Page 94 - Praxair - Specialty Gases and Equipment Reference Guide

Behind The Scenes

Safe, Accurate, Consistent, Reliable... Every Time
Sophisticated communication programs and ■ Reference Materials
mixture blending software (worldwide databases – Standard Reference Materials (SRM)
with international access) provide the very latest – NIST Traceable Reference Materials (NTRM)
in mixture technology for our customers. – Gas Manufacturer’s Intermediate Standards (GMIS)
– Praxair Primary Laboratory Standards (PPLS)
■ Component Raw Material
All blending source gases and liquids are qualified to ■ Ongoing Inter-Laboratory Quality Assurance
ensure that they are appropriate for your application. Evaluation Programs
We have determined through experience that certain – Performed Quarterly
impurities affect the performance or stability of the final
mixture. Praxair’s North American Specialty Gas Facilities are
We have developed and used special proprietary staffed with chemists and engineers trained in the
purification techniques for the removal of critical preparation and analytical certification of specialty
impurities. Upon request a complete impurity profile gas mixtures.
or specific impurity analyses can be provided. A knowledgeable sales and technical support team

■ Cylinder Preparation is ready to assist you in determining and specifying
Praxair utilizes a series of computer controlled heating, all your specialty gas needs including: high purity
vacuum and purge cycles to prepare both aluminum and gases, calibration mixtures and the correct delivery
steel cylinders. equipment.
For low concentration or highly reactive components Manufacturing And Quality Control
we use our additional, proprietary cylinder treatment Producing quality gas mixtures begins with proper cylinder
processes. With the application of these unique cylinder selection and preparation to ensure high quality and
preparation processes, we are able to produce accurate enhanced stability. Outlets are selected according to
part per billion and low part per million concentration Compressed Gas Association (CGA) guidelines.
reactive gas mixtures with guaranteed stabilities.
The manufacture and certification of all Praxair specialty
■ Blending Systems gases are documented in a comprehensive quality
Praxair prepares mixtures utilizing high load, high assurance manual. Where appropriate, traceability will
sensitivity Gravimetric Balances, Micro Balance Capillary be established to Praxair Primary Laboratory Standards or
Injection, Computerized Dynamic Blending Systems and to NIST Traceable Standards. All processes, procedures,
Volumetric Manifolds. In every case we use the method analytical methods and reports are carefully documented,
best suited to your application. controlled and internally assessed by Praxair Q.C./Q.A.
All gravimetric balances are calibrated with NIST Officers.
traceable weights. All balances, gauges and process
instruments undergo specified periodic maintenance Documentation
and calibration.
Certification:
■ Mixture Homogenization
Once a particular mixture is prepared, mechanical rolling, Certificate of Compliance (COC1)
Document that delineates that a product meets or
gas turbulence or molecular agitation is used to ensure exceeds the minimum purity or analytical accuracy
the homogeneity of the final mixture.
as specified.
■ Analytical Instrumentation Certificate of Conformance (COC2)
– Gas Chromatography (GC detectors,- Statement of guarantee that the product from a specific
TCD, FID, ECD, HID, DID, FPD, PID, NPD, RGA) batch conforms to the components, minimum purity and
– Chemiluminescence maximum impurity specifications as listed. Section C – Mixtures
– Fourier Transform Infrared (FTIR)
– Atomic Absorption (GFAA) Certificate of Analysis (COA)
A document that reports the actual analytical test results
– Mass Spectroscopy (MS) for pure product or for a calibration mixture. Either single
– Fluorescence UV cylinder or batch analysis certification is available.
– Process Instrumentation
(NDIR, O 2 , THC, H 2 O) Available Upon Request

1-877-PRAXAIR www.praxairdirect.com C•93