The gas mixtures are made to any concentration within the permissible limits of Physics and Chemistry. Which are non-explosive, non-reactive, stable mixture of gases in wide range of packaging.Gravimetric filling uses ultra-high precision balances, calibrated & traceable NPL body periodically to weigh each component into the cylinder. This ensures that the expected tolerance requirements are always fulfilled.To achieve minimum blend tolerance and to minimize uncertainity we use :High purity raw materials through Linde A.G. Technology Plant . Properly prepared cylinders with good internal surfaceSophisticated Equipments to handle ppb level mixturesRight blending methodsAccurate Instruments and Accurate StandardsOur calibration mixtures are prepared and certified to meet the most stringent metrological standards. Precise manufacturing of calibration gas mixtures involves many critical steps:Raw material purityImpurity characterizationCalculation of phase behavior for the calibration gas mixtureCylinder PreparationPrecise blendingIndependent confirming analysis of the final calibration gas mixtureTraceabilityRaw Material Analysis:Raw Materials are pre- analysed to ensure that the final outcome of the gas mixture meets your specification for purity, accuracy and stability. Balance gases for mixtures are 99.999% (N5.0) or higher where appropriate.Cylindrical Preparation:Cylinder selection will take into consideration the chemical and physical properties of the gas mixture. For reactive mixtures we will use specially prepared cylinders and fitted with stainless steel valves in order to guarantee the stability of your gas mixture. To further minimise any chance for cross-contamination, cylinders are only recycled for use with gas mixtures within the same group classification.Production & Analysis:Mixture purity and composition is verified by analysis and certification following a thorough homogenisation process. To ensure that more complex and reactive mixtures have been reliably achieved, these mixtures will be analysed several times over a period of days/weeks, as appropriate, in order to guarantee their final stability and quality.Traceability:Our analytical operations are traceable through a calibration standard produced to either a recognized international standard such as NIST or NPL or a gravimetrically manufactured Primary Reference Standard traceable to NPL standard masses.