Linde specialty gases production and laboratory facilities perform professional and skilful 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. Please check with your local Linde office to find out what is applicable for the products you order.
The following infomation 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 components & 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.