urn:nasa:pds:context:instrument:arc-ocf.thermo-fisher_is50-ftir-spec 1.0 1.25.0.0 Product_Context 2026-04-14 1.0 Initial creation of the context product. urn:nasa:pds:context:facility:laboratory.arc-ocf instrument_to_facility Thermo Fisher iS50 FTIR Spectrometer Spectrometer Visible Near-Infrared Infrared Far-Infrared The Thermo Fisher iS50 FTIR spectrometer allows spectroscopic characterization of the spectral properties of samples from 0.6 to 200 µm (17,000–50 cm–1). This wide wavelength range is made possible by the availability of four different detectors [Si (visible, Vis), TEC-InGaAs (near infrared, NIR), DLaTGS-KBr (mid-infrared, MIR), DLaTGS-Polyethylene (far infrared, FIR)] and four different beamsplitters [Quartz (Vis), CaF2 (NIR), KBr (MIR), Solid Substrate (FIR)]. An automated exchanger allows full spectral coverage without breaking purge. The spectra can be measured with a resolution as low as 0.5 cm-1. Two Harrick Scientific accessories, the Variable Angle Transmission Accessory (VATA) and the SEAGULL variable angle reflectance accessory, can be coupled to the FTIR spectrometer to allow the characterization of the optical properties of solid samples, over a broad range of incidence and emittance angles, from 0° to 90° for the VATA accessory, and from 5° to 85° for the SEAGULL accessory. The VATA and SEAGULL accessories enable the characterization of the angular light distribution in both transmission and reflection measurements.