Specialty Gas Products Specifications | Certified Gas
MESA Specialty Gases offers three types of specialty gas product specifications available for your calibration gas standard: Primary, Certified, and Gravimetric Standards.
The Primary Standard is the most accurate and is made by weight. Unless stated otherwise, the specialty gas mixture is certified to ± 1% analytical accuracy of the numbers reported.
The Certified Standard is made by a combination of pressure and/or weight measurements. Unless stated otherwise, the calibration gas mixture is certified to ± 2% analytical accuracy of the numbers reported.
In the case of all specialty gas product specifications, final calibration gas mixtures are analyzed by gas chromatography or other suitable analytical methodology to confirm they are within the allowed tolerances. All calibration gas mixtures are supplied with a "Certificate of Analysis" that details the requested and analytical values as well as preparative and analytical methods used by MESA Specialty Gases to prepare the calibration gas standard.
| STANDARD SPECIFICATIONS FOR CALIBRATION GAS, SPECIALTY GAS, NATURAL GAS, PETROCHEMICAL AND REFINERY GAS STANDARDS | |||
| Product Grade | Blend Tolerance | Blend Tolerance (1) | Certification Accuracy (1) |
|---|---|---|---|
| Primary | Below 5 ppm (2) | ±10 to 15% | ±1 to 2% |
| 5-100 ppm | ±5% | ±1% | |
| 101-5000 ppm | ±5% | ±1% | |
| Above 0.5% | ±2% | ±1% | |
| Certified | Below 5 ppm (2) | ±15-20% | ±2-5% |
| 5-100 ppm | ±10% | ±2% | |
| 101-5000 ppm | ±10% | ±2% | |
| Above 0.5% | ±5% | ±2% | |
| Gravimetric (3) | 0-100 ppm | ±20% | Non-Certified by independent laboratory analysis. Concentration Ranges are reported based on the gravimetric values. |
| 101-5000 ppm | ±10% | ||
| Above 0.5% | ±5% | ||
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The Blend Tolerance is expressed as the relative percentage deviation from the requested concentration of the individual components. Blend Tolerances of multi-component mixtures might vary as a function of the requested individual component concentrations and complexity of the mixture. Certification Accuracy is shown as a percentage of the reported value.
The Certification Accuracy of a Primary Standard is as follows:
±1% relative for concentrations ≤2.00%
±0.02% absolute for concentrations >2.00% for standards with ≤15 components
(excluding the reported value of the balance gas or liquid)
±1% relative for concentrations >2.00% for standards with >15 components - Tolerance of minor components below 5 ppm may vary depending on the component and complexity of the mixture.
- Each component is reported at the requested concentration ± the % stated for the concentration range.