INFICON Composer Elite Gas Concentration Monitor - Manual (Page 63)

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Composer Elite Operating Manual
4.1.9 What is the Long Term Stability of
this Measurement System?
There does not appear to be any trend that might lead to any unexpected wear or
degradation with time. This data is not corrected for zero offsets due to atmospheric
pressure variations over the test period.
Using R134a in nitrogen as a test (R134a is similar in molecular weight to some
common metal organic precursor gases), the chart shown in
Figure 4-5 shows
stability of +/- 5 ppm over 112 hours, even as the ambient temperature
varies by 3°C. This is equivalent to <1 ppm trimethylIndium in hydrogen.
Figure 4-5 Long term reproducibility and stability at low pressure