
１４ 上流側抵抗発熱体
１５ 下流側抵抗発熱体
１６，１７ 支持線
１８ 保持用フィルム
１９ ブリッジ回路BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a micro flowmeter for vacuum according to an embodiment of the present invention. FIG. 2 is a plan view of the minute flow meter for vacuum in the embodiment. FIG. 3 is a diagram showing details of a sensor unit in the embodiment. FIG. 4 is a view showing a relationship between a sensor output and a flow rate obtained by a rise in the pressure of a vacuum chamber in the embodiment. FIG. 5 is a diagram showing a temperature distribution state of a sensor unit in the embodiment. FIG. 6 is a diagram showing a configuration of a conventional micro flowmeter for vacuum and a temperature distribution of a sensor unit. [Description of Signs] 11 Flow path 12 Sensor unit 13 Base film 14 Upstream resistance heating element 15 Downstream resistance heating element 16, 17 Support wire 18 Holding film 19 Bridge circuit
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平８−105777（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01F 1/00 - 9/02 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-105777 (JP, A) (58) Field surveyed (Int. Cl. 7 , DB name) G01F 1/00-9/02
Claims (1)
上流側抵抗発熱体及び下流側抵抗発熱体を設けてセンサ
部を構成し、前記センサ部の上流側抵抗発熱体及び下流
側抵抗発熱体にそれぞれ低熱伝導支持線を接続して該セ
ンサ部を真空に近い圧力下の流体が流れる流路内に支持
すると共に、前記低熱伝導支持線を前記流路から外部に
導出して計測用ブリッジ回路に接続し、前記ブリッジ回
路により前記上流側抵抗発熱体及び下流側抵抗発熱体の
抵抗値を測定し、該抵抗値に基づいて前記上流側抵抗発
熱体及び下流側抵抗発熱体の温度分布を求めて前記流体
の流量を計測することを特徴とする真空用微小流量計。(57) [Claim 1] A sensor in which a flat upstream resistance heating element and a downstream resistance heating element are provided on a base film having low thermal conductivity.
A resistance heating element upstream and downstream of the sensor section.
Connect the low thermal conductive support wires to each side resistance heating element and
The sensor part is supported in the flow path where fluid under a pressure close to vacuum flows.
And at the same time, the low thermal conductive support wire is
Derived and connected to a bridge circuit for measurement.
The upstream resistance heating element and the downstream resistance heating element
A minute flowmeter for vacuum, comprising: measuring a resistance value; obtaining a temperature distribution of the upstream resistance heating element and the downstream resistance heating element based on the resistance value ; and measuring a flow rate of the fluid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17654696A JP3367827B2 (en) | 1996-07-05 | 1996-07-05 | Micro flowmeter for vacuum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17654696A JP3367827B2 (en) | 1996-07-05 | 1996-07-05 | Micro flowmeter for vacuum |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1019621A JPH1019621A (en) | 1998-01-23 |
| JP3367827B2 true JP3367827B2 (en) | 2003-01-20 |
Family
ID=16015483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17654696A Expired - Fee Related JP3367827B2 (en) | 1996-07-05 | 1996-07-05 | Micro flowmeter for vacuum |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3367827B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6247499B2 (en) * | 2013-10-29 | 2017-12-13 | 株式会社フジキン | Gas flow meter |
| JP6939191B2 (en) * | 2017-07-26 | 2021-09-22 | 東京電力ホールディングス株式会社 | Flow meter and flow measurement method |
-
1996
- 1996-07-05 JP JP17654696A patent/JP3367827B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1019621A (en) | 1998-01-23 |
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| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20021008 |
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| LAPS | Cancellation because of no payment of annual fees |