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Proficiency Testing

Proficiency testing analyzed against NIST-traceable standards

Proficiency Testing services from Air Liquide help you to assess the accuracy of your laboratory analysis by comparing it with other laboratories participating in the service.

This allows a higher degree of confidence in both your laboratory analysis and the identification of potential problems in analyses accuracy. Participants in the program are anonymous and all results are confidential. Gas mixtures used during the program can be retained as master gas calibration standards.

Air Liquide’s Proficiency Testing services improve the credibility of your analytical laboratory capabilities and provide critical selection criteria when evaluating and selecting third-party analytical services.

Comprehensive laboratory analysis

Air Liquide’s Proficiency Testing services allow customers to test for the following:

  • Oxygen in nitrogen
  • Sulfur dioxide emissions in air
  • Zero gas: trace nitrogen oxide, sulfur dioxide and carbon dioxide in nitrogen
  • Hydrogen sulfide in nitrogen
  • BTU/natural gas standard: C1-C6
  • Ethylene (polymer grade): Hydrogen sulfide and ammonia in ethylene
  • Propylene (polymer grade): Hydrogen sulfide and ammonia in propene
  • BTU/natural gas: C1-C9
  • LNG composition: C1-C6
  • Propane composition: Trace hydrocarbons in propene
  • Reduced sulfurs: Hydrogen sulfide, carbonyl sulfide and carbon disulfide in nitrogen
  • Reduced sulfurs (methane): Hydrogen sulfide, carbonyl sulfide and carbon disulfide in methane
  • Carbon dioxide: Carbonyl sulfide and hydrocarbons in carbon dioxide
  • Diesel exhaust/turbine exhaust: carbon dioxide, carbon monoxide, oxygen and propane in nitrogen
  • High nitric oxide and nitrogen oxide in nitrogen
  • Low nitric oxide and nitrogen oxide in nitrogen
  • Constant volume sampling: carbon dioxide, carbon monoxide and propane in air

An analysis benchmark for Proficiency Testing

Air Liquide uses its ACUBLEND™ and GRAVSTAT™ proprietary blending processes to produce a homogeneous batch of gas cylinders. After they are analyzed against NIST-traceable standards, Air Liquide sends participants a cylinder containing the mixture they wish to test. With no prior knowledge of the gas concentrations contained in the cylinder, participants analyze its contents.

Upon completing the analysis, participants report their findings to Air Liquide confidentially. Air Liquide then compiles a report summarizing the analytical results of each participant. Results are shown by participant ID number to protect anonymity. The report details mean and median concentrations, method of analysis and statistical data, such as variance mean, standard deviation and coefficient of variations. Participants then have the option to keep the gas mixture for use as a high-confidence calibration gas standard.

Cylinders are shipped quarterly, semi-annually or annually, depending on the program.