JPH07209265A - Sound wave reflection type gas concentration measuring apparatus - Google Patents
Sound wave reflection type gas concentration measuring apparatusInfo
- Publication number
- JPH07209265A JPH07209265A JP6002658A JP265894A JPH07209265A JP H07209265 A JPH07209265 A JP H07209265A JP 6002658 A JP6002658 A JP 6002658A JP 265894 A JP265894 A JP 265894A JP H07209265 A JPH07209265 A JP H07209265A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- temperature
- sound wave
- measured
- sound
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、音波の送受信の時間か
ら測定される音速に基づいて、ガス密度を測定する音波
反射式ガス濃度測定装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound wave reflection type gas concentration measuring device for measuring gas density based on the speed of sound measured from the time of transmission and reception of sound waves.
【０００２】[0002]
【従来の技術】音波伝達時間または音速を計測する際
に、温度による出力変動を補正する技術としては、例え
ば特開平２−１９８３５７号公報や特開平４−１５７３
５９号公報に記載された、温度特性を近似した計算式ま
たは温度特性を予め記憶したマップによるものが知られ
ている。2. Description of the Related Art As a technique for correcting an output fluctuation due to temperature when measuring a sound wave transmission time or a sound velocity, for example, Japanese Patent Laid-Open No. 2-198357 and Japanese Patent Laid-Open No. 4-1573 are known.
There is known a calculation formula that approximates the temperature characteristic or a map that stores the temperature characteristic in advance, which is described in Japanese Patent Laid-Open No. 59-59.
【０００３】また、例えば特開平１−１４５５２９号公
報に記載された、温度に対する音波伝達時間の変化が予
め知られている温度補正用送受信子を用いるものや、例
えば特公昭６１−２９４４９号公報に記載された、サー
ミスタの温度−抵抗特性を利用して行うもの等も知られ
ている。Further, for example, a device using a temperature-correcting transmitter-receiver whose change in sound wave transmission time with respect to temperature is known in advance, as disclosed in Japanese Patent Laid-Open No. 1-145529, and Japanese Patent Publication No. 61-29449, for example. There are also known ones that utilize the temperature-resistance characteristics of the thermistor described.
【０００４】[0004]
【発明が解決しようとする課題】温度特性を近似した計
算式または温度特性を予め記憶したマップによる技術
は、マイクロコンピュータによる演算を前提としてお
り、コストが高くなるという問題点を有する。また、温
度に対する音波伝達時間の変化が予め知られている温度
補正用送受信子を用いる技術は、別個の送受信子を設け
る必要があるため、コストが高くなり、装置が大型化す
るという問題点を有する。The technique based on a calculation formula approximating the temperature characteristic or a map in which the temperature characteristic is stored in advance is premised on the calculation by the microcomputer and has a problem that the cost becomes high. In addition, the technique of using a temperature-correcting transmitter / receiver whose change in sound wave transmission time with respect to temperature is known in advance requires a separate transmitter / receiver, resulting in high cost and a large device size. Have.
【０００５】従って、簡便かつ安価に温度による出力変
動を補正するには、サーミスタ等の感温素子を利用する
のが好ましい。Therefore, in order to simply and inexpensively correct the output fluctuation due to temperature, it is preferable to use a temperature sensitive element such as a thermistor.
【０００６】しかしながら、音波が伝搬するセンシング
エリア内に感温素子を配置する場合には、感温素子が音
波の伝搬を妨げたり、音波送受信子の受信波形に悪影響
を及ぼしたりすることがあった。この結果、音波伝達時
間または音速の測定誤差が増大するという問題点があっ
た。However, when the temperature sensitive element is arranged in the sensing area where the sound wave propagates, the temperature sensitive element may hinder the propagation of the sound wave or may adversely affect the reception waveform of the sound wave transceiver. . As a result, there is a problem that the measurement error of the sound wave transmission time or the sound velocity increases.
【０００７】このような問題点を避けるためには、感温
素子をセンシングエリアの隅に配置すればよいが、セン
シングエリアの隅においては被測定ガスの流れがよどん
でいることが多く、このような場合には、ガスの温度変
化に対する補正の応答性が悪くなるという問題点があっ
た。In order to avoid such a problem, the temperature sensitive element may be arranged at the corner of the sensing area, but the flow of the gas to be measured is often stagnant at the corner of the sensing area. In such a case, there is a problem that the response of the correction to the temperature change of the gas deteriorates.
【０００８】そこで、本発明の目的は、コスト上昇や装
置の大型化を伴うことがなく、精度が高く、しかも応答
性の良い音波反射式ガス濃度測定装置を提供することに
ある。Therefore, an object of the present invention is to provide a sound wave reflection type gas concentration measuring device which is highly accurate and has high responsiveness without increasing costs and increasing the size of the device.
【０００９】[0009]
【課題を解決するための手段】上記目的を達成するため
に、この出願に係る発明は、音波を反射する反射面と、
反射面に向けて音波を送信するとともに、反射した音波
を受信する音波送受信子と、音波送受信子及び反射面の
間の空間であるセンシングエリアと、センシングエリア
に被測定ガスを流入させるガス流入路と、ガス流入路内
に配置され、被測定ガスの温度を測定する感温素子とを
備え、音波の送受信の時間から測定される音速に基づい
てガスの密度を測定するとともに、感温素子の出力に基
づいて温度変動による誤差が補正されるものである。In order to achieve the above-mentioned object, the invention according to this application comprises a reflecting surface for reflecting sound waves,
A sound wave transceiver that transmits sound waves toward the reflecting surface and receives the reflected sound waves, a sensing area that is a space between the sound wave transceiver and the reflecting surface, and a gas inflow path that allows the measured gas to flow into the sensing area. And a temperature-sensitive element that is arranged in the gas inflow path and that measures the temperature of the gas to be measured, and that measures the density of the gas based on the speed of sound measured from the time of transmission and reception of sound waves. The error due to the temperature change is corrected based on the output.
【００１０】また、この出願に係る別の発明は、感温素
子が配置されるガス流入路の部分の口径が、他の部分の
口径よりも大きくされているものである。Further, another invention according to this application is such that the diameter of the gas inflow passage portion in which the temperature sensing element is arranged is larger than the diameters of the other portions.
【００１１】この出願に係るさらに別の発明は、音波を
反射する反射面と、反射面に向けて音波を送信するとと
もに、反射した音波を受信する音波送受信子と、音波送
受信子及び反射面の間の空間であるセンシングエリア
と、センシングエリアに被測定ガスを流入させるガス流
入路と、ガス流入路の中央線を延長した線がセンシング
エリアの内面と交わる位置に形成された凹部に配置さ
れ、被測定ガスの温度を測定する感温素子とを備え、音
波の送受信の時間から測定される音速に基づいてガスの
密度を測定するとともに、感温素子の出力に基づいて温
度変動による誤差が補正されるものである。Still another invention according to the present application is that a reflecting surface that reflects sound waves, a sound wave transceiver that transmits sound waves toward the reflecting surface and receives the reflected sound waves, and a sound wave transceiver and the reflecting surface. A sensing area that is a space between them, a gas inflow path for inflowing the gas to be measured into the sensing area, and a line formed by extending the center line of the gas inflow path is arranged in a recess formed at a position intersecting the inner surface of the sensing area, Equipped with a temperature sensitive element that measures the temperature of the gas to be measured, the density of the gas is measured based on the speed of sound measured from the time of transmission and reception of sound waves, and the error due to temperature fluctuation is corrected based on the output of the temperature sensitive element. It is what is done.
【００１２】[0012]
【作用】本発明においては、感温素子が配置される位置
を、音波送受信子から送信された音波が感温素子に直接
当たらない位置とし、さらに、ガス流入路を流れるガス
が感温素子に直接吹き付けられる位置とする。これによ
り、被測定ガスの温度変動に対する温度補正の応答性を
高めることができる。In the present invention, the position where the temperature sensitive element is arranged is set so that the sound wave transmitted from the sound wave transmitter / receiver does not directly hit the temperature sensitive element, and further, the gas flowing through the gas inflow path is applied to the temperature sensitive element. The position should be directly sprayed. As a result, it is possible to improve the responsiveness of the temperature correction to the temperature fluctuation of the gas to be measured.
【００１３】[0013]
【実施例】以下、添付図面に沿って本発明の実施例につ
いて説明する。なお、図面において同一又は相当部分に
は同一符号を用いるものとする。Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the same reference numerals are used for the same or corresponding parts in the drawings.
【００１４】図１は、この発明の一実施例を示す図であ
る。この音波反射式ガス濃度測定装置１は、エンジンの
キャニスタと吸入側とを結ぶキャニスタパージライン
（図示せず）の途中に設けられるものであり、パージガ
スの完全酸化に必要な空気量比を測定する装置である。
この音波反射式ガス濃度測定装置１は、超音波送受信子
２からセンシングエリア３内に送信され、反射面４で反
射されたパルス状音波の伝達時間によって音速を計測す
ることにより上記の空気量比のセンシングを行う。セン
シングエリア３内には、ガス流入路５から被測定ガスが
流入し、この被測定ガスはガス流出路６から流出してい
る。ガス流入路５及びガス流出路６は、超音波の伝達方
向、すなわちセンシングエリア３の軸方向にほぼ直交し
て配置されている。FIG. 1 is a diagram showing an embodiment of the present invention. The sound wave reflection type gas concentration measuring device 1 is provided in the middle of a canister purge line (not shown) connecting the canister and the intake side of the engine, and measures the air amount ratio required for complete oxidation of the purge gas. It is a device.
This sound wave reflection type gas concentration measuring device 1 measures the sound velocity by the transmission time of the pulsed sound wave transmitted from the ultrasonic wave transmitter / receiver 2 into the sensing area 3 and reflected by the reflection surface 4 to obtain the above air amount ratio. Sensing of. The gas to be measured flows into the sensing area 3 from the gas inflow path 5, and the gas to be measured flows out from the gas outflow path 6. The gas inflow path 5 and the gas outflow path 6 are arranged substantially orthogonal to the ultrasonic wave transmission direction, that is, the axial direction of the sensing area 3.
【００１５】このガス雰囲気中の超音波の伝達速度Ｃは
下記の式で表される。The ultrasonic wave transmission speed C in this gas atmosphere is expressed by the following equation.
【００１６】[0016]
【数１】 [Equation 1]
【００１７】ここに、Ｐは圧力、ρは密度、κは比熱
比、Ｒはガス定数、Ｔは絶対温度、Ｍはモル数である。Here, P is pressure, ρ is density, κ is specific heat ratio, R is gas constant, T is absolute temperature, and M is number of moles.
【００１８】超音波の伝達時間を測定することにより、
伝達速度Ｃを算出することができ、これにより雰囲気ガ
スの密度ρを求めることができるが、上式より明らかな
ように超音波の伝達速度Ｃは温度Ｔにより変動するた
め、温度補正が必要となる。このため、図１に示すよう
に、ガス流入路５内に感温素子７が配置されており、こ
の感温素子７により測定される温度によって温度補正を
行っている。感温素子７の位置は、超音波送受信子２か
ら送信された超音波が感温素子７に直接当たらない位置
となっている。このような位置に感温素子７を配置する
ことにより、感温素子７周辺のガスがよどむことがなく
なるため、感温素子７は常に新しく供給されるガスの温
度を測定することが可能となり、ガスの温度変動に対す
る温度補正の応答性を高めることができる。By measuring the transit time of ultrasonic waves,
The transmission velocity C can be calculated, and the density ρ of the atmospheric gas can be obtained from this, but as is clear from the above equation, the transmission velocity C of the ultrasonic wave changes with the temperature T, so that temperature correction is necessary. Become. Therefore, as shown in FIG. 1, the temperature sensing element 7 is arranged in the gas inflow path 5, and the temperature is corrected by the temperature measured by the temperature sensing element 7. The position of the temperature sensitive element 7 is a position where the ultrasonic wave transmitted from the ultrasonic wave transceiver 2 does not directly hit the temperature sensitive element 7. By arranging the temperature sensitive element 7 in such a position, the gas around the temperature sensitive element 7 is prevented from stagnation, so that the temperature sensitive element 7 can always measure the temperature of newly supplied gas, It is possible to improve the responsiveness of the temperature correction to the temperature change of the gas.
【００１９】図２は、この音波反射式ガス濃度測定装置
１の温度補正回路の一例を示したものである。音波反射
式ガス濃度測定装置１の出力信号は、音波伝達時間の定
数倍の周期を有する周期信号である。この周期信号の周
波数をｆとする。この周期信号を入力されてパルス発生
器８は、周期信号の周期ごとに一定時間Δｔのパルス信
号を出力する。このパルス信号のＨｉレベル電圧をＶ１
とする。この信号は感温素子７及び抵抗器９から構成さ
れる分圧回路に入力される。感温素子７はその抵抗値Ｒ
Ｔが温度Ｔによってリニアに変化し、温度Ｔが上昇する
と抵抗値ＲＴは大きくなる。また、抵抗器９の抵抗値を
Ｒとする。このとき、分圧回路中のａ点の電圧は、Ｒ／
（Ｒ＋ＲＴ）倍に分圧されたもの、すなわちＶ２＝Ｖ１
・Ｒ／（Ｒ＋ＲＴ）になる。さらに、この電圧が積分器
１０に入力される。積分器１０の出力は、ｆ・Δｔ・Ｖ２
になる。ここで、音波反射式ガス濃度測定装置１の使用
温度域（−２０〜１００℃程度）では、ｆは温度に対し
て概ね正の係数を持つということができ、温度上昇に伴
いｆはほぼリニアに増加する。また、感温素子７の温度
特性のために、Ｖ２は同じ温度域で温度に対して概ね負
の係数を持つということができ、温度上昇に伴いＶ２は
ほぼリニアに減少する。従って、ｆとＶ２とが相殺する
ように、抵抗器Ｒの抵抗値を選定すれば、積分器１０の
出力が温度によって変動することなく、目的のセンシン
グ量すなわち完全燃焼に必要な空気量比となるようにす
ることができる。FIG. 2 shows an example of the temperature correction circuit of the sound wave reflection type gas concentration measuring device 1. The output signal of the sound wave reflection type gas concentration measuring device 1 is a periodic signal having a cycle that is a constant multiple of the sound wave transmission time. The frequency of this periodic signal is f. Upon receiving this periodic signal, the pulse generator 8 outputs a pulse signal having a constant time Δt for each period of the periodic signal. The Hi level voltage of this pulse signal is V1
And This signal is input to the voltage dividing circuit composed of the temperature sensitive element 7 and the resistor 9. The temperature sensitive element 7 has a resistance value R
T changes linearly with the temperature T, and as the temperature T rises, the resistance value RT increases. Further, the resistance value of the resistor 9 is R. At this time, the voltage at the point a in the voltage dividing circuit is R /
One divided by (R + RT) times, that is, V2 = V1
・ It becomes R / (R + RT). Further, this voltage is input to the integrator 10. The output of the integrator 10 is f · Δt · V2
become. Here, in the operating temperature range of the acoustic wave reflection type gas concentration measuring device 1 (about -20 to 100 ° C), it can be said that f has a substantially positive coefficient with respect to temperature, and f increases substantially linearly with increasing temperature. Increase to. Further, due to the temperature characteristic of the temperature sensitive element 7, it can be said that V2 has a substantially negative coefficient with respect to temperature in the same temperature range, and V2 decreases almost linearly with increasing temperature. Therefore, if the resistance value of the resistor R is selected so that f and V2 cancel each other out, the output of the integrator 10 does not fluctuate with temperature, and the target sensing amount, that is, the air amount ratio required for complete combustion, is obtained. Can be.
【００２０】次に、ガス流入路５の口径が感温素子７に
比べて小さく、すなわちガス流入路５の流路断面積が感
温素子７に比べて小さく、ガス流入路５内に感温素子７
を入れることが物理的に不可能な場合には、図３に示す
ように、ガス流入路５がセンシングエリア３に至る部分
に口径拡大部１１を設け、その中に感温素子７を配置す
る。この場合、感温素子７の位置は、超音波送受信子２
から送信された超音波が感温素子７に直接当たらない位
置とし、さらに、ガス流入路５を流れるガスが感温素子
７に直接吹き付けられる位置とするのが好ましい。これ
により、被測定ガスの温度変動に対する温度補正の応答
性を高めることができる。Next, the diameter of the gas inflow path 5 is smaller than that of the temperature sensing element 7, that is, the cross-sectional area of the gas inflow path 5 is smaller than that of the temperature sensing element 7, and the temperature in the gas inflow path 5 is sensitive. Element 7
When it is physically impossible to insert the gas, as shown in FIG. 3, a caliber enlarged portion 11 is provided in a portion where the gas inflow passage 5 reaches the sensing area 3, and the temperature sensing element 7 is arranged therein. . In this case, the position of the temperature sensitive element 7 is set to the ultrasonic transmitter / receiver 2
It is preferable that the ultrasonic waves transmitted from the temperature sensing element 7 are not directly contacted with the ultrasonic waves and that the gas flowing through the gas inflow path 5 is directly blown to the temperature sensing element 7. As a result, it is possible to improve the responsiveness of the temperature correction to the temperature fluctuation of the gas to be measured.
【００２１】また、図４に示すように、センシングエリ
ア３に対してガス流入路５の対向側の位置、換言する
と、ガス流入路５の中央線を延長した線がセンシングエ
リア３の内面と交わる位置に凹部１２を形成し、この凹
部１２内に感温素子７を配置して温度補正を行ってもよ
い。Further, as shown in FIG. 4, a position on the opposite side of the gas inflow path 5 with respect to the sensing area 3, that is, a line extending from the center line of the gas inflow path 5 intersects with the inner surface of the sensing area 3. The temperature correction may be performed by forming the recess 12 at the position and disposing the temperature sensitive element 7 in the recess 12.
【００２２】このような配置とすることにより、ガス流
入路５からセンシングエリア３に流れ込むガスが感温素
子７に直接吹き当てられ、しかも超音波送受信子２から
送信された超音波が感温素子７に当たらないようにする
ことができる。さらに、感温素子７の存在による超音波
の乱れを防ぐことができ、超音波送受信子２の受信波形
に対する影響を小さくすることができる。With such an arrangement, the gas flowing from the gas inflow path 5 into the sensing area 3 is directly blown onto the temperature sensitive element 7, and the ultrasonic wave transmitted from the ultrasonic wave transmitter / receiver 2 is transmitted to the temperature sensitive element. You can avoid hitting 7. Further, it is possible to prevent the disturbance of ultrasonic waves due to the presence of the temperature sensitive element 7, and to reduce the influence on the reception waveform of the ultrasonic wave transmitter / receiver 2.
【００２３】なお、送信され受信される音波は超音波で
あるとしたが、超音波以外の音波であってもよい。Although the sound waves transmitted and received are ultrasonic waves, they may be sound waves other than ultrasonic waves.
【００２４】[0024]
【発明の効果】以上のように、本発明によれば、音波を
反射する反射面と、反射面に向けて音波を送信するとと
もに、反射した音波を受信する音波送受信子と、音波送
受信子及び反射面の間の空間であるセンシングエリア
と、センシングエリアに被測定ガスを流入させるガス流
入路と、ガス流入路内に配置され、被測定ガスの温度を
測定する感温素子とを備え、音波の送受信の時間から測
定される音速に基づいてガスの密度を測定するととも
に、感温素子の出力に基づいて温度変動による誤差が補
正されるので、コスト上昇や装置の大型化を伴うことが
なく、精度が高く、しかも応答性の良い音波反射式ガス
濃度測定装置を得ることができる。As described above, according to the present invention, a reflecting surface that reflects sound waves, a sound wave transceiver that transmits sound waves toward the reflecting surface and receives the reflected sound waves, a sound wave transceiver, and A sensing area, which is a space between the reflecting surfaces, a gas inflow path for allowing the gas to be measured to flow into the sensing area, and a temperature sensitive element that is disposed in the gas inflow path and measures the temperature of the gas to be measured, Since the gas density is measured based on the speed of sound measured from the transmission / reception time, and the error due to temperature fluctuation is corrected based on the output of the temperature sensing element, there is no increase in cost or increase in size of the device. Therefore, it is possible to obtain a sound wave reflection type gas concentration measuring device having high accuracy and good responsiveness.
【図１】この発明の一実施例を示す図である。FIG. 1 is a diagram showing an embodiment of the present invention.
【図２】この音波反射式ガス濃度測定装置１の温度補正
回路の一例を示した図である。FIG. 2 is a diagram showing an example of a temperature correction circuit of the sound wave reflection type gas concentration measuring device 1.
【図３】この発明の別の実施例を示す図である。FIG. 3 is a diagram showing another embodiment of the present invention.
【図４】この発明のさらに別の実施例を示す図である。FIG. 4 is a diagram showing still another embodiment of the present invention.
１…音波反射式ガス濃度測定装置、２…超音波送受信
子、３…センシングエリア、４…反射面、５…ガス流入
路、７…感温素子、１１…口径拡大部、１２…凹部。DESCRIPTION OF SYMBOLS 1 ... Sound wave reflection type gas concentration measuring device, 2 ... Ultrasonic wave transmitter / receiver, 3 ... Sensing area, 4 ... Reflection surface, 5 ... Gas inflow path, 7 ... Temperature sensing element, 11 ... Expanded diameter part, 12 ... Recessed part.
Claims (3)
音波を受信する音波送受信子と、 前記音波送受信子及び前記反射面の間の空間であるセン
シングエリアと、 前記センシングエリアに被測定ガスを流入させるガス流
入路と、 前記ガス流入路内に配置され、被測定ガスの温度を測定
する感温素子とを備え、 音波の送受信の時間から測定される音速に基づいて前記
ガスの密度を測定するとともに、前記感温素子の出力に
基づいて温度変動による誤差が補正される音波反射式ガ
ス濃度測定装置。1. A reflection surface for reflecting a sound wave, a sound wave transmitter / receiver for transmitting the sound wave toward the reflection surface and receiving the reflected sound wave, and a space between the sound wave transmitter / receiver and the reflection surface. A sensing area, a gas inflow path for allowing the gas to be measured to flow into the sensing area, and a temperature sensing element arranged in the gas inflow path for measuring the temperature of the gas to be measured, are measured from the time of transmission and reception of sound waves. The sound wave reflection type gas concentration measuring device, which measures the density of the gas based on the sound velocity, and corrects the error due to the temperature change based on the output of the temperature sensing element.
路の部分の口径が、他の部分の口径よりも大きくされて
いる請求項１記載の音波反射式ガス濃度測定装置。2. The acoustic wave reflection type gas concentration measuring device according to claim 1, wherein a diameter of a portion of the gas inflow path in which the temperature sensing element is arranged is larger than a diameter of another portion.
音波を受信する音波送受信子と、 前記音波送受信子及び前記反射面の間の空間であるセン
シングエリアと、 前記センシングエリアに被測定ガスを流入させるガス流
入路と、 前記ガス流入路の中央線を延長した線が前記センシング
エリアの内面と交わる位置に形成された凹部に配置さ
れ、被測定ガスの温度を測定する感温素子とを備え、 音波の送受信の時間から測定される音速に基づいて前記
ガスの密度を測定するとともに、前記感温素子の出力に
基づいて温度変動による誤差が補正される音波反射式ガ
ス濃度測定装置。3. A reflection surface that reflects sound waves, a sound wave transceiver that transmits sound waves toward the reflection surface and receives reflected sound waves, and a space between the sound wave transceiver and the reflection surface. The sensing area, a gas inflow path for letting the gas to be measured into the sensing area, and a line extending from the center line of the gas inflow path are arranged in a recess formed at a position intersecting with the inner surface of the sensing area, and the measured object is measured. A temperature sensing element for measuring the temperature of the gas is provided, and the density of the gas is measured based on the speed of sound measured from the time of transmission and reception of sound waves, and the error due to temperature fluctuation is corrected based on the output of the temperature sensing element. Acoustic wave reflection type gas concentration measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6002658A JPH07209265A (en) | 1994-01-14 | 1994-01-14 | Sound wave reflection type gas concentration measuring apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6002658A JPH07209265A (en) | 1994-01-14 | 1994-01-14 | Sound wave reflection type gas concentration measuring apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07209265A true JPH07209265A (en) | 1995-08-11 |
Family
ID=11535448
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6002658A Pending JPH07209265A (en) | 1994-01-14 | 1994-01-14 | Sound wave reflection type gas concentration measuring apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07209265A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1030176A2 (en) * | 1999-02-15 | 2000-08-23 | NGK Spark Plug Company Limited | Gas concentration sensor |
| WO2002057770A1 (en) * | 2001-01-22 | 2002-07-25 | Teijin Limited | Equipment and method for measuring concentration and flow rate of gas ultrasonically |
| JP2002214203A (en) * | 2001-01-22 | 2002-07-31 | Teijin Ltd | Ultrasonic reflection type method for measuring concentration of gas and apparatus therefor |
| JP2002214012A (en) * | 2001-01-22 | 2002-07-31 | Teijin Ltd | Ultrasonic gas concentration and flow rate measuring method and apparatus thereof |
| EP1020723A3 (en) * | 1999-01-11 | 2003-11-05 | NGK Spark Plug Company Limited | Gas concentration sensor |
| WO2008149868A1 (en) | 2007-05-31 | 2008-12-11 | Teijin Pharma Limited | Ultrasonic gas concentration measuring method and device using the same |
| FR2934409A1 (en) * | 2008-07-24 | 2010-01-29 | Commissariat Energie Atomique | Acoustic sensor for continuous and real time measurement of e.g. xenon, behavior in chamber i.e. nuclear fuel pencil, has transducer generating acoustic signal to vibrate plate and gas and detecting characteristic response signal |
| EP2366981A1 (en) | 2003-04-21 | 2011-09-21 | Teijin Pharma Limited | Oxygen concentration system for generating oxygen-enriched gas |
-
1994
- 1994-01-14 JP JP6002658A patent/JPH07209265A/en active Pending
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1020723A3 (en) * | 1999-01-11 | 2003-11-05 | NGK Spark Plug Company Limited | Gas concentration sensor |
| EP1030176A2 (en) * | 1999-02-15 | 2000-08-23 | NGK Spark Plug Company Limited | Gas concentration sensor |
| EP1030176A3 (en) * | 1999-02-15 | 2003-11-05 | NGK Spark Plug Company Limited | Gas concentration sensor |
| US6912907B2 (en) | 2001-01-22 | 2005-07-05 | Teijin Limited | Ultrasonic apparatus and method for measuring the concentration and flow rate of gas |
| JP2002214012A (en) * | 2001-01-22 | 2002-07-31 | Teijin Ltd | Ultrasonic gas concentration and flow rate measuring method and apparatus thereof |
| JP2002214203A (en) * | 2001-01-22 | 2002-07-31 | Teijin Ltd | Ultrasonic reflection type method for measuring concentration of gas and apparatus therefor |
| WO2002057770A1 (en) * | 2001-01-22 | 2002-07-25 | Teijin Limited | Equipment and method for measuring concentration and flow rate of gas ultrasonically |
| KR100943874B1 (en) * | 2001-01-22 | 2010-02-24 | 데이진 가부시키가이샤 | Equipment and method for measuring concentration and flow rate of gas ultrasonically |
| JP4536939B2 (en) * | 2001-01-22 | 2010-09-01 | 帝人株式会社 | Ultrasonic reflection type gas concentration measuring method and apparatus |
| EP2366981A1 (en) | 2003-04-21 | 2011-09-21 | Teijin Pharma Limited | Oxygen concentration system for generating oxygen-enriched gas |
| WO2008149868A1 (en) | 2007-05-31 | 2008-12-11 | Teijin Pharma Limited | Ultrasonic gas concentration measuring method and device using the same |
| US8746037B2 (en) | 2007-05-31 | 2014-06-10 | Teijin Pharma Limited | Ultrasonic apparatus and method for measuring the concentration of gas |
| FR2934409A1 (en) * | 2008-07-24 | 2010-01-29 | Commissariat Energie Atomique | Acoustic sensor for continuous and real time measurement of e.g. xenon, behavior in chamber i.e. nuclear fuel pencil, has transducer generating acoustic signal to vibrate plate and gas and detecting characteristic response signal |
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