The FTIR analyzer for measuring impurities in active gases is very similar to the moisture in active gas analyzer except that different special materials and consideration maybe designed into the system. Below is the considerations for impurities in pure fluorine. Impurities in other active gases may require other considerations.
It is best to contact FTIR.com for the requirements for other active gases.
Special Design Considerations for the Impurities in F2 Analyzer
- Pathlength of the cell set for 1.9 meters to 6.1 meters in steps of 0.5 meters
- CaF2 windows (low frequency cut-off 1100 cm-1) sealed with Teflon O-rings
- Gas cell has purgeable secondary containment chamber between the gas cell and the spectrometer
- Windows between the secondary containment chamber and spectrometer are CaF2 using Kalrez or Teflon encapsulated silicone o-rings
- Purge for secondary containment goes to gas detector to alarm if there is a leak in the gas cell windows or Teflon O-rings
- High energy throughput gas cell
- Room temperature DTGS detector for broad range 5000 cm-1 to 400 cm-1 using a KBr beamsplitter or 5000 cm-1 to 600 cm-1 using a optional moisture resistant ZnSe beamsplitter
- "Artificial Reference" software eliminates requirement for reference single beam background spectrum
- FTIR interferometer has dynamic alignment, which provides short term and long term stability and automatic interferometer alignment without operator involvement
- Gas cell has 304 stainless steel conflat flanges, metal - metal seals (copper or nickel) and 304 stainless steel cell body construction for sample wetted surfaces
- Gas cell mirrors have highly protective magnesium fluoride coating over highly reflective gold coating over chemically resistant nickel coating, over solid 316 stainless steel mirror substrate for long term chemical resistance.
- Mirror surfaces are vertical to minimize dust or corrosive particles forming on their surface maximizing time between cleaning
- The gas cell may be refurbished at reasonable costs.
Unpurged Single Beam and Absorbance Spectrum
(plot 4,000 cm-1 to 800 cm-1)
From impurities in 100% F2 system with DTGS detector
Showing low frequency cut-off (CaF2) just below 1,000 cm-1