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This accessory integrates advantages of our Meridian™ diamond micro-ATR with video imaging and force sensing capabilities, making the Video Meridian™ the accessory for analyzing small, hard, corrosive or irregularly shaped samples.
The Video Meridian can be configured for either ATR or external reflectance, simply by changing the sample holder. In its ATR mode, it features a sample holder with a monolithic hemispherical diamond ATR crystal for operation from the mid-IR to the FIR. The sampling surface on the diamond is less than 500µm in diameter and is horizontally oriented for convenient sampling. A video system images through the crystal, providing a magnified real-time picture of the true sampling surface. This image can be viewed on the optional LCD display or a computer screen. Software is included to capture the image for a permanent record. For analysis, the samples are compressed against the sample using a force-sensing pressure applicator. This pressure applicator is equipped with an adjustable alarm, to easily deliver repeatable and reproducible contact pressures. For external reflectance and re-alignment, the Video Meridian™ features a removable sample holder and reference mirror. The Video Meridian™ is enclosed in a purgable box for rapid sample exchange without interrupting the purge of the system.
Optional accessories for the Video Meridian™ include:
- An LCD display with a 4" monitor. The display provides a 44X magnification of the image and can be affixed to the front of the accessory or rested on its stand nearby.
- A liquid cell which seals to the crystal holder with an o-ring and features two luer fittings for flow or static applications.
- A powder retainer that o-ring seals to the crystal holder and contains powders during analysis
Representative spectra recorded with the Video Meridian™ are shown in Figures 1 through 4. All spectra were recorded with 32 scans and 8 cm-1 resolution with a DTGS detector.
Figure 1. ATR Spectra of a 20 um PET Fiber compressed with 20 (top) and 302 (bottom) units of pressure.
Figure 2. Photographs of the 20 um PET Fiber compressed with 20 (left) and 302 (right) units of pressure.
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Figures 1 and 2 show spectra and photographs of a 20 um diameter PET fiber compressed with different contact pressures. The photographs clearly show how much the fiber was flattened during pressure application.
Figure 3 shows spectra of two pulverized rocks. The spectra show that the white rock is composed mostly of quartz and the brown rock has a significant amount of chromite. The inserts show the differences between the two in texture and color.
Figure 3. ATR Spectra of White (top) and Brown (bottom) Rocks.
Figure 4. ATR Spectrum of the Bottom (lower) and Top (upper) Surface of a Gray Floor Paint Chip.
For Figure 4, spectra were measured from the exposed side and underside of a paint chip. The two surfaces have different chemical compositions, and the spectra indicating that the top surface is an alkyd resin while the bottom is mostly cellulose.
As demonstrated by the above examples, the Video Meridian™ is a versatile sampling tool for examining a wide range of solids, liquids and pastes.
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