Unique Scott Technology
Air Liquide's commitment to continuous innovation in specialty gas technology has resulted in an impressive portfolio of mixing, blending and analysis capabilities. These technical innovations, coupled with 100 years of experience in the business, allow us to achieve unequalled product specifications, regardless of the nature of the components in the specialty gas mixture. Certain technologies and product attributes are only available from Air Liquide.
Guaranteed Mixture Stability Begins with ACULIFE™
Scott brand ACULIFE is a suite of proprietary cylinder inerting treatments, utilized
to enhance the stability of reactive gas and liquid mixtures.
These chemical vapor deposition processes eliminate gas-to-cylinder surface interactions to provide guaranteed stability for ppm and sub-ppm calibration standards, making possible a variety of unique and innovative products. For example, Air Liquide is the leading supplier of hydrogen sulfide in air mixtures, with guaranteed stability for safety and industrial hygiene applications. We also have unique hydrogen chloride gas standards in the low ppm range, made possible by ACULIFE.
Scott Brand ACUBLEND™ Produces Zero Blend Tolerance
ACUBLEND can produce a gas mixture having a unique feature called Zero Blend Tolerance. Zero blend tolerance means no difference between certified and requested concentration. The process is also capable of preparing a gas mixture precisely within a specified blend tolerance. Click here to learn more about ACUBLEND and its benefits.
Scott Brand MICROGRAV™ Enables PPT Concentrations
Air Liquide is the only specialty gas manufacturer to prepare and certify accurate
and stable gas mixtures containing compounds with concentrations approaching
parts-per-trillion (ppt) levels in returnable and nonreturnable cylinders.
Our MICROGRAV process is a direct blending technique that eliminates inaccuracies inherent in serial dilution methods. Analytical quality control with proven gas chromatographic techniques verifies the accuracy of MICROGRAV mixtures. ACULIFE inerting cylinder treatment provides one year guaranteed stability for mixtures in a nitrogen balance gas. Air Liquide is the primary supplier of MICROGRAV gas mixtures to NIST and the EPA, as well as to state and other government agencies.
Click here to get more information about available MICROGRAV mixtures.
UNIPHASE™ Liquid Mixtures
Many applications require mixtures containing low vapor pressure and liquid components. These may be components that are in the liquid phase at normal atmospheric temperatures and pressures, or they may be components that are in the liquid state at the concentration and pressure desired in the container. Liquid mixtures can be prepared two ways. In the first, the blend is made in a conventional cylinder in which the components exist in the cylinder under their own vapor pressures. In this type of mixture a dip tube, allowing withdrawal from the bottom of the container, is usually provided. The withdrawal of the liquid phase minimizes the concentration changes that will occur during emptying of the cylinder due to fractionation of the more volatile components.
In the second method, the mixture is made completely in the liquid phase using a floating piston cylinder to preserve mixture integrity. Such mixtures are called UNIPHASE. UNIPHASE liquid mixtures are highly recommended when mixture components possess significantly different vapor pressures and solubility characteristics. Air Liquide provides a Certificate of Accuracy with detailed BTU calculations for all UNIPHASE mixtures. Phase envelopes are available upon request. Air Liquide representatives will advise you when UNIPHASE piston cylinders are necessary to ensure a single phase mixture.
Click here to learn more about Scott liquid mixtures.
Scott Brand GRAVSTAT™ Gravimetric Blending
Gas mixtures that are prepared gravimetrically are produced by weighing the gas components on a high-load, high-sensitivity analytical balance. Air Liquide uses NIST or VSL weights for this procedure to assure mixtures are traceable to a reference standard that is certified by a national or international metrology organization. Our gravimetric process, GRAVSTAT™, takes into account all statistical parameters including scale weight uncertainty, scale calibration and the raw material impurities of all pure components in multi-component mixtures. As a result of GRAVSTAT, Air Liquide can assert the process accuracy by calculating gravimetric uncertainty and properly representing the true value of component concentration.