Oxygen AnalyzersMeasurement Principles/Model Selection/Maintenance Sites

Measurement Principles/Model Selection/Maintenance Sites

Measurement principles of zirconia oxygen analyzers

When zirconia ceramics which have undergone electrode machining on both sides are placed at high temperature, oxygen molecules on the electrode section of one side ionize, while oxygen molecules on the other electrode section are converted back into oxygen molecules. This property is called the ion conduction. The amount of the ion conduction increases as the difference in the oxygen concentration on the two sides of the zirconia ceramic increases. Electrons are passed between the two electrodes, and the amount of the ion conductance (that is, the difference in the oxygen concentration on the two sides of the zirconia ceramics) can be measured as the electromotive force between the two electrodes. As the following figure shows, this electromotive force produces a stable figure in accordance with the Nernst equation, so Toray’s zirconia sensors can measure oxygen concentration values reliably and stably.

General notes on use of zirconia oxygen analyzers

Zirconia oxygen analyzers operate at high temperatures of roughly 700°C. Therefore, please be aware that the following situations may make measurement impossible or adversely affect sensor service life.
  • Oxygen analyzers cannot be used in explosion-proof zones because they contain electrical furnaces.
  • If flammable gas (e.g. hydrogen, methane, alcohol, or carbon monoxide) enters the oxygen analyzer, it will cause a combustion reaction and result in measurement error.
  • Organic silica (used for sealants, etc.) will cause sensor degradation. (This is one of the extremely common cause of sensor degradation.)
  • Halogens (especially chlorine) cause sensor failures.
  • If substances with high calorific value such as carbon monoxide intermittently enter the oxygen analyzer, the sensor will accumulate a heat history, and this will cause sensor malfunction.
  • If large amounts of corrosive gasses such as NOX or SOX enter the oxygen analyzer, they will cause sensor malfunction.
  • At high temperatures, Freon gas may cause a separation reaction, resulting in sensor degradation.
  • Water droplets, dust and mist will damage the sensor, shorten its service life, and cause errors. When measuring gasses containing them, remove them before supplying the gas into the oxygen analyzer. Please consult with us regarding removal methods before purchasing an oxygen analyzer.

Model selection chart

Please use the chart below to help you choose the appropriate model.

Applications Model Description Other options
and electronic components
MS-500 For mounting on systems such as semiconductor manufacturing equipment; up to 8 measurement points  
LC-450A Capable of measurement in ppm; AC powered
  • Activated carbon filter
  • Si filter
  • Cotton filter
LC-450D Capable of measurement in ppm; DC powered
LC-860 Capable of measurement in ppb; AC powered
SD/LD-450 With vacuum chamber (for installation in systems) AC power unit: DU-450
Baking furnaces,
N2 reflow ovens,
and dirty gas
RF-400 Baking furnaces with oxygen sensor protection; exclusively for reflow oven
  • Activated carbon filter
  • Si filter
  • Cotton filter
LC-750H/PC-111 For high and medium concentration dirty gas, built-in gas suction pump
Gas plant, air separation LC-750H General type for high and medium concentrations
LC-750H/PC-110 For clean gas of high and medium concentrations; built-in gas suction pump
LC-750L General type for low concentrations
LC-750L/PC-120 For low-concentration clean gas, built-in gas suction pump
Vacuum deposition,
sealed furnaces,
and gloveboxes
SD/LD-450 Separate sensor and converter; thin, wall-mount converter AC power unit:DU-450
Food packaging LC-450F For sampling after gas filling (sampling probe)
  • Activated carbon inlet
  • Head space sampler
LC-750F For sampling after gas filling (syringe)
LF-200 For installation in gas filling automatic packing machine
  • Activated carbon filter
  • Cotton filter

Oxygen analyzer maintenance sites

The following sites in Japan and abroad provide maintenance services for Toray oxygen analyzers.

  • Japan
    Toray Engineering D Solutions Co., Ltd. TEL:+81 -77-544-1621
    1-45, Oe 1-chome, Otsu, Shiga 520-2141, JAPAN
  • Korea
    PnK system Inc. TEL:+82-31-376-8531
    #708, 878, Dongtansunhwan-daero, Hwaseong-si, Gyeonggi-do, 18469, Republic of Korea
  • China
    Toray Engineering (Shanghai) Co., Ltd. TEL:+ 86-21-5241-7700
    Room01 36th Floor,Zhao Feng Plaza, 1027 Chang Ning Road Chang Ning Area, Shanghai 200050, China
  • Taiwan
    Thales System Co.,Ltd. TEL:+886-3-657-2270
    1F.,No.81,S.Sec.,Xianzheng 2nd Rd., Zhubei City,Hsinchu County 302,Taiwan (R.O.C.)

    Environmental Technology Company TEL:+886-7-312-2698
    16F.,No.255-2,Jiouru 2nd Rd.,Sanmin Dist.,Kaohsiung City 807,Taiwan

    EQP Series Co.,Ltd. TEL:+886-2-2601-3667
    No.3 Lane 6 Ren-ai Rd Sec.2 Linkou Township,Taipei County 224, Taiwan
  • Philippines
    RCLL Trading Corp. TEL+63-2-533-5565
    No.28 San Roque Street, Mandaluyong City, Philippines
  • Thailand
    Citigas Co., Ltd. TEL:+66-2-920-8990
    189/194 Moo. 5 Soi Liabklongbangpai, Junthongeiam Rd., T. Bangrakpattana
    A. Bangbuathong, Nonthaburi 11110, Thailand
  • India
    S.V. SCIENTIFIC TEL+91-80-2356-7255
    No. 23/A, 2nd Floor, Serpentine Road, Kumara Park West,Bangalore 560-020, India
  • Indonesia
    PT.REXINDO OTOTEKNIK TEL+62-21-8273-5509
    Jl. Jambu 4, No.65 A RT. 02/08, Kel. Jatimulya Kec. Tambun Selatan Bekasi 17510
  • U.S.A.
    RKI Instruments Inc. TEL:+1-510-441-5656
    33248 Central Avenue Union City, CA USA
  • U.K.
    Weatherall Equipment & Instruments Ltd TEL +44 (0)1296 622 180 Unit 1 Station Approach Wendover Bucks. HP22 6BN England

Maintenance site information

Maintenance site information


  • East Japan : +81-3-5962-9775

    West Japan : +81-77-544-6224