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ATR Attenuated Total Reflectance Probe

Posted on: September 16th, 2021


Avantes ATR Probe for measurements of viscous fluids.

Attenuated Total Reflectance is a measurement technique used for incredibly optically dense media such as inks, dyes, coal, and sludge. ATR uses the property of total internal reflection through a crystal resulting in an evanescent wave. A beam of visible or near-infrared light is passed through the ATR crystal in such a way that it reflects several times off the internal surface in contact with the sample. This reflection forms the evanescent wave which extends into the sample medium which may be a liquid, slurry, or solid. The penetration depth into the sample is typically between 0.5 and 2 microns, with the exact penetration value being a function of the wavelength of light, the angle of incidence and the indices of refraction for the ATR crystal and the medium being measured. As the beam exits the crystal, it is collected by a spectrometer

Avantes, North America now offers ATR probe options for use with the AvaSpec instruments. This probe is suitable for nearly any industrial process environment and operates at temperatures ranging from -30°C to 280°C and pressures up to 1200 psi. This sapphire crystal three-bounce design affords a total path length of approximately 1.5 microns and allows response down to 250 nm in samples with a refraction index up to 1.5 or choose the ATR probe option with cubic zirconia crystals for use with samples with an RI up to 1.9.

The body of the ATR probe is made of 316 stainless steel and the jacketing is a PVC-coated stainless-steel armored BX. The single crystal, lacking complex internal optical elements is a rugged option that produces a more stable, flatter baseline and linear response.

Consult with your US sales engineer to inquire about your specific requirements. Available in North America only.


ATR Probe Technical Specifications


Ordering information

Part Number Description
AvaPRB-ATR-S Avantes attenuated total reflectance probe with sapphire crystal
AvaPRB-ATR-Z Avantes attenuated total reflectance probe with cubic zirconia crystal

Download the Data Sheet


Body:  1.75″L  x  0.5″OD
Extension Tube:  4″L x 0.05″OD
Body and Extension Materials: 316 SS ɸ


* Efficiency measured relative to direct fiber connection between light source and detector using a 400 micron-core fiber
** Other fiber lengths available upon request
ɸ Other materials available on request- allow 8 weeks for delivery of custom materials

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