JPS61209347A - Hot wire type semiconductive gas alarm - Google Patents
Hot wire type semiconductive gas alarmInfo
- Publication number
- JPS61209347A JPS61209347A JP4840785A JP4840785A JPS61209347A JP S61209347 A JPS61209347 A JP S61209347A JP 4840785 A JP4840785 A JP 4840785A JP 4840785 A JP4840785 A JP 4840785A JP S61209347 A JPS61209347 A JP S61209347A
- Authority
- JP
- Japan
- Prior art keywords
- wire type
- hot wire
- power
- gas
- type semiconductive
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
- G01N27/122—Circuits particularly adapted therefor, e.g. linearising circuits
Abstract
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、熱線型半導体素子に間欠通電し。[Detailed description of the invention] [Industrial application field] This invention applies intermittent current to a hot wire type semiconductor element.
通電直後の過渡現象を利用しエガスの検出を行うガス警
報器に関するものである。This invention relates to a gas alarm that detects gas by utilizing a transient phenomenon immediately after energization.
従来からガス検知のための種々のガス検知素子が提案さ
れている。このう、ち、よく使用されるものに接触燃焼
式と半導体式とがある。前者は白金コイルに触媒を焼結
したもので、可燃性ガスを含んだ空気が触媒活性な表面
（約３００’ＣＫｆｆｌｒ、：れている）に接触すると
、漏発下限界以下の濃度であっても可燃性ガスと酸素が
反応し、反応熱が発生するため、白金コイルの温度が上
昇し、その抵抗値が増大するので、この抵抗値変化をブ
リッジ回路等で検出しガスを検知するものである。Conventionally, various gas detection elements for gas detection have been proposed. Among these, the catalytic combustion type and the semiconductor type are commonly used. The former has a catalyst sintered onto a platinum coil, and when air containing flammable gas comes into contact with the catalytically active surface (approximately 300'CKfflr), the concentration is below the leakage limit. The combustible gas and oxygen react and generate heat of reaction, which raises the temperature of the platinum coil and increases its resistance value. This change in resistance value is detected by a bridge circuit, etc. to detect the gas. be.
この接触燃焼式のガス検知素子は、感度特性に直線性を
有するが、長期安定性の点では半導体式のガス検知素子
に劣っている。Although this catalytic combustion type gas detection element has linear sensitivity characteristics, it is inferior to semiconductor type gas detection elements in terms of long-term stability.
一方、半導体式のガス検知素子は金属酸化物半導体例え
ば５ｎＯｔ ＋ Ｚｎ Ｏなとを一対の電極間に亘つ
又焼結したもので、一方の電極をコイル状に形成してヒ
ータ兼用電極として通常用いる。On the other hand, semiconductor-type gas sensing elements are made by sintering a metal oxide semiconductor such as 5nOt + ZnO between a pair of electrodes, and one electrode is formed into a coil shape and is usually used as a heater electrode. use
セし工、ヒータ兼用電極により３００℃〜４００℃の温
度に保っておき、ガス吸着により半導体装置導度が増大
し、両電極間の抵抗値が低くなるのを検出することでガ
ス検知を行う。The temperature is maintained at 300°C to 400°C using an electrode that also serves as a heater and a heater, and the conductivity of the semiconductor device increases due to gas adsorption, and gas detection is performed by detecting that the resistance value between both electrodes decreases. .
この半導体式のガス検知素子は、接触燃焼式に比べ長寿
命で長期安定性に優れており、しかも被毒に対し接触燃
焼式より優れているが、消費電力が大営いため電源トラ
ンスなど電源部の容量が大きくなり、コストが高くなる
。This semiconductor type gas detection element has a longer lifespan and superior long-term stability than the catalytic combustion type, and is also better against poisoning than the catalytic combustion type, but it consumes a lot of power, so the power supply parts such as the power transformer etc. The capacity becomes larger and the cost becomes higher.
また後述する熱線型半導体素子忙比べ、電圧依存度が大
業いため性能を上げようとすると定電圧回路が必要にな
るが、消費電力が大きいため定電圧回路のコストが高く
なる。In addition, compared to the hot wire type semiconductor device described later, the voltage dependence is much greater, so if you want to improve the performance, a constant voltage circuit is required, but the cost of the constant voltage circuit is high because of the large power consumption.
またガスセンサの熱容量が大きいため安定するまでに時
間がかかり、そのため調整に長時間′Ｉｋ：要し、不安
定になり生産性が悪く、さらに温湿度依存度が大きいた
め、温度補償回路が必要となるなどの問題点があった。In addition, since the gas sensor has a large heat capacity, it takes a long time to stabilize, so it takes a long time to adjust, resulting in instability and poor productivity.Furthermore, it is highly dependent on temperature and humidity, so a temperature compensation circuit is required. There were some problems, such as:
一方、使用するガス検知素子の種類とは別Ｋ。On the other hand, the type of gas detection element used is different.
ガス警報器の電源として、商用電源または電池が用いら
れている。商用電源の場合忙は電池のように消耗による
交換を必要としないが、コードが邪魔になること、トラ
ンスを用い工電圧Ｙ遍降しなければならないこと等々の
問題があり、また電池を用いる場合は、携帯用に便利で
あるが、消耗のために新しい電池とＷ４繁に交換しなけ
ればならず、これを怠るとガス検知が行われず大事故に
なる等の問題点があっに０
そこで、電池Ｖｔａとするガス警報器において、電池の
寿命を延ばすためＫ、電源の供給ン間欠的に行うものが
提案されている。例えば、実開昭５６−５５９９８号公
報、実開昭５７−５７９４号公報等がその一例である。Commercial power or batteries are used as a power source for gas alarms. When using a commercial power source, unlike batteries, there is no need to replace it due to wear and tear, but there are problems such as the cord getting in the way and the need to use a transformer to change the voltage across the line, and when using batteries. Although it is convenient to carry, the battery has to be replaced frequently with a new one due to consumption, and if this is neglected, there are problems such as gas detection not being performed and a serious accident. In a gas alarm using a battery Vta, it has been proposed that power is supplied intermittently to extend the life of the battery. For example, Japanese Utility Model Application Publication No. 56-55998 and Japanese Utility Model Application Publication No. 57-5794 are examples.
上記実開昭５６−５５９９８号公報では接触燃焼式素子
の触媒劣化ｌ防ぐために二重パルス電源部している。ま
た実開昭５７−５７９４号公報は間欠的に電源を供給し
ていても、基本的には常時通電させているのと同じく接
触燃焼式素子の温度を一定に保とうとするものである。In the above-mentioned Japanese Utility Model Application Publication No. 56-55998, a double pulse power source is used to prevent catalyst deterioration of the catalytic combustion type element. Further, Japanese Utility Model Publication No. 57-5794 attempts to maintain the temperature of the catalytic combustion type element at a constant level even if power is supplied intermittently, as in the case where electricity is constantly supplied.
何れも省電力が目的であり、長時間使用することＫより
触媒劣化が起るものであり、常時センサを加熱する従来
技術の域を超えるものでなかった。In both cases, the purpose is to save power, and catalyst deterioration occurs when used for a long time, so they are no better than conventional techniques that constantly heat the sensor.
この発明各文、上記問題点を解決するため忙なされたも
ので、ガス検知素子への供給する電力を節減しながら触
媒の劣化が生じｋくい熱１ｍＷ半導体式ガス書報器を提
供することを目的とする。The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a 1 mW semiconductor type gas recorder that reduces the amount of power supplied to the gas detection element and reduces the amount of heat that causes deterioration of the catalyst. purpose.
この発ｄＡＶｃ係るガス警報器は、ガス検知素子として
熱線型半導体素子を用い、この熱線型半導体素子Ｋ、分
単位の周期で秒単位持続させる間欠通電部を介して電力
の供給を行わせ、出力回路によって熱的安定前の過渡時
の出力を検出する構成としたものである。This gas alarm using dAVc uses a hot-wire type semiconductor element as a gas detection element, and this hot-wire type semiconductor element K is supplied with electric power via an intermittent energization section that lasts for seconds at a period of minutes, and outputs The configuration is such that a circuit detects the output during a transient period before thermal stabilization.
この発明においては、間欠通電部を介して電源から熱線
型半導体素子に電力が供給される。供給されろ電力は数
分間ごとに数秒というようなごく短時間の電力であるが
、熱線型半導体素子を用いているので、通電された瞬間
からの熱的安定に至る過渡状態中でガス検出が行われる
。In this invention, power is supplied from the power supply to the hot-wire type semiconductor element via the intermittent current-carrying section. The electricity supplied is for a very short period of time, such as for a few seconds every few minutes, but since it uses a hot-wire semiconductor element, gas detection is possible during a transient state that reaches thermal stability from the moment the electricity is turned on. It will be done.
まず、この発明に用いる熱線型半導体素子について説明
する。First, a hot wire type semiconductor element used in the present invention will be explained.
第２図はこの発明に用いる熱線型半導体素子の構成を示
すもので、１は加熱用ヒータ兼電気抵抗値変化検出用電
極となる、例えば１５μｍφ の白金線からなるコイル
状の金属線、２は前記金属線１に密着させｙ、＝ｓｎｏ
、、ＺｎＯ等の金属酸化物半導体であり、これらで熱線
型半導体素子３が構成される。４はリードと支柱兼用の
金属ビンで、これに金属線１の両端が溶着され支持され
ている。FIG. 2 shows the configuration of the hot wire type semiconductor device used in the present invention, in which 1 is a coiled metal wire, for example, a platinum wire with a diameter of 15 μm, which serves as a heater for heating and an electrode for detecting changes in electrical resistance; In close contact with the metal wire 1, y,=sno
, , ZnO and other metal oxide semiconductors, and the hot wire type semiconductor element 3 is composed of these. Reference numeral 4 denotes a metal bottle that serves both as a lead and as a support, to which both ends of the metal wire 1 are welded and supported.
この熱線製半導体素子は、応答速度が極めて速く、初期
安定時間が極めて短い。またヒートショックに強く、消
費電力が少なく、感度が高く、かつ触媒劣化がない等の
特長を有している。This hot wire semiconductor element has an extremely fast response speed and an extremely short initial stabilization time. It also has features such as resistance to heat shock, low power consumption, high sensitivity, and no catalyst deterioration.
第２図に示す熱ａｍ半導体素子を用いて構成したこの発
明の一実施例を第１図に示す。An embodiment of the present invention constructed using the thermal am semiconductor element shown in FIG. 2 is shown in FIG.
第１図において、Ｒ１は抵抗器、３Ａは補償素子であり
、熱ｌｔＡ型半導体素子３とともにズリツジ回路を構成
している。なお、補償素子３Ａは第１図の熱線型半導体
素子３と同じ形状であるが、ガスとは反応しないように
表面ｔガラス等で被覆し工いる。Ｅは電池、Ｒ１は信号
検出用の可変抵抗器であり、これらで抵抗値変化の検知
回路１０が構成されるｃｌｌは間欠通電部であり、分単
位の周期で、秒単位持続する通電をくり返す５例えば第
３図に示すよう罠、２〜３分の間隔で１〜２秒間持続す
るパルス状の通電を行うものである。In FIG. 1, R1 is a resistor, 3A is a compensation element, and together with the thermal ltA type semiconductor element 3, they form a slip circuit. The compensating element 3A has the same shape as the hot-wire type semiconductor element 3 shown in FIG. 1, but its surface is covered with T-glass or the like so that it does not react with gas. E is a battery, R1 is a variable resistor for signal detection, and cll, which constitutes the resistance value change detection circuit 10, is an intermittent energization section, which provides energization that lasts for seconds at a cycle of minutes. For example, as shown in FIG. 3, a pulsed current is applied at intervals of 2 to 3 minutes for 1 to 2 seconds.
次に動作について脱Ｍｊる。第３図に示す波形のように
間欠通電部１１Ｙ通じて１〜２秒の間、つまり、いわゆ
る熱的安定前の過渡時Ｉ／ｃおいて、電池Ｅから電力が
供給され又いるとｐＫ被、検ガスが熱縁型半導体素子３
に＊触すると、金属酸化物半導体２は電導度が上がり、
まに熱伝導度も良くなるため温度が下がる。したがつ工
、金属線１の抵抗値も下がる。丁なわち、熱ＩＩｊ型半
導体素子３の抵抗値が低くなり、ブリッジ回路のバラン
スがくずれ工これが可変抵抗器Ｒｊ両両端用力（センサ
出カンとなって表われる。以後、この出力を用いて警報
器、換気扇等を駆動させればよい。Next, let's talk about the action. As shown in the waveform shown in FIG. 3, when power is supplied from the battery E through the intermittent current-carrying section 11Y for 1 to 2 seconds, that is, at the so-called transient time I/c before thermal stabilization, the pK is applied. , the detection gas is a hot-edge type semiconductor device 3
*When touched, the conductivity of the metal oxide semiconductor 2 increases,
It also improves thermal conductivity, which lowers the temperature. However, the resistance value of the metal wire 1 also decreases. In other words, the resistance value of the heat II type semiconductor element 3 decreases, causing the bridge circuit to become unbalanced. All you have to do is drive a ventilator, ventilation fan, etc.
第４図はこの発明忙よるガス検出のデータの一例を示す
もので、横軸は時間（秒）、縦軸はセンサ出力（ｍＶ）
を表わすＣ
曲ＩｗｌＡは空気中での出力を示し、！！源ＯＮの直後
に現われた出力は急激に減擬し工、電源ＯＦＦで零にな
る。Figure 4 shows an example of gas detection data according to this invention, where the horizontal axis is time (seconds) and the vertical axis is sensor output (mV).
C representing the song IwlA represents the output in the air, ! ! The output that appears immediately after the power is turned on rapidly decreases and becomes zero when the power is turned off.
曲［８はＣＯ２ガスとＨ，ガスの混合ガス中の場合であ
り、ＣＯｔガスは２００ｐｐｍ 、 Ｈ，ガスは４００
１ｍとした混合ガスの場合である。曲線Ａの空気中の場
合と違って出力値が大きくなり１両者のピーク値の差が
ガス濃度Ｋ１１ｆ１当する。Song [8] is the case in a mixed gas of CO2 gas and H gas, COt gas is 200 ppm, H gas is 400 ppm.
This is the case of a mixed gas with a length of 1 m. Unlike in the case of curve A in air, the output value becomes large, and the difference between the two peak values corresponds to the gas concentration K11f1.
曲＊ＣはＣＯ，ガス１００ ｐｐｍ ＊ Ｈｔガス２０
０２２ｍ の混合ガスの場合である。この場合のピーク
値は曲ｍＡと曲１ＭＢのビークｆ直の丁度中間になり、
ガス検出が正確に行われていることがわかる。Song *C is CO, gas 100 ppm * Ht gas 20
This is the case for a mixed gas of 0.022m. In this case, the peak value is exactly between the peak f direct of song mA and song 1MB,
It can be seen that gas detection is performed accurately.
第５図はこの発明の一実施例の全体構成な示すブロック
図である。この図で、１０．１１は第１図忙示したのと
同じく検知回路１間欠通電部であり、間欠通１部１１は
、パルス幅と繰返し周期が可変できるパルス発生回路１
２と、このパルス発生回路１２から発生したパルスによ
って制御された軍刀を第１因、第２図に示す熱縁型半導
体素子３に印加するパワーコントａ−ル回路１３とから
なつ工いる。１４はコンパレータで、検知回路１Ｇの出
力とあらかじめ定めた基準値とｔ比較し、その差を出力
する。１５は出力回路で、コンパレータ１４の出力から
ガス濃度が警報レベルかどうかな判断し、警報レベルに
達していれば出力を出す。FIG. 5 is a block diagram showing the overall configuration of an embodiment of the present invention. In this figure, 10.11 is the intermittent energizing section of the detection circuit 1, as shown in FIG.
2, and a power control circuit 13 that applies the military sword controlled by the pulses generated from the pulse generating circuit 12 to the first factor, the hot-edge type semiconductor element 3 shown in FIG. A comparator 14 compares the output of the detection circuit 1G with a predetermined reference value t, and outputs the difference. 15 is an output circuit that judges whether the gas concentration is at the alarm level based on the output of the comparator 14, and outputs an output if it has reached the alarm level.
１６は警報回路、１７はランプ点滅等の警報表示器、１
Ｂはブザー、１９は電源回路である。16 is an alarm circuit, 17 is an alarm indicator such as a flashing lamp, 1
B is a buzzer, and 19 is a power supply circuit.
検知回路１０と間欠通電部１１１Ｌよるガス検知動作は
既に述べたとおりである。さて、検出されたガス濃度が
警報レベルに達して出力回路１５から出力が出ると、こ
れが警報回路１８に入り、これから警報表示器１７やブ
ザー１Ｂが駆動される。The gas detection operation by the detection circuit 10 and the intermittent energization section 111L is as described above. Now, when the detected gas concentration reaches the alarm level and an output is output from the output circuit 15, this enters the alarm circuit 18, and from this the alarm display 17 and the buzzer 1B are driven.
なお、電源回路１９は各部分へ所要の電源を供給する。Note that the power supply circuit 19 supplies necessary power to each part.
以上説明しによ５にこの発明は、熱Ｉｗ型半導体式ガス
検知素子を用いてガス警報器を構成しているため、ガス
検知素子そのものが応答速度が極めて速く、しかも、接
触燃焼式ガス検知素子のように触媒を利用していないの
で触媒劣化を起すことがない。しかも、この発明では熱
ａ型半導体素子の電源投入直後の過渡現象な利用してい
るので、感度に丁ぐれ、かつ安定性のよいガス検知を行
うことができる。さらに、パルス状の電源を熱線型半導
体式ガス警報器に供給するので、経時安定性や耐被毒性
が良くなると共忙、電源をＯＮ、ＯＦＦすることにより
、零値の安定化がはかれるばかりでなく、省電力の効果
も著しい利点がある。As explained above, the present invention constitutes a gas alarm using a thermal Iw type semiconductor type gas detection element. Since it does not use a catalyst like other elements, catalyst deterioration does not occur. Moreover, since the present invention utilizes the transient phenomenon immediately after the power is turned on of the thermal a-type semiconductor element, it is possible to perform gas detection with excellent sensitivity and stability. Furthermore, since pulsed power is supplied to the hot-wire type semiconductor gas alarm, stability over time and toxicity resistance are improved, and by turning the power ON and OFF, the zero value can be stabilized. However, there is a significant advantage in terms of power saving.
第１図はこの発明の一実施例を示す回路図、第２因はこ
の発明用量いる熱感型半導体式ガス警報器の一例を示す
図、ＷＬ３図はこの発明の電源の波形の一例を示す図、
第４図はこの発明のガス噴出のデータの一例を示す図、
第５図はこの発明の一実施例の全体構成を示すグロック
図である。
図中、１は金属線、２は金属酸化物半導体、３は熱縁型
半導体素子、３Ａは補償素子、４は金属ビン、Ｒｈ は
抵抗器、Ｒ１は可変抵抗器、εは電池、１０は検知回路
、１１は間欠通電部、１５は出力回路である。
し！二・
第１図
第２図
旦
第３図
第４図
手続補正書（自発）
昭和６０年 ５月１３日Figure 1 is a circuit diagram showing an embodiment of this invention, the second factor is a diagram showing an example of a heat-sensitive semiconductor type gas alarm using this invention, and Figure WL3 shows an example of the waveform of the power supply of this invention. figure,
FIG. 4 is a diagram showing an example of gas ejection data of this invention,
FIG. 5 is a block diagram showing the overall configuration of an embodiment of the present invention. In the figure, 1 is a metal wire, 2 is a metal oxide semiconductor, 3 is a hot-edge type semiconductor element, 3A is a compensation element, 4 is a metal bottle, Rh is a resistor, R1 is a variable resistor, ε is a battery, and 10 is a The detection circuit, 11 is an intermittent current-carrying section, and 15 is an output circuit. death! 2. Figure 1 Figure 2 Dan Figure 3 Figure 4 Procedural amendment (voluntary) May 13, 1985
Claims (1)
に金属酸化物半導体を密着して形成してなる熱線型半導
体素子を、電源に負荷を介して直列に接続し、前記熱線
型半導体素子のガス吸着による抵抗値変化を検知信号と
して取出す検知回路を設け、さらに少なくとも前記電源
から前記熱線型半導体素子への電力供給を分単位の周期
で、かつ秒単位持続させる間欠通電部と、前記熱線型半
導体素子の熱的安定前の過渡時の出力を検出する出力回
路を具備したことを特徴とする熱線型半導体式ガス警報
器。A hot wire type semiconductor element formed by closely adhering a metal oxide semiconductor to a metal wire that serves as a heater and an electrode for detecting changes in electrical resistance is connected in series to a power source via a load, and the hot wire type semiconductor element is a detection circuit that extracts a change in resistance value due to gas adsorption as a detection signal, and further includes an intermittent energization section that continues supplying power from at least the power source to the hot wire type semiconductor element at a cycle of minutes and seconds; What is claimed is: 1. A hot-wire type semiconductor gas alarm, characterized by comprising an output circuit for detecting a transient output before thermal stabilization of a type semiconductor element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4840785A JPS61209347A (en) | 1985-03-13 | 1985-03-13 | Hot wire type semiconductive gas alarm |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4840785A JPS61209347A (en) | 1985-03-13 | 1985-03-13 | Hot wire type semiconductive gas alarm |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61209347A true JPS61209347A (en) | 1986-09-17 |
| JPH0426702B2 JPH0426702B2 (en) | 1992-05-08 |
Family
ID=12802449
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4840785A Granted JPS61209347A (en) | 1985-03-13 | 1985-03-13 | Hot wire type semiconductive gas alarm |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61209347A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01206248A (en) * | 1988-02-12 | 1989-08-18 | Figaro Eng Inc | Detecting method of imperfect combustion and apparatus therefor |
| JPH01206249A (en) * | 1988-02-12 | 1989-08-18 | Figaro Eng Inc | Method of detecting fire and apparatus therefor |
| JPH01206252A (en) * | 1988-02-12 | 1989-08-18 | Figaro Eng Inc | Method of detecting gas and apparatus therefor |
| JPH01316652A (en) * | 1988-02-02 | 1989-12-21 | Figaro Eng Inc | Gas detector |
| EP1189055A2 (en) * | 2000-09-14 | 2002-03-20 | Riken Keiki Co., Ltd. | Gas detector-alarm employing hot-wire gas sensor |
| JP2006017681A (en) * | 2004-07-05 | 2006-01-19 | Noritz Corp | Humidity detector |
| JP2009042166A (en) * | 2007-08-10 | 2009-02-26 | Toyota Central R&D Labs Inc | Gas detector |
| JP2009295095A (en) * | 2008-06-09 | 2009-12-17 | Yazaki Corp | Gas leak alarm |
| JP2009295094A (en) * | 2008-06-09 | 2009-12-17 | Yazaki Corp | Gas leak alarm |
| JP2009295096A (en) * | 2008-06-09 | 2009-12-17 | Yazaki Corp | Gas leak alarm |
| JP2009295093A (en) * | 2008-06-09 | 2009-12-17 | Yazaki Corp | Gas leak alarm |
-
1985
- 1985-03-13 JP JP4840785A patent/JPS61209347A/en active Granted
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01316652A (en) * | 1988-02-02 | 1989-12-21 | Figaro Eng Inc | Gas detector |
| JPH01206248A (en) * | 1988-02-12 | 1989-08-18 | Figaro Eng Inc | Detecting method of imperfect combustion and apparatus therefor |
| JPH01206249A (en) * | 1988-02-12 | 1989-08-18 | Figaro Eng Inc | Method of detecting fire and apparatus therefor |
| JPH01206252A (en) * | 1988-02-12 | 1989-08-18 | Figaro Eng Inc | Method of detecting gas and apparatus therefor |
| EP1189055A2 (en) * | 2000-09-14 | 2002-03-20 | Riken Keiki Co., Ltd. | Gas detector-alarm employing hot-wire gas sensor |
| EP1189055A3 (en) * | 2000-09-14 | 2002-11-27 | Riken Keiki Co., Ltd. | Gas detector-alarm employing hot-wire gas sensor |
| JP2006017681A (en) * | 2004-07-05 | 2006-01-19 | Noritz Corp | Humidity detector |
| JP2009042166A (en) * | 2007-08-10 | 2009-02-26 | Toyota Central R&D Labs Inc | Gas detector |
| JP2009295095A (en) * | 2008-06-09 | 2009-12-17 | Yazaki Corp | Gas leak alarm |
| JP2009295094A (en) * | 2008-06-09 | 2009-12-17 | Yazaki Corp | Gas leak alarm |
| JP2009295096A (en) * | 2008-06-09 | 2009-12-17 | Yazaki Corp | Gas leak alarm |
| JP2009295093A (en) * | 2008-06-09 | 2009-12-17 | Yazaki Corp | Gas leak alarm |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0426702B2 (en) | 1992-05-08 |
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