Thermo Scientific™

Smart iTR™ Attenuated Total Reflectance (ATR) Sampling Accessory

Eliminate sample preparation while retaining exceptional throughput with the ultra-high-performance, versatile Smart iTR Attenuated Total Reflectance (ATR) Sampling Accessory. Primarily designed for use with a single bounce diamond crystal, the Smart iTR Accessory also offers other options for full configurability. It provides exceptional sensitivity and IR throughput.
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  • Ideal for the analysis of solids, liquids, pastes and gels
  • Available with different crystals for diverse sampling needs
  • Single reflection crystal for general purpose material identification
  • Optional three reflection crystal for increased sensitivity
  • Optional specular plate gives extra flexibility when analyzing coatings on reflective materials
  • Crystal plates are pinned in place with quick-release mounting for easy removal for cleaning or swapping and reproducible insertion with no alignment required
  • ATR crystal plates are backed with a ZnSe focusing optic for optimal performance
  • Large top plate accommodates most samples
  • PTFE coated plate lifts clear easily for simple clean-up
  • Precision machining and an nonreactive gasket provide a tight interface between the top plate and the crystal housing, so spills are not a problem
  • High pressure clamp calibrated to deliver up to 10,000 psi of pressure and comes with interchangeable tips for hard, soft and pellet shaped samples
  • Active Sample Area: 1.5mm for the single bounce ATR and 6mm for the 3 bounce ATR
  • Specular Plate: Spectral range dependent on spectrometer; incident angle is 45°
The Smart iTR accessory can be ordered with three common ATR crystals fixed in stainless steel as standard: diamond, ZnSe and germanium. Each crystal performs strongly under specific circumstances.

Diamond ATR Crystal


  • Inert and robust — excellent for the analysis of hard, abrasive, reactive, caustic or corrosive materials
  • A multi-purpose ATR with a depth of penetration of over 2μm at 1000cm-1 and is used with a wide variety of samples
  • Five-year warranty provided
  • Configuration can be validated
  • Disadvantage — intrinsic absorbtion from approximately 2300 to 1800cm-1


  • Low wavenumber cutoff: 650cm-1 (due to ZnSe lens)
  • Depth of penetration: 2.03μm at 1000cm-1
  • Refractive index: 2.4
  • Useful pH range: 1 to 14 (ZnSe 5 to 9)
  • Incident angle: 42°

ZnSe ATR Crystal Features

  • Most common ATR crystal — provides an excellent performing, lower cost option for general analyses
  • Offers similarly outstanding throughput and a depth of penetration similar to diamond
  • Can be used for a wide variety of samples, but is soft and not as chemically inert as the other crystals
  • Over time it can be etched by acids and scratched by hard samples, which will eventually reduce sensitivity
  • Configuration can be validated


  • Low wavenumber cutoff: 650cm-1
  • Depth of penetration: 2.03μm at 1000cm-1
  • Refractive index: 2.4
  • Useful pH range: 5 to 9
  • Incident angle: 42°

Germanium ATR Crystal


  • Hard and inert (although not as robust as diamond) with a high refractive index
  • Provides a much shallower depth of penetration, making it ideal for highly absorbing or scattering samples such as carbon-black containing rubbers
  • Provides huge performance through the mid-IR range, with upwards of 50% transmittance
  • Offers a limited range, but good chemical resistivity to both acids and bases


  • Low wavenumber cutoff: 700cm-1
  • Depth of penetration: 0.67μm at 1000cm-1
  • Refractive index: 4.0
  • Useful pH range: 1 to 14
  • Incident angle: 42°

Silicon ATR Crystal


  • Hard, with a high refractive index
  • Useful for strong absorbers or abrasive samples
  • Suitable for temperature studies because it withstands thermal shock


  • Low wave number cutoff: 700cm-1
  • Depth of penetration: 0.84μm at 1000cm-1
  • Refractive index: 3.4
  • Useful pH range: 1 to 12 Incident angle: 42°

Compatible with:

The Smart iTR Accessory is compatible with the Thermo Scientific™ Nicolet™ iS™ 10 FT-IR Spectrometer, the Thermo Scientific™ Nicolet™ iZ™ 10 Auxiliary Module, and the Nicolet 6700 and Nicolet 8700 FT-IR Spectrometers.

Recommended for:

  • Most solids
  • Liquids ranging from pH 1 to 14
  • Acidic or alkaline materials
  • Fibers
  • Hard or oddly shaped samples
  • Abrasive, caustic or corrosive materials
  • Large or small samples
  • Paint chips