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Continuous Emissions Monitoring

Air Products has been a leading gas supplier to the air emissions monitoring market for decades. Our products can be used for continuous emissions monitoring including all stages of testing as defined in EN14181.

Calibration of a continuous emissions monitoring system (CEM) necessitates traceable and accurately certified gas mixtures. The Experis® specialty gases range fulfils this requirement and delivers further benefits for users undertaking quality assurance levels QAL1, QAL2 or QAL3.

Air Products is currently the only supplier of speciality gases able to supply calibration gas mixtures certified within an ISO 17025 accreditation scope that contain NO, SO₂, CO and CO₂ in the same cylinder. This enables users to take advantage of a number of key technical, safety and cost benefits when compared to the more commonly available binary gas mixtures.

Complementing these mixtures is a range of ultra high purity gases which can be used for operating analytical instrumentation or as zero gases.

Unique Features of Air Products' Gas Mixtures

There are many reasons why the Air Products' range of process, calibration and accredited mixtures are used by the air emissions market, these include:

Unrivalled Stability

Achieved by using Experis® cylinder treatments, and endorsed by some of the world's leading metrology institutes

Highly Accurate Mixtures

Measurement uncertainties calculated for each individual component


On line, 24/7 access to you gas cylinder inventory and certification via the MyAirProducts℠ portal

Unique ISO 17025 Accreditation Scope

Including multi-component mixtures with CO, CO₂, NO and SO₂ in the same cylinder

Comprehensive Cylinder Size Options

Mixtures supplied in a wide range of options to suit the application

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Available to existing customers via MyAirProducts℠

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“What is an accredited gas mixture?”
Accredited gas mixture is a commonly used term to describe a gas mixture that has been certified within an ISO 17025 accreditation scope.

ISO 17025 defines the general requirements for the competence of testing and calibration for laboratories. Accreditation is normally awarded by nation accreditation bodies, such as UKAS, ENAC and DKD.

The use of accredited gas mixtures is mandated for some aspects of quality assurance defined in EN14181:Quality Assurance of automated measuring systems.