Inficon HAPSITE ER, Operating Manual, Page: 426 / 436

21 | Appendix B: Calibrating Gas Mixtures INFICON
426 / 436 074-471-P1E HAPSITE ER Operating Manual
21 Appendix B: Calibrating Gas Mixtures
21.1 Acquisition, Preparation, and Handling
CAUTION
Failure to calibrate the instrument may give you inaccurate
identifications when sampling.
WARNING
When using chemicals, wear the appropriate PPE according to SDS.
HAPSITE ER (or any GC/MS instrument) must be calibrated at one or more
concentration levels of the organic compound(s) of interest for quantitative analysis. In
the case of the HAPSITE ER, the compounds of interest must be supplied to the
instrument as a gaseous mixture of known volume/volume composition (mole/mole %
or ppmv levels in air or nitrogen) and at atmospheric pressure.
There are a number of important factors to consider in acquiring, preparing, and
handling gaseous standard calibration mixtures. These can be organized in three
groups:
1. How to establish the desired concentrations of the required compounds. See How
to Establish the Desired Concentrations [
}
426].
2. Correct delivery of the mix to the inlet of the HAPSITE ER. See Correct Delivery of
the Mix to the Inlet of the HAPSITE [
}
428].
3. Gas cylinder safety, contamination checks, and corrective steps in equipment. See
Gas Cylinder Safety, Contamination Checks, and Corrective Steps [ } 430].
21.1.1 How to Establish the Desired Concentrations
There are two basic ways to obtain several concentrations of a given mix of
compounds. The compounds can be bought, premixed to specification, in cylinders
containing the several concentrations desired. A master cylinder of the compounds
can also be purchased at the highest concentration needed, and diluted to the lower
required concentrations. Each of these options is discussed in the following sections.