Calibration Gas for Gas Detectors
Quality Assurance of Calibration Gas for Gas Detectors
Our calibration gas mixtures for filling disposable pressure vessels are produced gravimetrically (by weight) using sensitive modern balances capable of weighing the relatively heavy cylinders to accuracies of ±0.1 gm. This equipment allows direct measurement of cylinder content during filling and eliminates potential errors associated with indirect, manometric (pressure bases) mixing techniques. Which are subject to inaccuracies due to temperature gas compressibility’s and non-ideal behavior.
The weights used to calibrate the balances are all traceable to national physical laboratory (NPL) and NIST standards which ensures standard gas mixtures are of the highest possible accuracy. High purity precursor gases are used to ensure gravimetric filling calculations hold true.
The certification accuracy of gravimetric mixtures is dependent on the concentration levels of particular components and on molecular weights. Typically, the accuracy for a given concentration is:
|5 to 10 ppm||Depends on components (typically ±10%)|
|10 ppm to 50 ppm||±5%|
|50 ppm to 1%||±2%|
|1% to 10%||±2%|
|10% to 50%||±2%|
Our non-refillable products are labeled with the nominal concentration requested by customers. We do not use the exact values from the production process. Thus, there is a tolerance which must be applied to this figure, which is typically:
|10 ppm to 50 ppm||±20%|
|51 ppm to 1%||±10%|
|1% to 10%||±10%|
|10% to 50%||±5%|
Where analytical work is required to certify minor components, the accuracy is plus or minus ±2%.
Our non-refillable pressure vessels are filled and supplied in accordance with out ISO 9001 procedures. All incoming materials are checked and inspected for conformance to agreed specifications. All dispatched products are inspected for quality and aesthetics.
The following gases are available from AFC International in single or multigas combinations. We can custom mix certain gases for your requirements. For pricing, please call AFC International at 1-800-952-3293, 219-987-6825 or fax 219-987-6826 or email firstname.lastname@example.org.
|Hydrogen Cyanide||Hydrogen Sulfide|
|Methyl Chloride||Methylene Chloride|