Garantie de traçabilité de nos gaz

Mesure de la performance

La traçabilité est devenue un enjeu essentiel de l'entreprise. De nombreuses industries ont besoin de traçabilité pour pouvoir informer leurs clients de la performance des instruments et matériels qui leur sont fournis.

Dans le cadre du contrôle des émissions rejetées dans l'environnement ou de l'échange de quotas d'émissions, les autorités réclament une traçabilité pour aider à garantir le respect des exigences de sécurité publique.

La traçabilité est la relation entre une valeur mesurée et un élément établi d'un système de mesure international ou national. Elle ne peut pas être obtenue grâce au suivi d'une procédure en particulier ni à l'utilisation d'équipement spécial.

Pour que la traçabilité existe il doit y avoir une chaîne ininterrompue de comparaisons entre l'échantillon et le système de mesure accrédité. Le système de mesure à travers lequel les valeurs sont transférées doit être clairement compris et sous contrôle.

L'accréditation est un aspect important de la production de gaz spéciaux.

Plusieurs de nos unités de fabrication de gaz spéciaux HiQ® ont obtenu la certification ISO 9001 pour la production, et parmi elles certaines unités sélectionnées indépendamment ont été accréditées comme laboratoires de test et/ou de calibration, selon des normes comme l'ISO 17025-2005 et le Guide ISO 34.

Ces performances permettent à Linde de se porter garant du plus haut niveau d'assurance qualité, et d'affirmer avec certitude que les méthodes utilisées pour certifier leurs mélanges de gaz d'étalonnage accrédités sont rigoureuses, homogènes, documentées et validées.

Accreditation Certification

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Accreditation

Accreditation is an independent assessment of the competence of a laboratory to produce and/or certify samples or products. Manufacturers all over the world want to be assured that suppliers can deliver their products to the required quality. That is why accreditation is an important aspect in the production of specialty gases. Many of our HiQ® specialty gas facilities have received certification as a producer under ISO 9001 standards and follow additional programmes, such as:

• ISO 6141 (requirement for certificates for calibration gas mixtures)
• ISO 6142 (preparation of calibration gas mixtures by gravimetric method)
• ISO 6143 (comparison methods for determining and checking the composition of calibration gas mixtures)
• ISO 6144 (preparation of calibration gas mixtures by volumetric method)
• ISO 6976 (specified method for the calculation of the calorific value and the Wobbe index of dry natural gas and other combustible gaseous fuels)

In addition, dedicated Linde specialty gas facilities have received further accreditation to the highest possible standards.

Accreditation - ISO 17025:2005 Testing and/or calibrating laboratory

ISO 17025:2005 specifies the general requirements for the competence to carry out tests and/or calibration, including sampling. It covers testing and calibration performed using standard methods, non-standard methods, and laboratory-developed methods. It is applicable to all organizations performing tests and/or calibration.

These include, for example, first-, second- and third-party laboratories, and laboratories where testing and/or calibration forms part of inspection and product certification.

Accreditation - ISO Guide 34: 2000 Competence of reference material producers.

Linde Specialty gas facilities in the United Kingdom, Germany, Czech Republic, Australia and Thailand have received accreditation to ISO Guide 34. ISO Guide 34 provides the highest level of quality assurance and allows Linde to confidently state that the methods used to certify their certified reference standards are accurate, consistent, documented and validated.

ISO Guide 34 defines reference materials as substances with a precise composition traceable to the International System of Units (SI) using accurate measurements.

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Certification

Linde specialty gases production and laboratory facilities perform professional and skillful quality control and analysis of gas mixtures. It is of vital importance that the results are correct. It is also important that all the information on the analysis certificate is correct and easy to understand.

Linde always follows the latest update of the ISO 6141 standard, specifying the information on an analysis certificate. The analysis certificate from Linde is in accordance with this standard. The information is easy to locate and understand. The headings are in the appropriate language and in English, allowing the certificate to be used both in the relevant country and across borders.

All gas products are quality controlled. Where applicable, an analysis certificate is included in the product. If not included, it can be requested separately.

The following information can be found on the analysis certificate:

1. The date when the certificate was written, the beginning of the shelf life.
2. Identification of the analysis certificate.
3. Table of componets & concentrations:
   • the unit can be given either in mole, volume or weight
   • the uncertainty refers to the analysis of each component and is relative
   • if an absolute uncertainty is given, this appears in the column ‘Analysis result’ (for instance 202 ± 4ppm).
4. Confidence level is the probability of the analysis result falling between the uncertainty limits.
5. The blend tolerance of a gas mixture specifies how close to the ordered concentration the final concentration must fall.
6. Shelf life: In a correctly handled cylinder, the component concentrations will remain within the limits stated in the analysis result during the stated shelf life.
7. Following the temperature recommendation improves safety and helps to keep the gas mixture homogeneous.
8. The component concentrations will remain within the limits stated in the analysis result down to the recommended minimum pressure of use.