Lidstrom:UV-2401PC UV-Vis recording spectrophotometer: Difference between revisions

Revision as of 06:52, 13 December 2013

Manual page 3: The light source is turned on by the personal computer under specific conditions, as follows:

When both START and END wavelengths are within the range from 190nm to the switching wavelength, only the D2 lamp will be turned on.
When both the START and END wavelengths are within the range from the switching wavelength to 900nm, only the WI lamp will be turned on.
When one wavelength falls below the light source switching wavelength and one above, both D2 and WI lamps will be turned on.

In the UV-24OlPC, the positions of the light sources are adjusted automatically, ensuring that maximum intensity is obtained from the detector every time the power switch is turned on.
All the optical elements except light source are sealed from the atmosphere by the windows W, to keep them dust-free. This is one of the features of the UV-2401PC. The slit width is selected

in 6 steps; 0.1, 0.2,0.5, 1, 2,5.

In normal measurement, a slit width of 2nm is considered appropriate.
The monochromator is composed of Sl (entrance slit), M2 (mirror), G (grating), M3 (mirror) and S2 (exit slit). The mounting is of the Czemy-Turner type, characteristically providing little aberration.* The Shimadzu-designed blazed holographic grating with 1600 lines/mm provides high optical energy with minimal stray light.
The images of the exit slit S2 are focused at the cell position in the sample compartment.
Figure 3-5 shows the relationship between the position of cell and light beam. The cross section of the light beam on the cell is about lmm wide and 12mm high when the slit width is 2nm.
When a micro cell of narrow width below 2mm is used, it is recommended that the optional cell holder with mask (P/N 204-06896) or the optional super micro cell holder (P/N 206-14334) can be used. In addition, a black masked cell is preferable for decreasing the influence of the scattered radiation.