Acetylene 13C (13C2H2) Reference Cell.
These flame-sealed cells contain 50 Torr of >99.9% chemically pure, isotopically pure 13C acetylene (13C2H2) at room temperature. They are used for calibration of tunable lasers around 3200-3350 cm-1 (2985-3125 nm). Acetylene's spectral features are especially useful for spectroscopic calibration of other alkynes or Csp-H stretch transitions. Acetylene is also a NIST Telecom Standard Reference Material (SRM) 2517a.
The quartz cell body is cylindrical in shape; outer diameter 10 mm; length 50 mm. The tipoff stem is centered on the cell, protruding not more than 8 mm from the cell body. Windows are angled 11° off of normal and have a 2° interior wedge to prevent back-reflection and etalon effects.