Technical Support

Technical Documentation

Oxygen Concentration Calculator

FAQs

For pre-sale technical support or technical questions please contact Oxigraf at sales@oxigraf.com or call 650.237.0155

For direct customer support and help with technical issues please contact Oxigraf at support@oxigraf.com or call 650. 237.0155

Technical Documentation

Please PDF logo click here for information on the Properties of Oxygen [PDF 64KB]
PleasePDF logo  click here for ODM -Minimum Values of O2 Concentration [PDF 44KB]
Please PDF logo click here for the Predictive Filter Setup [PDF 9KB]
Please PDF logo click here for Oxigraf Oxygen Analyzer Applications: Electrical Interface for OEM Sensors [PDF 40KB]

Oxygen Concentration Calculator

  • Calculate the volume (Vr m3) of the confined space.
  • Calculate the volume of the released gas (Vg) by multiplying the volume of the liquid nitrogen (in liters) or weight of solid carbon dioxide (in Kg) by the expansion ratio of LN (.682) or the inverse density of CO2 (.552 m3/Kg).
  • Calculate the volume of available oxygen (Vo m3) as 0.2095*(Vr-Vg).
  • Calculate the % oxygen available to breathe as 100*Vo/Vr.
  • Oxygen Concentration Calculator
    Room Length (meters)
    Room Width (meters)
    Room Height (meters)
    Type of Spill (LN or CO2)
    Amount of Spill (liters of LN2 or Kg of CO2)

    Volume of Room.
    Volume of Released Gas.
    Volume of Available Oxygen.
    Percent Oxygen Available to Breathe.

    Assumptions:

  • Uniform mixing of LN or CO2 with room air.
  • No pressure considerations taken.
  • Spill is contained in the room.



  • O2 Analyzer and Sensor Information
    Model O2 Oxygen Analyzer Info Model O2T for Refilling/Transfill Info Model O2L Hi Resolution Analyzer Info X2003/X2004 Sensor Info
    Model O2 Calibration
    [PDF 59KB]
    Model O2T Calibration
    [PDF 25KB]
    Model O2L Calibration
    [PDF 22KB]
    X2004 Mechanical Layout Drawing
    [PDF 61KB]
    Model O2 Error Messages
    [PDF 12KB]
    Model O2T Warning & Alarm Messages
    [PDF 10KB]
    Model O2L Display Messages
    [PDF 10KB]
    X2000 Electrical Connections
    [PDF 13KB]
    Model O2 Quick Reference Guide
    [PDF 13KB]
    Model O2T Quick Reference Guide
    [PDF 14KB]
    Model O2L Back Panel Interface
    [PDF 69KB]
    Analog Application Notes
    [PDF 3KB]
    Model O2 Troubleshooting Guide
    [PDF 16KB]
    Model O2T Troubleshooting Guide
    [PDF 16KB]
    Model O2L Troubleshooting Guide
    [PDF 16KB]
    X1000-X2000 Interface Schematic
    [PDF 13KB]

    FAQs

    The following information will apply to the X2003, X2004, X2007, X2008 and X2014 with exceptions noted.

    • Can we use nitrogen (in other words, 0% O2) to calibrate our Oxigraf X2004 sensor at the low calibration point?
    • What is the span calibration cycle? Could you give me some explanations about span calibration?
    • Would it be possible to have the X2004 loaded with a right-angled interface connector along the lines of Molex 70247 which is rated at 3A?
    • What is the noise requirement of the power supply?
    • What about communication with the X2004, do you have any sample code to get us started?
    • Do you have any suggestions as to correct grounding for the X2004?
    • What about connecting to the analog outputs for the X2004?

    Q) Can we use nitrogen (in other words, 0% O2) to calibrate our Oxigraf X2004 sensor at the low calibration point?
    A) You must calibrate the X2000 series with a gas mixture that contains at least 2% O2. Some absorption is necessary in order for the sensor line lock servo to maintain lock. The X2008 in high resolution, low range mode (0-10%) can utilize pure N2 for its low calibration reference gas.

    Q) What is the span calibration cycle? Could you give me some explanations about span calibration?
    A) The span cal cycle consists of a high point calibration preceded by adjustment of theanalog absorption gain for full scale input to the A/D converter. Span cal is useful if you intend to restrict the O2 measurement range to some value less than 100%. For example, if you will never measure more than 50% O2, then a span cal at 50% O2 will increase the gain of the absorption channel for additional resolution. The gain increase is limited to about double the nominal gain at 100%. There is not much improvement in the O2 noise because the noise amplitude is much larger that the converter LSB, even at low gain.

    Q) Would it be possible to have the X2004 loaded with a right-angled interface connector along the lines of Molex 70247 which is rated at 3A?
    A) Our PCB layout would accept a right angle connector in place of the straight connector now installed. One side effect of this change is that the pin numbering for the interface is reversed because of the way the right angle pins are bent. If you are using a keyed connector then it would have to be rewired to properly mate with the right angle header. If the connector is unkeyed then you can just plug it in reversed. Note that installation of the right angle header is a rework task that will result in a charge by Oxigraf.

    Q) What is the noise requirement of the power supply?
    A) The X2000 sensors will operate with power supply ripple up to the following limits,
    which are typical for switching power supplies:

    • +12 Volt Supply: 11.4 to 15.8 volts, <200 mV ripple
    • +5 Volt Supply: +4.5 to +5.25 volts, <150 mV ripple

    Q) What about communication with the X2004, do you have any sample code to get us started?
    A) Oxigraf would be more than happy to provide sample C software for X2000 customers. Feel free to contact us at:

    • Oxigraf, Inc.
    • 238 East Caribbean Drive
    • Sunnyvale, CA 94089
    • Telephone: 1-650-237-0155
    • Email: support@oxigraf.com

    Q) Do you have any suggestions as to correct grounding for the X2004?
    A) The user interface connector is a standard 0.100 in centers, 16 pin header (3M 2516-6002UB or equivalent). The recommended mating connector is the Molex 22-55-3161 housing loaded with 16-02-0104 crimp terminals for #22 wire. It is recommended that all ground pins (2, 4, and 5) be used for power supply grounding.

    Q) What about connecting to the analog outputs for the X2004?
    A) Note that the analog output voltage is referenced to the system ground at the interface connector. High ground currents in the interface wiring due to the cell heater and thermoelectric cooler will cause an error in the analog voltage if it is not measured relative to the analog ground (interface pin 9). A differential amplifier connected to the analog output (pin 10) and analog ground (pin 9) should be used to reject the common mode offset due to ground current.

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