JPH0712771A - Gas detector - Google Patents
Gas detectorInfo
- Publication number
- JPH0712771A JPH0712771A JP15838793A JP15838793A JPH0712771A JP H0712771 A JPH0712771 A JP H0712771A JP 15838793 A JP15838793 A JP 15838793A JP 15838793 A JP15838793 A JP 15838793A JP H0712771 A JPH0712771 A JP H0712771A
- Authority
- JP
- Japan
- Prior art keywords
- heater
- temperature
- gas
- resistance value
- ambient temperature
- 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.)
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Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、ガス検出器、より詳細
には、雰囲気中のガス検出をするのに、ヒータを用いて
ガス感応素子をガス検出温度（所定温度）まで上げ、該
ガス感応素子の該ガス検出温度での抵抗変化でガスを検
出するガス検出器に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas detector, and more particularly to detecting a gas in an atmosphere by raising a gas sensitive element to a gas detection temperature (predetermined temperature) by using a heater. The present invention relates to a gas detector that detects a gas by a resistance change of a sensitive element at the gas detection temperature.
【０００２】[0002]
【従来の技術】ガス検出器、例えば、半導体ガス検出器
は、ヒータで加熱した金属酸化物半導体（ガス感応素
子）、例えば、ＳｎＯ2に還元性ガスを反応させると抵
抗値が減少することを利用し、雰囲気中の、例えば、水
蒸気、アルコール、イソブタン、メタンガス、その他の
ガスを検出する。2. Description of the Related Art A gas detector, for example, a semiconductor gas detector, has a resistance value which decreases when a reducing gas is reacted with a metal oxide semiconductor (gas sensitive element) heated by a heater, for example, SnO 2. For example, water vapor, alcohol, isobutane, methane gas, or other gas in the atmosphere is detected.
【０００３】図３は、本発明が適用される片持梁構造に
形成されたガス検知器の一例を説明するための構成図
で、図３（ａ）は平面図、図３（ｂ）は図３（ａ）図の
Ｂ−Ｂ線断面図で、図中、１０は基板、１１は該基版１
０に形成された凹部、１２は前記基板１０の上に形成さ
れたシリコンチップの薄膜絶縁体で、該薄膜絶縁体１２
は前記凹部１１の上に片持梁式に張り出す張り出し部ま
たは前記凹部の上に両持梁式に架橋される橋架部１２を
有し、該張り出し部又は橋架部１２の上にヒータ１３及
び該ヒータ１３に近接してガス感応素子１４が設けられ
ている。なお、このガス感応素子１４は、具体的には、
前述のようにＳnＯ2の金属酸化物半導体である。前記凹
部１１、張り出し部１２、ヒータ１３、ガス感応素子１
４は、好ましくは、同一基板１０上に形成されている。3A and 3B are structural views for explaining an example of a gas detector formed in a cantilever structure to which the present invention is applied. FIG. 3A is a plan view and FIG. 3B is a plan view. 3 is a sectional view taken along the line BB of FIG. 3A, in which 10 is a substrate and 11 is the base plate 1.
0 is a concave portion, and 12 is a thin film insulator of a silicon chip formed on the substrate 10.
Has a cantilever overhang on the recess 11 or a bridge 12 bridged on the recess in a cantilever manner, and a heater 13 and a heater 13 on the overhang or bridge 12. A gas sensitive element 14 is provided near the heater 13. The gas-sensitive element 14 is specifically
It is S n O 2 in the metal oxide semiconductor as described above. The concave portion 11, the protruding portion 12, the heater 13, the gas sensitive element 1
4 are preferably formed on the same substrate 10.
【０００４】而して、ガス検出を行なうには、検出した
いガスに応じて、前記ヒータ１３を加熱し、前記ガス感
応素子１４を検出したいガスと反応しやすい温度にし、
例えば、雰囲気中の水蒸気の存在を検出したい時は、ヒ
ータ１３（＝ガス感応素子１４）の温度を約２５０℃
に、アルコール分を検出したい時は約３５０℃に、イソ
ブタン分を検出したい時は４００℃に、また、メタンガ
スを検出したい時は４５０℃にし、その時のガス感応素
子１４の抵抗の変化より前記検出したいガスが雰囲気中
に存在するか否かの検出を行なっていた。In order to detect the gas, the heater 13 is heated in accordance with the gas to be detected, and the gas sensitive element 14 is set to a temperature at which it easily reacts with the gas to be detected.
For example, when it is desired to detect the presence of water vapor in the atmosphere, the temperature of the heater 13 (= gas sensitive element 14) is set to about 250 ° C.
Further, when it is desired to detect the alcohol content, the temperature is about 350 ° C., when the isobutane content is to be detected, the temperature is 400 ° C., and when the methane gas is to be detected, the temperature is 450 ° C. It was detected whether or not the desired gas was present in the atmosphere.
【０００５】[0005]
【発明が解決しようとする課題】しかし、上記従来技術
によると、前記ヒータ１３を加熱するのに、雰囲気温度
を全く考慮せずに前記ヒータ１３に電力を与えているの
で、実際には、前記ヒータ１３がガス感応温度になって
いるか否か不明であり、正確な検出ができなかった。However, according to the above-mentioned conventional technique, since the heater 13 is heated without any consideration of the ambient temperature in heating the heater 13, the heater 13 is actually used. It was unclear whether or not the heater 13 was at the gas sensitive temperature, and accurate detection could not be performed.
【０００６】[0006]
【課題を解決するための手段】本発明は上記課題を解決
するために、（１）ガス検出素子を加熱するヒータを所
定温度（ガス感応温度）に加熱し、該所定温度のときの
ガス検出素子の抵抗値を測ることで雰囲気中のガスを検
出するガス検出器において、前記ヒータの抵抗値を測定
する手段と、該ヒータの雰囲気温度のときの抵抗値と所
定温度のときの抵抗値との差を求める演算手段と、前記
ヒータの抵抗値を前記差分上昇するに必要な電力を記憶
した記憶テーブルと、前記雰囲気温度と前記差分とによ
り前記記憶テーブルから前記ヒータに印加する電力を求
め、求めた電力を前記ヒータに印加する手段とを有する
ことを特徴としたものである。In order to solve the above problems, the present invention (1) heats a heater for heating a gas detection element to a predetermined temperature (gas sensitive temperature), and detects gas at the predetermined temperature. A gas detector for detecting a gas in an atmosphere by measuring a resistance value of an element, a means for measuring a resistance value of the heater, a resistance value of the heater at an ambient temperature and a resistance value at a predetermined temperature. Of the electric power required to increase the difference in the resistance value of the heater, the electric power applied to the heater from the storage table by the atmospheric temperature and the difference, And a means for applying the obtained electric power to the heater.
【０００７】[0007]
【作用】ガス感応素を加熱するヒータの雰囲気温度にお
ける抵抗値を測定し、該ヒータのガス検出時における抵
抗値と前記測定値との差を求め、その差により決まる電
力を前記ヒータに加えて該ヒータをガス検出温度にし、
もって、前記ガス感応素子を検出しようとするガスに高
感度に反応する温度にする。The resistance value of the heater for heating the gas sensing element at ambient temperature is measured, the difference between the resistance value when the heater detects the gas and the measured value is obtained, and the electric power determined by the difference is applied to the heater. Bring the heater to the gas detection temperature,
As a result, the gas sensitive element is set to a temperature at which it is sensitive to the gas to be detected.
【０００８】[0008]
【実施例】図２は、ヒータの抵抗値と温度との関係を示
し、Ｒ01，…，Ｒ05，…，Ｒ10等はその時の周囲の雰囲
気温度、例えば、５℃，…，２０℃，…，４５℃等での
抵抗値、ＲH1，ＲH2，ＲH3，ＲH4は、それぞれヒータを
所定温度、例えば、雰囲気中の水蒸気の量を検出しよう
とする時は、前述のように、２５０℃、アルコールの量
を検出しようとする時は３５０℃、イソブタンの量を検
出しようとする時は４００℃、メタンガスの量を検出し
ようとする時は４５０℃に加熱した時の抵抗値である。EXAMPLE FIG. 2 shows the relationship between the resistance value of the heater and the temperature. R 01 , ..., R 05 , ..., R 10 etc. are the ambient temperature at that time, for example, 5 ° C., ..., 20 ° C. , ..., the resistance value at 45 ° C., R H1 , R H2 , R H3 , and R H4 are as described above when the heater is to detect a predetermined temperature, for example, the amount of water vapor in the atmosphere. The resistance value when heated to 250 ° C., 350 ° C. when detecting the amount of alcohol, 400 ° C. when detecting the amount of isobutane, and 450 ° C. when detecting the amount of methane gas. is there.
【０００９】なお、前述の水蒸気、アルコール、イソブ
タン、メタンガス等を検出するには、前記ガス感応素子
１４を、表１に示す温度範囲に加熱すれば、これらのガ
スを感度よく検出することができ、前述の２５０℃、３
５０℃、４００℃、４５０℃から多少ずれても、それ程
問題ではない。In order to detect the above-mentioned water vapor, alcohol, isobutane, methane gas, etc., if the gas sensitive element 14 is heated to the temperature range shown in Table 1, these gases can be detected with high sensitivity. , 250 ℃ of the above, 3
Even if it deviates a little from 50 ° C, 400 ° C, and 450 ° C, it does not matter so much.
【００１０】[0010]
【表１】 [Table 1]
【００１１】ここで、今、周囲温度２５℃の時のヒータ
抵抗をＲH25とすれば、このヒータを２５０℃に上げた
時の抵抗ＲH250は、 ＲH250＝ＲH25（１＋ΔＴ） ただし、ΔＴ＝ガス検出時のヒータ温度−雰囲気温度 で表わされる。Now, assuming that the heater resistance at an ambient temperature of 25 ° C. is R H25 , the resistance R H250 when this heater is raised to 250 ° C. is R H250 = R H25 (1 + ΔT) where ΔT = Heater temperature when gas is detected-ambient temperature.
【００１２】上記の式から、ヒータの抵抗値を現在の雰
囲気温度（上記例では２５℃）の抵抗値ＲH25から、ガ
ス検出温度（上記例では、２５０℃）の抵抗値ＲH250に
上げるには、現在のヒータ抵抗値ＲH25と、所定温度と
現在温度との差ΔＴが分ればよいことが分る。From the above equation, the resistance value of the heater is increased from the resistance value R H25 at the current ambient temperature (25 ° C. in the above example) to the resistance value R H250 at the gas detection temperature (250 ° C. in the above example). It is necessary to know the current heater resistance value R H25 and the difference ΔT between the predetermined temperature and the current temperature.
【００１３】而して、前記ヒータの抵抗値は、ヒータに
該ヒータを加熱しない程度の小電流を流し、その時の電
圧、電流により容易に測定することができ、同時に、こ
の時の抵抗値より、周囲温度も算出することができる。
従って、別途、温度測定手段を設けることなく、ガス感
応素子を加熱するヒータを用いて、周囲雰囲気温度及び
その時の抵抗値、換言すれば、前記式において、
ＲH20，ΔＴを求めることができる。Thus, the resistance value of the heater can be easily measured by applying a small current to the heater so as not to heat the heater and measuring the voltage and current at that time. The ambient temperature can also be calculated.
Therefore, using a heater for heating the gas sensitive element without separately providing temperature measuring means, the ambient atmosphere temperature and the resistance value at that time, in other words, in the above equation,
R H20 and ΔT can be obtained.
【００１４】ここで、ヒータの抵抗と温度とは、比例関
係にあり、ヒータの温度は、該ヒータに加えたエネルギ
ーに比例するので、前記ΔＴは、該ヒータに印加する電
力に置き換えることができる。従って、表２に示すよう
に、周囲温度及びその時のヒータ抵抗とから、ヒータを
各所定温度ＲH1，ＲH2，ＲH3，ＲH4にするための電力Ｐ
を予め求めておけば、ヒータ抵抗により周囲温度を求め
ることにより、該ヒータを所定温度（ガス検出温度）に
するために該ヒータに印加する電力を求めることができ
る。Here, since the resistance of the heater and the temperature are in a proportional relationship, and the temperature of the heater is proportional to the energy applied to the heater, the ΔT can be replaced with the electric power applied to the heater. . Therefore, as shown in Table 2, the electric power P to bring the heater to each of the predetermined temperatures R H1 , R H2 , R H3 , and R H4 is obtained from the ambient temperature and the heater resistance at that time.
If the above is obtained in advance, the electric power applied to the heater in order to bring the heater to a predetermined temperature (gas detection temperature) can be obtained by obtaining the ambient temperature from the heater resistance.
【００１５】[0015]
【表２】 [Table 2]
【００１６】なお、表２には、周囲温度の検出を５℃の
範囲内で検出する例について示したが、それ以下の精度
で、或いは、それ以上の精度で検出するようにしてもよ
いことは容易に理解できよう。更に、表２より、例え
ば、周囲温度が２０℃と測定されたとすると、この２０
℃の雰囲気中における、例えば、水蒸気の量、アルコー
ルの量、イソブタンの量、メタンガスの量等を、ヒータ
に印加する電力をＰ15，Ｐ25，Ｐ35，Ｐ45と順次変える
ことにより、迅速にかつ容易に検出することができる。Although Table 2 shows an example of detecting the ambient temperature within the range of 5 ° C., it may be detected with an accuracy of less than that or with an accuracy of more than that. Is easy to understand. Further, from Table 2, assuming that the ambient temperature is measured as 20 ° C., the
For example, by changing the amount of water vapor, the amount of alcohol, the amount of isobutane, the amount of methane gas, etc. in the atmosphere of ℃, the electric power applied to the heater in the order of P 15 , P 25 , P 35 , P 45 It can be easily and easily detected.
【００１７】図１は、上述のごとき本発明を実施するの
に使用して好適な電気回路の一例を説明するための図
で、図中、１はヒータ１３の抵抗を測定する抵抗測定回
路、２は演算回路、３は表２に示したデータが記憶され
ている記憶テーブル、４は電力制御回路、５は電源で、
雰囲気中に含まれているガスを測定するには、まず、そ
の時の雰囲気におけるヒータ１３の抵抗を抵抗測定回路
１により測定する。このヒータ１３の抵抗測定により、
その時の雰囲気の温度を知ることができる。例えば、表
２において、この時測定されたヒータ１３の抵抗値がＲ
04であるならば、その時の雰囲気温度は、Ｔ04である。FIG. 1 is a diagram for explaining an example of an electric circuit suitable for use in carrying out the present invention as described above, in which 1 is a resistance measuring circuit for measuring the resistance of the heater 13, 2 is an arithmetic circuit, 3 is a storage table in which the data shown in Table 2 is stored, 4 is a power control circuit, 5 is a power source,
To measure the gas contained in the atmosphere, first, the resistance of the heater 13 in the atmosphere at that time is measured by the resistance measuring circuit 1. By measuring the resistance of the heater 13,
You can know the temperature of the atmosphere at that time. For example, in Table 2, the resistance value of the heater 13 measured at this time is R
If it is 04 , the ambient temperature at that time is T 04 .
【００１８】ここで、今、雰囲気中の水蒸気の量（湿
度）を測定しようとする時は、演算回路２により、水蒸
気の量を測定する時に必要なヒータ１３の加熱温度Ｔ1
（２５０℃）と前述のごとくして測定された雰囲気温度
Ｔ04（１５≦Ｔ04＜２０）との差を求める。この差を求
めるには、演算回路２に、図示例の場合、４つの基準抵
抗ＲH1，ＲH2，ＲH3，ＲH4を設けておき、測定しようと
するガスに応じて、前記４つの基準抵抗のうちの１つを
選び、この選ばれた基準抵抗と前述のごとくして測定し
た雰囲気温度における抵抗値との差を求める。Here, when it is desired to measure the amount of water vapor (humidity) in the atmosphere, the heating temperature T 1 of the heater 13 required when the amount of water vapor is measured by the arithmetic circuit 2 is measured.
The difference between (250 ° C.) and the ambient temperature T 04 (15 ≦ T 04 <20) measured as described above is calculated. In order to obtain this difference, in the illustrated example, four reference resistors R H1 , R H2 , R H3 , and R H4 are provided in the arithmetic circuit 2, and the four reference resistors are set according to the gas to be measured. One of the resistors is selected, and the difference between the selected reference resistor and the resistance value at the ambient temperature measured as described above is calculated.
【００１９】上述のごとくして、雰囲気温度、及び測定
しようとするガスに対応して加熱すべきヒータ温度と雰
囲気温度との差を求めると、これら雰囲気温度と差温度
より、テーブル３から該雰囲気温と差温度によって決る
電力を求める。前述の例（雰囲気温度＝２０℃、被測定
ガス＝水蒸気）の場合、Ｐ14が選択され、電力制御回路
４は、電源５の電力を該電力Ｐ14に制御し、この電力Ｐ
14をヒータ１３に印加する。すなわち、ヒータ１３は、
ガス感応素子１４が測定しようとするガスに最も感度よ
く感応する温度に加熱される。As described above, when the difference between the ambient temperature and the heater temperature to be heated and the ambient temperature corresponding to the gas to be measured is determined, the ambient temperature is calculated from Table 3 from the ambient temperature and the difference temperature. Find the power determined by the temperature and the temperature difference. In the case of the above example (ambient temperature = 20 ° C., gas to be measured = water vapor), P 14 is selected, and the power control circuit 4 controls the power of the power source 5 to the power P 14 , and this power P 14
14 is applied to the heater 13. That is, the heater 13 is
The gas sensitive element 14 is heated to a temperature at which the gas to be measured is most sensitive.
【００２０】上述のごとく、本発明によると、雰囲気温
度に応じてヒータに印加する電力をコントロールして、
雰囲気温度に影響されることなくヒータの温度を所定温
度（ガス感応素子が被測定ガスに感応しやすい温度）に
正確に加熱することができ、しかも、１回の雰囲気温度
の測定で、複数種類のガスを順次検出することができ
る。更に詳細に説明すると、本発明の実施に用いるガス
検出素子は、図３の従来技術に示したように、熱容器の
非常に小さいものであるので、ヒータ１３の加熱を遮断
すると、直ちに雰囲気温度に戻るので、演算回路の基準
抵抗をＲH1，ＲH2，ＲH3，ＲH4と比較的早く切換えるこ
とができ、水蒸気（湿度）の検出、アルコール分の検
出、イソブタン分の検出、メタン分の検出を順次かつ迅
速に行うことができる。As described above, according to the present invention, the electric power applied to the heater is controlled according to the ambient temperature,
The temperature of the heater can be accurately heated to a predetermined temperature (the temperature at which the gas sensitive element is sensitive to the gas to be measured) without being affected by the ambient temperature, and more than one type can be obtained by measuring the ambient temperature once. The gases can be sequentially detected. More specifically, since the gas detecting element used for implementing the present invention has a very small heat container as shown in the prior art of FIG. 3, when the heating of the heater 13 is cut off, the ambient temperature is immediately increased. Therefore, the reference resistance of the arithmetic circuit can be switched to R H1 , R H2 , R H3 , and R H4 relatively quickly, and the detection of water vapor (humidity), the detection of alcohol, the detection of isobutane, and the detection of methane The detection can be performed sequentially and quickly.
【００２１】更に、前述のごときガス検出素子は、高精
度をもって略均一の精度のものが作られるが、どうして
も、製品精度にばらつきが生じ、ヒータ１３の抵抗値が
必ずしも全ての製品で同じになるとは限らず、バラツキ
が生じる。しかし、ヒータ材料は全て同じであるので、
図２に示した温度−抵抗特性は、図中に点線にて示すよ
うに、その勾配が同じであるので、各素子に対して、任
意所望の温度における抵抗を測定することにより、テー
ブル３を簡単に作成することができ、ガス感応素子の特
性のバラツキに関係なく、ヒータ温度をガス検出に適し
た所望の温度に正確にすることができる。Further, the gas detecting element as described above is made with high accuracy and substantially uniform accuracy, but inevitably the product accuracy varies and the resistance value of the heater 13 is not always the same in all products. However, variations occur. However, since the heater materials are all the same,
The temperature-resistance characteristics shown in FIG. 2 have the same gradient as indicated by the dotted line in the figure, so that the resistance at each desired temperature is measured for each element, and the table 3 is obtained. It can be easily created, and the heater temperature can be accurately set to a desired temperature suitable for gas detection regardless of variations in the characteristics of the gas sensitive element.
【００２２】[0022]
【効果】以上の説明から明らかなように、本発明による
と、ガス検出素子のヒータ温度を、雰囲気温度の変動に
関係なく、被検出ガスの感応温度に正確にすることがで
き、しかも、ガス検出素子の特性のバラツキに影響され
ることなく、正確に被検出ガスの存在を検出することが
できる。As is apparent from the above description, according to the present invention, the heater temperature of the gas detecting element can be accurately adjusted to the sensitive temperature of the gas to be detected regardless of the fluctuation of the ambient temperature. The presence of the gas to be detected can be accurately detected without being affected by the variation in the characteristics of the detection element.
【図１】 本発明を実施するのに使用して好適な電気回
路の一例を説明するための図である。FIG. 1 is a diagram for explaining an example of an electric circuit suitable for use in implementing the present invention.
【図２】 ヒータの温度−抵抗特性図である。FIG. 2 is a temperature-resistance characteristic diagram of a heater.
【図３】 本発明を実施するのに使用して好適な従来の
ガス検出器の一例を説明するための図である。FIG. 3 is a diagram for explaining an example of a conventional gas detector suitable for use in implementing the present invention.
１…抵抗値測定手段、２…演算手段、３…データ記憶テ
ーブル、４…電力制御手段、５…電源、１０…ガス検出
器、１３…ヒータ、１４…ガス感応素子。1 ... Resistance value measuring means, 2 ... Calculation means, 3 ... Data storage table, 4 ... Power control means, 5 ... Power supply, 10 ... Gas detector, 13 ... Heater, 14 ... Gas sensitive element.
Claims (1)
度（ガス感応温度）に加熱し、該所定温度のときのガス
検出素子の抵抗値を測ることで雰囲気中のガスを検出す
るガス検出器において、前記ヒータの抵抗値を測定する
手段と、該ヒータの雰囲気温度のときの抵抗値と所定温
度のときの抵抗値との差を求める演算手段と、前記ヒー
タの抵抗値を前記差分上昇するに必要な電力を記憶した
記憶テーブルと、前記雰囲気温度と前記差分とにより前
記記憶テーブルから前記ヒータに印加する電力を求め、
求めた電力を前記ヒータに印加する手段とを有すること
を特徴とするガス検出器。1. A gas detector for detecting a gas in an atmosphere by heating a heater for heating a gas detection element to a predetermined temperature (gas sensitive temperature) and measuring a resistance value of the gas detection element at the predetermined temperature. In the above, the means for measuring the resistance value of the heater, the calculating means for obtaining the difference between the resistance value of the heater at ambient temperature and the resistance value of the heater at a predetermined temperature, and the resistance value of the heater are increased by the difference. A storage table storing the electric power required for the electric power to be applied to the heater from the storage table based on the ambient temperature and the difference,
And a means for applying the obtained electric power to the heater.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15838793A JP3300110B2 (en) | 1993-06-29 | 1993-06-29 | Gas detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15838793A JP3300110B2 (en) | 1993-06-29 | 1993-06-29 | Gas detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0712771A true JPH0712771A (en) | 1995-01-17 |
| JP3300110B2 JP3300110B2 (en) | 2002-07-08 |
Family
ID=15670618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15838793A Expired - Fee Related JP3300110B2 (en) | 1993-06-29 | 1993-06-29 | Gas detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3300110B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11248659A (en) * | 1998-03-04 | 1999-09-17 | Fuji Electric Co Ltd | Gas detecting alarm |
| JP2012164096A (en) * | 2011-02-04 | 2012-08-30 | Fuji Electric Co Ltd | Gas alarm and heater electric power control method of gas sensor in gas alarm |
| JP2012164094A (en) * | 2011-02-04 | 2012-08-30 | Fuji Electric Co Ltd | Gas alarm and heater voltage setting method of gas sensor in gas alarm |
| JP2012164095A (en) * | 2011-02-04 | 2012-08-30 | Fuji Electric Co Ltd | Gas alarm, and heater temperature control method of gas sensor in gas alarm |
| JP2012237642A (en) * | 2011-05-11 | 2012-12-06 | Honda Motor Co Ltd | Gas sensor |
-
1993
- 1993-06-29 JP JP15838793A patent/JP3300110B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11248659A (en) * | 1998-03-04 | 1999-09-17 | Fuji Electric Co Ltd | Gas detecting alarm |
| JP2012164096A (en) * | 2011-02-04 | 2012-08-30 | Fuji Electric Co Ltd | Gas alarm and heater electric power control method of gas sensor in gas alarm |
| JP2012164094A (en) * | 2011-02-04 | 2012-08-30 | Fuji Electric Co Ltd | Gas alarm and heater voltage setting method of gas sensor in gas alarm |
| JP2012164095A (en) * | 2011-02-04 | 2012-08-30 | Fuji Electric Co Ltd | Gas alarm, and heater temperature control method of gas sensor in gas alarm |
| JP2012237642A (en) * | 2011-05-11 | 2012-12-06 | Honda Motor Co Ltd | Gas sensor |
| US9017612B2 (en) | 2011-05-11 | 2015-04-28 | Honda Motor Co., Ltd. | Gas sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3300110B2 (en) | 2002-07-08 |
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