Mantis 5000 Especificaciones descargar pdf (Pagina 66)

7. Click the Setup button and check the parameters. Normally, the setup parameters for

the application should match those used for the baseline scan. If using a previously

defined baseline correction, retrieve the correct baseline.

8. Click the Start button.

The value displayed by the instrument is the combined transmission. No data correction

is required.

Using the Small Spot Kit

The DRA small spot kit is composed of three lens options that focus the beam to a small

diameter spot at the selected sphere location. The top of each lens is marked as either:

"R" for reflectance port, "T" for transmission port, or "C" for centre-mount location. An

arrow appears next to each lens marking. The direction of the arrow indicates the side of

the lens which should face the sphere. After the desired lens is installed into the lens

holder assembly, it can be moved along its rail to focus the sample beam. When the

transmission lens is installed, the overall beam spot size will change as the lens holder is

adjusted along the dovetail rail. The spot size can be reduced down to 2.5 - 3 mm

diameter at the transmission port. For controlling beam size at the centre-mount or

sample reflectance port locations, the iris should be used in conjunction with the

corresponding lens. For the reflectance beam spot, the iris assembly can be closed to

reduce the spot size from approximately 8 mm tall by 2 mm wide to approximately 3.5

mm tall by 1.5 mm wide. Similar results are achieved with the centre-mount lens and iris

combination. A mask should be fitted over the transmission or reflectance ports when

collecting small sample measurements.

When operating in small spot mode, the sample beam undergoes considerable attenuation

before it reaches the integrating sphere. Increased energy and an expanded slit width may

be required for collecting accurate spectra. When measuring highly absorbing samples, it

may be necessary to attenuate the reference beam. A wire attenuation screen is provided

for this purpose. The screen is designed to fit at the entrance port for the reference beam.

The reference beam energy should be attenuated so that it matches the sample beam

energy in its most reduced state. Consult the Cary instruction manual for more

information on instrument requirements regarding sample and reference beam energy

balance.

Note

A reflectance port aperture kit, Labsphere Part No. AS-02021-000, is available

through your Varian representative to reduce the DRA reflectance port diameter to

better suit small samples. The kit consists of five different aperture plates which

mount on the reflectance port dovetail rail. These plates effectively change the

reflectance port diameter to 1”, 0.5”, 0.375”, 0.25”, or 0.15” (25 mm to 4 mm

diameter). A special sample restraining clamp is provided, and it can be fitted with

one of five suitably sized spacers to adapt to any sample size.

1 2 ... 61 62 63 64 65 66 67 68 69 70 71 ... 87 88

Sin comentarios

Mantis 5000 Especificaciones Pagina 66