The Split Pea™ Hemi Micro ATR Sampler has the smallest sampling area of any ATR accessory. The hemispherical optic design is well matched to the refractive indices of the crystal materials and results in concentration of the beam by a factor equal to the refractive index of the material (3.4 for Si and 2.4 for diamond), thereby minimizing stray light and shrinking the sample area. The small sample area – 250 µm for a Si crystal and 500 µm for a diamond crystal – translates into easier alignment of small samples in the beam and the ability to apply localized pressure to the sample thereby improving contact between the sample and the crystal at high pressures. Furthermore, the hemispheric optics do not cause the beam to defocus after it strikes the sample as occurs with conventional prisms used in internal reflection spectroscopy (See Fig. 1). The result is enhanced spectral resolution with small and irregular samples.

The Diamond and Silicon optics are hard and inert, making this accessory ideal for fibers, rocks and minerals, paint chips, irregular and curved surfaces, extremely hard samples, microliters of liquids or pastes, and hair. The Split Pea™ is an inexpensive alternative to infrared microscopes and yet considerably more versatile than beam condensers and diamond cells.
The Split Pea™ is equipped with a calibrated pressure applicator for reproducible measurements. It also features Constant Purge™, which maintains the system purge while the sample compartment of the spectrophotometer is open. When purchased with Si optics there are 2 interchangeable sample plates. There is also a specular reflection sample holder, an alignment mirror and a sample holder adapter for studying powders. Options include a 50X view through pressure applicator for precise alignment of micro samples (See Fig. 2), a liquid flow cell attachment, and a combinational chemistry kit. ZnS or ZnSe hemispheric optics are also available.

Features:

• Silicon hemi optics produce an extremely small sample spot
• Diamonds are Forever
• View through alignment option
• Measurable and reproducible high pressure anvil enhances sample contact
• Superb spectral resolution
• Constant Purge™