JP3114137B2 - Thermal conductivity gas concentration analyzer - Google Patents
Thermal conductivity gas concentration analyzerInfo
- Publication number
- JP3114137B2 JP3114137B2 JP06066528A JP6652894A JP3114137B2 JP 3114137 B2 JP3114137 B2 JP 3114137B2 JP 06066528 A JP06066528 A JP 06066528A JP 6652894 A JP6652894 A JP 6652894A JP 3114137 B2 JP3114137 B2 JP 3114137B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- thermal conductivity
- temperature
- output voltage
- constant
- 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 - Lifetime
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- Investigating Or Analyzing Materials Using Thermal Means (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は、試料ガスに含まれる
測定対象ガスの濃度を測定する熱伝導率式ガス濃度分析
計に関するものである。BACKGROUND OF THE INVENTION This invention is included in the sample gas
Thermal conductivity gas concentration analysis to measure the concentration of the gas to be measured
It is about a total .
【０００２】[0002]
【従来の技術】従来より、石油精製，石油化学，鉄鋼な
どのプラントに使用される熱伝導率式ガス濃度分析計と
して、その要部を図３に示すような熱伝導率式水素濃度
計が用いられている。同図において、１は試料ガス（例
えば、測定対象ガスとしてＨ2ガス、共存ガスとしてＮ
2 ガスを含むガス）の給送通路に配置された第１の測温
抵抗体（ＴＣＤ）、２は熱伝導率が既知のリファレンス
ガスの給送通路に配置された第２の測温抵抗体（ＴＣ
Ｄ）、Ｒ１，Ｒ２は抵抗、３は比較器、４は定電流源又
は定電圧源であり、ＴＣＤ１，ＴＣＤ２，抵抗Ｒ１，Ｒ
２によりホイートストンブリッジが組まれている。2. Description of the Related Art Conventionally, a thermal conductivity type gas concentration analyzer used in a plant for petroleum refining, petrochemical, steel, etc., has a heat conduction type gas concentration analyzer as shown in FIG. Rate formula hydrogen concentration
Meter is used. In FIG. 1, reference numeral 1 denotes a sample gas (for example, H 2 gas as a gas to be measured and N as a coexisting gas).
A first resistance thermometer (TCD) disposed in a supply passage of a gas containing two gases), and a second resistance temperature detector (TCD) disposed in a supply passage of a reference gas having a known thermal conductivity. (TC
D), R1 and R2 are resistors, 3 is a comparator, 4 is a constant current source or a constant voltage source, TCD1, TCD2, resistors R1, R
A Wheatstone bridge is formed by the two.
【０００３】この熱伝導率式水素濃度計では、試料ガス
がＴＣＤ１に給送され、その熱伝導率に比例した熱を奪
う。これにより、ＴＣＤ１の発熱温度が変化し、その抵
抗値が変化する。一方、ＴＣＤ２には、リファレンスガ
スが給送されている。この場合、リファレンスガスの熱
伝導率は一定であるから、リファレンスガスによって奪
われる熱も一定であり、ＴＣＤ２の発熱温度は一定とな
り、その抵抗値は一定となる。抵抗Ｒ１とＴＣＤ１との
接続点に生ずる電圧は比較器３の非反転入力へ、抵抗Ｒ
２とＴＣＤ２との接続点に生ずる電圧は比較器３の反転
入力へ与えられる。これにより、試料ガスとリファレン
スガスの熱伝導率の差に比例した抵抗値変化（発熱温度
の差）が、不平衡電圧ΔＶとして検出される。ここで、
リファレンスガスを試料ガスに含まれる共存ガスと同一
成分（Ｎ2 ガス）とすれば、検出される不平衡電圧ΔＶ
に基づいて予め設定されている検量線を参照として、試
料ガスに含まれているＨ2 ガスの濃度を測定することが
できる。[0003] In this thermal conductivity type hydrogen concentration meter , a sample gas is fed to the TCD 1 to remove heat proportional to the thermal conductivity. As a result, the heat generation temperature of the TCD 1 changes, and the resistance value changes. On the other hand, a reference gas is supplied to the TCD 2. In this case, since the thermal conductivity of the reference gas is constant, the heat taken by the reference gas is also constant, the heat generation temperature of the TCD 2 is constant, and the resistance value is constant. The voltage generated at the connection point between the resistors R1 and TCD1 is applied to the non-inverting input of the comparator 3 and the resistor R
The voltage generated at the node between TCD2 and TCD2 is applied to the inverting input of comparator 3. Thus, a change in resistance value (difference in heat generation temperature) in proportion to the difference in thermal conductivity between the sample gas and the reference gas is detected as the unbalanced voltage ΔV. here,
If the reference gas is the same component (N 2 gas) as the coexisting gas contained in the sample gas, the detected unbalanced voltage ΔV
The concentration of H 2 gas contained in the sample gas can be measured with reference to a calibration curve set in advance based on.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、このよ
うな従来の熱伝導率式ガス濃度分析計では、不平衡電圧
ΔＶと測定対象ガスの濃度との関係を示す検量線を分析
計毎に固有に作成しており、このため多種類の校正ガス
を必要とし、その校正，調整（リニアライズ）に時間を
要するという問題があった。例えば、上述した熱伝導率
式水素濃度計について言えば、濃度（既知濃度）の異な
るＨ2 ガス（共存ガスはＮ2 ガス）を校正ガスとして多
数用意し、これら校正ガスをＴＣＤ１へ給送して不平衡
電圧ΔＶを検出するものとし、この検出された各校正ガ
スの不平衡電圧ΔＶとＨ2 ガス濃度との関係をプロット
して検量線を作成している。ここで、この作成される検
量線は、水素濃度計毎にその装置定数が異なるため、共
通として使用することはできない。このため、水素濃度
計毎に検量線を固有に作成しており、多種類の校正ガス
を必要とし、その校正，調整に時間を要するという問題
が生ずる。However, in such a conventional thermal conductivity type gas concentration analyzer , a calibration curve indicating the relationship between the unbalanced voltage ΔV and the concentration of the gas to be measured is uniquely assigned to each analyzer. Therefore, there is a problem that many kinds of calibration gases are required, and it takes time for calibration and adjustment (linearization). For example, in the case of the above-described thermal conductivity type hydrogen concentration meter , a large number of H 2 gases (coexisting gas is N 2 gas) having different concentrations (known concentrations) are prepared as calibration gases, and these calibration gases are supplied to the TCD 1. To detect the unbalanced voltage ΔV, and the calibration curve is created by plotting the relationship between the detected unbalanced voltage ΔV of each calibration gas and the H 2 gas concentration. Here, the calibration curve created cannot be used in common because the apparatus constants are different for each hydrogen concentration meter . Therefore, the hydrogen concentration
Since a calibration curve is uniquely created for each meter , various kinds of calibration gas are required, and there is a problem that time is required for calibration and adjustment.
【０００５】本発明はこのような課題を解決するために
なされたもので、その目的とするところは、固有の検量
線を用いることなく測定対象ガスの濃度を測定すること
ができ、校正，調整に要する時間の短縮化を図ることの
できる熱伝導率式ガス濃度分析計を提供することにあ
る。The present invention has been made to solve such a problem, and an object of the present invention is to measure the concentration of a gas to be measured without using a specific calibration curve.
To reduce the time required for calibration and adjustment.
It is an object of the present invention to provide a thermal conductivity type gas concentration analyzer which can be used .
【０００６】[0006]
【課題を解決するための手段】このような目的を達成す
るために、本発明は、試料ガスの給送通路に配置された
測温抵抗体と、この測温抵抗体の温度変化を出力電圧ｖ
の変化として検出し、この検出される出力電圧ｖの変化
に基づいて測温抵抗体へのエネルギーの供給量を制御し
その発熱温度を一定値に保つ制御手段と、この制御手段
によりその発熱温度が一定値に保たれた状態での出力電
圧ｖを固有の装置定数を含む所定の演算式に代入して試
料ガスの熱伝導率を算出する熱伝導率算出手段と、この
熱伝導率算出手段の算出した熱伝導率に基づき、試料ガ
スに含まれる測定対象ガスおよび共存ガスの種類に応じ
て定められている試料ガスの熱伝導率に対する測定対象
ガスの濃度を示す検量線を参照として測定対象ガスの濃
度を導出する濃度導出手段とを備えたものである。ここ
で、熱伝導率算出手段における演算式中の固有の装置定
数は、既知の熱伝導率λ１の第１の校正ガスを測温抵抗
体へ給送して制御手段によりその発熱温度が一定値に保
たれた状態での出力電圧ｖ１を測定し、既知の熱伝導率
λ２（λ１≠λ２）の第２の校正ガスを測温抵抗体へ給
送して制御手段によりその発熱温度が一定値に保たれた
状態での出力電圧ｖ２を測定し、これら測定した出力電
圧ｖ１，ｖ２および熱伝導率λ１，λ２に基づいて定め
ている。SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a temperature measuring resistor disposed in a sample gas supply passage and an output voltage measuring device for detecting a temperature change of the temperature measuring resistor. v
Control means for controlling the amount of energy supplied to the resistance temperature detector based on the detected change in the output voltage v to maintain the heat generation temperature at a constant value; and Thermal conductivity calculating means for calculating the thermal conductivity of the sample gas by substituting the output voltage v in a state where is maintained at a constant value into a predetermined arithmetic expression including a unique device constant ,
Based on the thermal conductivity calculated by the thermal conductivity calculation means,
According to the type of gas to be measured and coexisting gas
Of measurement for the thermal conductivity of the sample gas specified in
Refer to the calibration curve showing the gas concentration
Density deriving means for deriving the degree . Here, the intrinsic device constant in the arithmetic expression in the thermal conductivity calculating means is such that the first calibration gas having a known thermal conductivity λ1 is supplied to the temperature measuring resistor, and the heating temperature is controlled by the control means to a constant value. Is measured, the second calibration gas having a known thermal conductivity λ2 (λ1 ≠ λ2) is supplied to the resistance temperature detector, and the control unit controls the heat generation temperature to a constant value. The output voltage v2 in the state where the voltage is maintained at is maintained, and the output voltage v2 is determined based on the measured output voltages v1 and v2 and the thermal conductivity λ1 and λ2.
【０００７】[0007]
【作用】したがってこの発明によれば、試料ガスを測温
抵抗体へ給送すると、この測温抵抗体の温度変化が出力
電圧ｖの変化として検出され、この検出される出力電圧
ｖの変化に基づいて測温抵抗体へのエネルギーの供給量
が制御され、その発熱温度が一定値に保たれる。そし
て、発熱温度が一定値に保たれた状態での出力電圧ｖが
固有の装置定数を含む所定の演算式に代入され、試料ガ
スの熱伝導率が算出される。この算出された熱伝導率に
基づき、試料ガスに含まれる測定対象ガスおよび共存ガ
スの種類に応じて定められている試料ガスの熱伝導率に
対する測定対象ガスの濃度を示す検量線を参照として、
測定対象ガスの濃度が導出される。この場合、固有のも
のとしては、熱伝導率算出手段における演算式中の装置
定数を、既知の熱伝導率λ１の第１の校正ガスおよび既
知の熱伝導率λ２の第２の校正ガスを測温抵抗体へ給送
して出力電圧ｖ１およびｖ２を測定し、これら測定した
出力電圧ｖ１，ｖ２および熱伝導率λ１，λ２に基づい
て定めてやるのみでよい。Therefore, according to the present invention, when the sample gas is fed to the resistance temperature detector, a temperature change of the resistance temperature detector is detected as a change in the output voltage v, and the change in the detected output voltage v is detected. The amount of energy supplied to the resistance temperature detector is controlled based on this, and the heat generation temperature is maintained at a constant value. Then, the output voltage v in a state where the heat generation temperature is kept at a constant value is
The thermal conductivity of the sample gas is calculated by substituting into a predetermined arithmetic expression including a unique device constant . Based on the calculated thermal conductivity, the thermal conductivity of the sample gas is determined according to the type of the measurement target gas and the coexisting gas contained in the sample gas.
With reference to the calibration curve indicating the concentration of the gas to be measured,
The concentration of the gas to be measured is derived. In this case, the device constants in the arithmetic expressions in the thermal conductivity calculating means are uniquely measured by measuring the first calibration gas having a known thermal conductivity λ1 and the second calibration gas having a known thermal conductivity λ2. It is only necessary to measure the output voltages v1 and v2 by feeding them to the thermal resistor and determine them based on the measured output voltages v1 and v2 and the thermal conductivity λ1 and λ2.
【０００８】[0008]
【実施例】以下、本発明を実施例に基づき詳細に説明す
る。図１はこの発明に係る熱伝導率式水素濃度計の要部
を示す図である。同図において、１は試料ガス（例え
ば、測定対象ガスとしてＨ2 ガス、共存ガスとしてＮ2
ガスを含むガス）の給送通路に配置された測温抵抗体
（ＴＣＤ）、Ｒ１，Ｒ２，Ｒ３は抵抗、３は比較器、４
は熱伝導率算出部、５は濃度導出部、６はＲＯＭであ
り、ＴＣＤ１，抵抗Ｒ１，Ｒ２，Ｒ３により恒温槽７内
でホイートストンブリッジが組まれている。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. FIG. 1 is a view showing a main part of a thermal conductivity type hydrogen concentration meter according to the present invention. In FIG. 1, reference numeral 1 denotes a sample gas (for example, H 2 gas as a gas to be measured and N 2 gas as a coexisting gas).
(TCD) disposed in the feed path of gas containing gas, R1, R2, and R3 are resistors, 3 is a comparator,
Is a thermal conductivity calculating unit, 5 is a concentration deriving unit, 6 is a ROM, and a Wheatstone bridge is formed in the thermostat 7 by the TCD1, the resistors R1, R2, and R3.
【０００９】この熱伝導率式水素濃度計では、試料ガス
がＴＣＤ１に給送され、その熱伝導率に比例した熱を奪
う。これにより、ＴＣＤ１の発熱温度ＴRhが変化し、そ
の抵抗値Ｒｈが変化する。抵抗Ｒ１とＴＣＤ１との接続
点に生ずる電圧は出力電圧ｖとして比較器３の反転入力
へ、抵抗Ｒ３とＲ２との接続点に生ずる電圧は比較器３
の非反転入力へ与えられる。これにより、ＴＣＤ１の温
度変化が、出力電圧ｖの変化Δｖとして検出される。比
較器３は、この検出した出力電圧ｖの変化Δｖに基づい
て、ＴＣＤ１へ流れる電流ｉを制御し、ＴＣＤ１の抵抗
値Ｒｈを一定（Ｒｈ＝（Ｒ１×Ｒ２）／Ｒ３）に保つ。
これにより、出力電圧ｖが変化し、ＴＣＤ１の発熱温度
ＴRhが一定に保たれる。In this thermal conductivity type hydrogen concentration meter , the sample gas is fed to the TCD 1 and takes away heat proportional to the thermal conductivity. As a result, the heat generation temperature T Rh of the TCD 1 changes, and the resistance value Rh changes. The voltage generated at the connection point between the resistors R1 and TCD1 is output to the inverting input of the comparator 3 as the output voltage v, and the voltage generated at the connection point between the resistors R3 and R2 is calculated as the output voltage v.
To the non-inverting input of Thereby, the temperature change of TCD1 is detected as the change Δv of the output voltage v. The comparator 3 controls the current i flowing to the TCD1 based on the detected change Δv of the output voltage v, and keeps the resistance Rh of the TCD1 constant (Rh = (R1 × R2) / R3).
As a result, the output voltage v changes, and the heat generation temperature T Rh of the TCD 1 is kept constant.
【００１０】ＴＣＤ１の発熱温度ＴRhが一定に保たれる
ことは下記（１）式を見ても分かる。すなわち、ＴＣＤ
１は白金薄膜抵抗体であり、その抵抗値Ｒｈは（１）式
で示され、ＴＣＤ１の抵抗値Ｒｈを一定に制御すれば、
同時に発熱温度ＴRhも一定に保たれる。 Ｒｈ＝Ｒｈ20｛１＋α20・（ＴRh−２０）＋β20・（ＴRh−２０）2 ｝ ・・ ・（１） なお、この式において、Ｒｈ20は２０℃におけるＴＣＤ
１の抵抗値（Ω）、α20は２０℃におけるＴＣＤ１の１
次抵抗温度係数、β20は２０℃におけるＴＣＤ１の２次
抵抗温度係数である。The fact that the exothermic temperature T Rh of the TCD 1 is kept constant can also be seen from the following equation (1). That is, TCD
Reference numeral 1 denotes a platinum thin film resistor, and its resistance Rh is expressed by the following equation (1). If the resistance Rh of the TCD 1 is controlled to be constant,
At the same time, the exothermic temperature T Rh is kept constant. Rh = Rh 20 {1 + α 20 · (T Rh -20) + β 20 · (T Rh -20) 2} ·· · (1) Note that, in this formula, Rh 20 is TCD at 20 ° C.
The resistance value (Ω) of 1 and α 20 is 1 of TCD1 at 20 ° C.
The secondary resistance temperature coefficient, β 20, is the secondary resistance temperature coefficient of TCD1 at 20 ° C.
【００１１】ここで、ＴＣＤ１から周囲に伝わる熱量Ｑ
T は、下記（２）式で示される。なお、この式におい
て、ＱG は熱伝導により試料ガスに伝わる熱量、ＱS は
ＴＣＤ１を構築するダイヤフラム（シリコン）および抵
抗パターンを通してシリコン台座に伝わる熱量、ＱC は
対流（強制対流および自然対流）により伝わる熱量、Ｑ
R は輻射により伝わる熱量である。 ＱT ＝ＱG ＋ＱS ＋ＱC ＋ＱR ・・・（２） この熱量ＱT は、さらに、下記（３）式として表現され
る。なお、この式において、ＴRR2 は恒温槽７の温度
（℃）、λｍは試料ガスの熱伝導率（ｗ／ｋ・ｍ）、Ｇ
は装置定数（ｍ）、λsiはダイヤフラムおよび抵抗パタ
ーンの熱伝導率（ｗ／ｋ・ｍ）、ＧS はダイヤフラムお
よび抵抗パターンにおける装置定数（ｍ）である。Here, the heat quantity Q transmitted from the TCD 1 to the surroundings
T is represented by the following equation (2). Note that, in this formula, Q G is the amount of heat transferred to the sample gas by heat conduction, Q S is the amount of heat transferred to the silicon base through the diaphragm (silicon) and the resistor pattern to build TCD 1, Q C convection (forced convection and natural convection) The amount of heat transmitted by Q
R is the amount of heat transmitted by radiation. Q T = Q G + Q S + Q C + Q R (2) The heat quantity Q T is further expressed by the following equation (3). In this equation, T RR2 is the temperature of the thermostat 7 (° C.), λm is the thermal conductivity of the sample gas (w / km), G
The apparatus constant (m), the lambda si thermal conductivity of the diaphragm and resistor pattern (w / k · m), G S is a device constant in the diaphragm and resistor pattern (m).
【００１２】 ＱT ＝（ＴRh−ＴRR2 ）・λｍ・Ｇ＋（ＴRh−ＴRR2 ）・λsi・ＧS ＋ＱC ＋ＱR ・・・（３） この（３）式において、ＧおよびＧS はガス組成によっ
て変化しないし、ＱC，ＱR はＱG ，ＱS に比べて十分
小さな値（または一定値）であり、λsiも一定と考えら
れる。また、ＴRh，ＴRR2 は一定にコントロールされる
ので、上記（３）式はＡ，Ｂを固有の装置定数（運転状
態を含めた形状係数）として、下記（４）式で示され
る。 ＱT ＝Ａ・λｍ＋Ｂ ・・・（４） 一方、ＱT は、 ＱT ＝ｉ2 ・Ｒｈ＝ｖ2 ／Ｒｈ ・・・（５） として表され、ＱT ＝Ａ・λｍ＋Ｂ＝ｖ2 ／Ｒｈより、
試料ガスの熱伝導率λｍは下記（６）式で表されるもの
となる。 λｍ＝（ｖ2 ／Ｒｈ−Ｂ）／Ａ ・・・（６）Q T = (T Rh −T RR2 ) · λm · G + (T Rh −T RR2 ) · λ si · G S + Q C + Q R (3) In the equation (3), G and G S is do not vary with gas composition, Q C, Q R is sufficiently small value compared to the Q G, Q S (or constant value), lambda si also considered constant. Further, since T Rh and T RR2 are controlled to be constant, the above equation (3) is expressed by the following equation (4), where A and B are intrinsic device constants (shape factors including the operating state). Q T = A · λm + B (4) On the other hand, Q T is expressed as Q T = i 2 · Rh = v 2 / Rh (5), and Q T = A · λm + B = v 2 / From Rh,
The thermal conductivity λm of the sample gas is represented by the following equation (6). λm = (v 2 / Rh−B) / A (6)
【００１３】ここで、固有の装置定数Ａ，Ｂが分かれ
ば、出力電圧ｖを上記（６）式に代入することにより、
試料ガスの熱伝導率λｍを求めることができる。そこ
で、本実施例においては、上記（６）式を演算式として
熱伝導率算出部４へ設定する一方、この演算式における
固有の装置定数Ａ，Ｂを次のようにして定めている。す
なわち、熱伝導率が既知の第１の校正ガス（例えば、１
００％Ｎ2 ガス）をＴＣＤ１へ給送して出力電圧ｖ（ｖ
N2＝ｖ１）を測定し、熱伝導率が既知の第２の校正ガス
（例えば、１００％Ｈ2 ガス）をＴＣＤ１へ給送して出
力電圧ｖ（ｖH2＝ｖ２）を測定し、この測定した出力電
圧ｖN2，ｖH2を下記（７）式および（８）式に代入して
固有の装置定数Ａ，Ｂを求め、この求めた装置定数Ａ，
Ｂを熱伝導率算出部４における演算式中の装置定数Ａ，
Ｂとして設定している。Here, if the specific device constants A and B are known, the output voltage v is substituted into the above equation (6) to obtain
The thermal conductivity λm of the sample gas can be obtained. Therefore, in the present embodiment, the above equation (6) is set as an arithmetic expression in the thermal conductivity calculating section 4, and the unique device constants A and B in this arithmetic expression are determined as follows. That is, a first calibration gas (for example, 1) whose thermal conductivity is known
00% N 2 gas) to the TCD 1 and output voltage v (v
N2 = v1) measuring a second calibration gas thermal conductivity is known (for example, by measuring the 100% H 2 gas) feeding to TCD1 to the output voltage v (v H2 = v2), the measurement By substituting the obtained output voltages v N2 and v H2 into the following equations (7) and (8), unique device constants A and B are obtained.
B is a device constant A,
B is set.
【００１４】 Ａ＝（ｖN2 2 −ｖH2 2 ）／Ｒｈ・（λN2−λH2） ・・・（７） Ｂ＝（ｖN2 2 ・λH2−ｖH2 2 ・λN2）／Ｒｈ・（λH2−λN2） ・・・（８） なお、この式において、λN2（＝λ１）は１００％Ｎ2
ガスの（ＴRh＋ＴRR2）／２における熱伝導率（ｗ／ｋ
・ｍ）、λH2（＝λ２）は１００％Ｈ2 ガスの（ＴRh＋
ＴRR2 ）／２における熱伝導率（ｗ／ｋ・ｍ）である。
また、上記（７）式および（８）式は、Ａ・λｍ＋Ｂ＝
ｖ2 ／Ｒｈを変形して得られるｖ2 ＝Ｒｈ・Ａ・λｍ＋
Ｒｈ・ＢにｖN2，λN2およびｖH2，λH2を代入して得ら
れる下記（９）および（１０）式の連立方程式を解いて
得られるものである。 ｖN2 2 ＝Ｒｈ・Ａ・λN2＋Ｒｈ・Ｂ ・・・（９） ｖH2 2 ＝Ｒｈ・Ａ・λH2＋Ｒｈ・Ｂ ・・・（１０）A = (v N2 2 −v H2 2 ) / Rh · (λ N2 −λ H2 ) (7) B = (v N2 2 · λ H2 −v H2 2 · λ N2 ) / Rh · (Λ H2 −λ N2 ) (8) In this equation, λ N2 (= λ1) is 100% N 2
Thermal conductivity (w / k) of gas at (T Rh + T RR2 ) / 2
M), λ H2 (= λ2) is (T Rh +) of 100% H 2 gas.
T RR2 ) / 2 is the thermal conductivity (w / km ).
The above equations (7) and (8) are given by A · λm + B =
v obtained by modifying a 2 / Rh v 2 = Rh · A · λm +
The Rh · B v N2, λ N2 and v H2, following which is obtained by substituting the lambda H2 (9) and (10) is obtained by solving the simultaneous equations of expression. v N2 2 = Rh · A · λ N2 + Rh · B (9) v H2 2 = Rh · A · λ H2 + Rh · B (10)
【００１５】一方、本実施例において、ＲＯＭ６には、
試料ガスに含まれる測定対象ガスおよび共存ガスの種類
に応じ分析計全体として共通に定められる検量線が、複
数種類格納されている。すなわち、測定対象ガスをＨ2
とし共存ガスをＮ2 としたときの試料ガスの熱伝導率λ
ｍに対するＨ2 ガスの濃度を示す検量線（図２参照：Ｎ
2 −Ｈ2 検量線）や、測定対象ガスをＨ2 とし共存ガス
をＣＨ4 としたときの試料ガスの熱伝導率λｍに対する
Ｈ2 ガスの濃度を示す検量線（ＣＨ4 −Ｈ2 検量線）
や、測定対象ガスをＨ2 とし共存ガスをＣＯ2 としたと
きの試料ガスの熱伝導率λｍに対するＨ2 ガスの濃度を
示す検量線（ＣＯ2 −Ｈ2 検量線）など、多種類の検量
線が格納されている。これら、検量線は、物理データと
してすでに求められているものもあるが、求められてい
ない場合には実測のうえ作成する。On the other hand, in this embodiment, the ROM 6 has
A plurality of types of calibration curves commonly defined for the entire analyzer according to the types of the measurement target gas and the coexisting gas contained in the sample gas are stored. That is, the gas to be measured is H 2
And the thermal conductivity λ of the sample gas when the coexisting gas is N 2
calibration curve showing the concentration of H 2 gas with respect to m (see FIG. 2: N
2 -H 2 calibration curve) or, a calibration curve showing the concentration of the H 2 gas to the measuring object gas of H 2 coexisting gas to the thermal conductivity λm of the sample gas when the CH 4 (CH 4 -H 2 calibration curve )
And various types of calibration such as a calibration curve (CO 2 -H 2 calibration curve) showing the concentration of H 2 gas with respect to the thermal conductivity λm of the sample gas when the gas to be measured is H 2 and the coexisting gas is CO 2. Lines are stored. Some of these calibration curves have already been obtained as physical data, but if they have not been obtained, they are created after actual measurement.
【００１６】また、本実施例において、濃度導出部５
は、試料ガスの構成に応じ、ＲＯＭ６に格納されている
検量線の中から所要の検量線を読み出す。本実施例で
は、測定対象ガスをＨ2 とし共存ガスをＮ2 としている
ので、外部からの指定に応じ、Ｎ2 −Ｈ2 検量線を読み
出す。そして、この読み出したＮ2 −Ｈ2 検量線を参照
として、熱伝導率算出部４にて算出された試料ガスの熱
伝導率λｍに基づき、試料ガスに含まれるＨ2 ガスの濃
度を求め、この濃度を測定濃度値として出力する。In the present embodiment, the concentration deriving unit 5
Reads a required calibration curve from the calibration curves stored in the ROM 6 according to the configuration of the sample gas. In the present embodiment, since the gas to be measured is H 2 and the coexisting gas is N 2 , an N 2 -H 2 calibration curve is read according to an external designation. Then, with reference to the read N 2 -H 2 calibration curve, the concentration of H 2 gas contained in the sample gas is determined based on the thermal conductivity λm of the sample gas calculated by the thermal conductivity calculator 4, This density is output as a measured density value.
【００１７】なお、本実施例においては、測定対象ガス
を熱伝導率の高いＨ2 としたが、Ｈｅなどの高熱伝導率
のガスとしてもよい。また、これとは逆に、熱伝導率の
低いＣｌ2 などのガスを測定対象ガスとしてもよい。す
なわち、熱伝導率の変化が大きいガスであれば、Ｈ2 と
同様にしてその濃度を測定することが可能である。ま
た、本実施例では、第１の校正ガスを１００％Ｎ2 ガ
ス、第２の校正ガスを１００％Ｈ2 ガスとしたが、熱伝
導率が既知のガスであれば如何なるガスも校正ガスとな
り得る。また、本実施例では、ＲＯＭ６に多種類の検量
線を格納しておくものとしたが、これら検量線は近似式
に置き換えて格納しておくようにしてもよい。In this embodiment, the gas to be measured is H 2 having a high thermal conductivity, but it may be a gas having a high thermal conductivity such as He. Conversely, a gas such as Cl 2 having a low thermal conductivity may be used as the measurement target gas. That is, if the gas has a large change in thermal conductivity, its concentration can be measured in the same manner as H 2 . In this embodiment, the first calibration gas is 100% N 2 gas, and the second calibration gas is 100% H 2 gas. However, any gas having a known thermal conductivity can be used as the calibration gas. obtain. Further, in this embodiment, various kinds of calibration curves are stored in the ROM 6, but these calibration curves may be stored by replacing them with approximate expressions.
【００１８】[0018]
【発明の効果】以上説明したことから明らかなように本
発明によれば、試料ガスを測温抵抗体へ給送すると、こ
の測温抵抗体の温度変化が出力電圧ｖの変化として検出
され、この検出される出力電圧ｖの変化に基づいて測温
抵抗体へのエネルギーの供給量が制御され、その発熱温
度が一定値に保たれ、発熱温度が一定値に保たれた状態
での出力電圧ｖが固有の装置定数を含む所定の演算式に
代入され、試料ガスの熱伝導率が算出されるものとな
り、この算出された熱伝導率に基づき、試料ガスに含ま
れる測定対象ガスおよび共存ガスの種類に応じて定めら
れている試料ガスの熱伝導率に対する測定対象ガスの濃
度を示す検量線を参照として、測定対象ガスの濃度が導
出されるものとなり、分析計毎に固有の検量線を用いる
ことなく、測定対象ガスの濃度を測定することができ
る。この場合、固有のものとしては、熱伝導率算出手段
における演算式中の装置定数を、既知の熱伝導率λ１の
第１の校正ガスおよび既知の熱伝導率λ２の第２の校正
ガスを測温抵抗体へ給送して出力電圧ｖ１およびｖ２を
測定し、これら測定した出力電圧ｖ１，ｖ２および熱伝
導率λ１，λ２に基づいて定めてやるのみでよいので、
校正，調整に要する時間を従来のものに比して大幅に短
縮することが可能となる。As is apparent from the above description, according to the present invention, when the sample gas is supplied to the resistance temperature detector, a temperature change of the resistance temperature detector is detected as a change of the output voltage v. The amount of energy supplied to the resistance temperature detector is controlled based on the detected change in the output voltage v, and the output voltage in a state where the heat generation temperature is maintained at a constant value and the heat generation temperature is maintained at a constant value v is substituted into a predetermined arithmetic expression including a unique device constant, and the thermal conductivity of the sample gas is calculated. Based on the calculated thermal conductivity, the gas to be measured and the coexisting gas contained in the sample gas are calculated. Determined according to the type of
Concentration of the gas to be measured relative to the thermal conductivity of the sample gas
The concentration of the gas to be measured is derived with reference to the calibration curve
And use a unique calibration curve for each analyzer
Without measuring the concentration of the gas to be measured.
You. In this case, the device constants in the arithmetic expressions in the thermal conductivity calculating means are uniquely measured by measuring the first calibration gas having a known thermal conductivity λ1 and the second calibration gas having a known thermal conductivity λ2. Since the output voltages v1 and v2 are supplied to the thermal resistor and measured, and only the output voltages v1 and v2 and the thermal conductivity λ1 and λ2 need to be determined .
Calibration, and the time required for adjustment can be greatly shortened as compared with the prior art.
【図１】 本発明に係る熱伝導率式水素濃度計の要部を
示す図である。FIG. 1 is a view showing a main part of a thermal conductivity type hydrogen concentration meter according to the present invention.
【図２】 この熱伝導率式水素濃度計のＲＯＭに格納さ
れている検量線を例示する図である。FIG. 2 is a diagram illustrating a calibration curve stored in a ROM of the thermal conductivity type hydrogen concentration meter .
【図３】 従来の熱伝導率式水素濃度計の要部を示す図
である。FIG. 3 is a diagram showing a main part of a conventional thermal conductivity type hydrogen concentration meter .
１…測温抵抗体（ＴＣＤ）、Ｒ１，Ｒ２，Ｒ３…抵抗、
３…比較器、４…熱伝導率算出部、５…濃度導出部、６
…ＲＯＭ、７…恒温槽。1: Temperature measuring resistor (TCD), R1, R2, R3: resistance,
3 ... Comparator, 4 ... Thermal conductivity calculating unit, 5 ... Concentration deriving unit, 6
... ROM, 7 ... thermostat.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 27/18 G01N 25/18 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 7 , DB name) G01N 27/18 G01N 25/18
Claims (1)
抗体と、 この測温抵抗体の温度変化を出力電圧ｖの変化として検
出し、この検出される出力電圧ｖの変化に基づいて前記
測温抵抗体へのエネルギーの供給量を制御しその発熱温
度を一定値に保つ制御手段と、 この制御手段によりその発熱温度が一定値に保たれた状
態での出力電圧ｖを固有の装置定数を含む所定の演算式
に代入して前記試料ガスの熱伝導率を算出する熱伝導率
算出手段と、 この熱伝導率算出手段の算出した熱伝導率に基づき、試
料ガスに含まれる測定対象ガスおよび共存ガスの種類に
応じて定められている試料ガスの熱伝導率に対する測定
対象ガスの濃度を示す検量線を参照として測定対象ガス
の濃度を導出する濃度導出手段とを 備え、前記熱伝導率算出手段における演算式中の前記固有の装
置定数は、 既知の熱伝導率λ１の第１の校正ガスを前記
測温抵抗体へ給送して前記制御手段によりその発熱温度
が一定値に保たれた状態での出力電圧ｖ１を測定し、既
知の熱伝導率λ２（λ１≠λ２）の第２の校正ガスを前
記測温抵抗体へ給送して前記制御手段によりその発熱温
度が一定値に保たれた状態での出力電圧ｖ２を測定し、
これら測定した出力電圧ｖ１，ｖ２および前記熱伝導率
λ１，λ２に基づいて定められていることを特徴とする
熱伝導率式ガス濃度分析計。A temperature measuring resistor disposed in a sample gas supply passage; detecting a temperature change of the temperature measuring resistor as a change in an output voltage v; Control means for controlling the amount of energy supplied to the resistance temperature sensor to maintain its heat-generating temperature at a constant value; and controlling the output voltage v while the heat-generating temperature is maintained at a constant value by this control means . and the thermal conductivity calculating means for calculating the thermal conductivity of the assignment to the sample gas to a predetermined arithmetic expression including an apparatus constant, based on the calculated thermal conductivity of the thermal conductivity calculating means, trial
Gas and coexisting gas contained in the feed gas
Measurement for the thermal conductivity of the sample gas specified accordingly
Measurement target gas with reference to the calibration curve showing the concentration of the target gas
Concentration deriving means for deriving the concentration of the thermal conductivity.
The set constant is obtained by supplying a first calibration gas having a known thermal conductivity λ1 to the resistance temperature detector and measuring the output voltage v1 in a state where the heat generation temperature is maintained at a constant value by the control means. A second calibration gas having a known thermal conductivity λ2 (λ1 ≠ λ2) is supplied to the resistance temperature detector, and the output voltage v2 in a state where the heat generation temperature is maintained at a constant value by the control means is reduced. Measure,
Output voltage v1 that these measurements, v2 and the thermal conductivity .lambda.1, characterized in that are constant because on the basis of λ2
Thermal conductivity gas concentration analyzer .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06066528A JP3114137B2 (en) | 1994-03-11 | 1994-03-11 | Thermal conductivity gas concentration analyzer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06066528A JP3114137B2 (en) | 1994-03-11 | 1994-03-11 | Thermal conductivity gas concentration analyzer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07248304A JPH07248304A (en) | 1995-09-26 |
| JP3114137B2 true JP3114137B2 (en) | 2000-12-04 |
Family
ID=13318472
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06066528A Expired - Lifetime JP3114137B2 (en) | 1994-03-11 | 1994-03-11 | Thermal conductivity gas concentration analyzer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3114137B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0646494U (en) * | 1992-12-03 | 1994-06-28 | 弘 月見里 | Steam boiling pot |
| JP2007248220A (en) * | 2006-03-15 | 2007-09-27 | Yamatake Corp | Heat conductivity measuring method, its measuring instrument, and gas component ratio measuring instrument |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018100608A1 (en) * | 2016-11-29 | 2018-06-07 | 英弘精機株式会社 | Thermal conductivity measurement device, thermal conductivity measurement method, and vacuum evaluation device |
| EP3521816A1 (en) * | 2018-02-06 | 2019-08-07 | L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Method for in-situ monitoring of the quality of gas delivered to a consuming industrial site using the thermal conductivity technique |
| JP7127580B2 (en) * | 2019-02-28 | 2022-08-30 | オムロン株式会社 | Oxygen concentration measuring device and oxygen concentration measuring method |
| CN113866070A (en) * | 2021-11-19 | 2021-12-31 | 郑州大学 | Device and method for measuring micro surface area of macroporous material |
-
1994
- 1994-03-11 JP JP06066528A patent/JP3114137B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0646494U (en) * | 1992-12-03 | 1994-06-28 | 弘 月見里 | Steam boiling pot |
| JP2007248220A (en) * | 2006-03-15 | 2007-09-27 | Yamatake Corp | Heat conductivity measuring method, its measuring instrument, and gas component ratio measuring instrument |
| JP4505842B2 (en) * | 2006-03-15 | 2010-07-21 | 株式会社山武 | Thermal conductivity measuring method and apparatus, and gas component ratio measuring apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07248304A (en) | 1995-09-26 |
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