Purity Analysis of Gases Used in the Preparation of Reference Gas Standards Using a Versatile OPO-Based CRDS Spectrometer

Figure 5

Measurement of CO₂ in high purity nitrogen using different kinds of tubings. The flow rate is 30 L/h. The observed CO₂ amount fractions are 2 nmol/mol for 2 m long stainless steel () tubing, 85 nmol/mol for 10 m long PTFE (), 14 nmol/mol for the ca 1.2 m long FEP (), and 5 nmol/mol for the ca 0.6 m long FEP ().