The following instructions are one of many methods for arc lamp alignment. The idea is to achieve homogeneous illumination over the field of view for observing and imaging specimens.
A new bulb should always be run for two hours initially to stabilize the arc of the lamp. After the bulb has burned in, the system is ready for arc lamp alignment.
TC Stage
If the arc lamp is not already burning, turn on the power supply and let the arc lamp "settle" for at least 5 minutes.
TC Stage
Place a piece of plastic on the stage that fluoresces with any of the filter sets installed. One may have to find the appropriate color of plastic that fluoresces with the filter sets you have or buy a set of fluorescing slides from Chroma Technology Inc or similar.
Open the filter slider on the illuminator so that the light travels through the system.
Engage the field iris diaphragm all the way open.
Engage the fluorescence filter selector wheel into a position where the plastic specimen fluoresces. If the field-of-view (FOV) is too bright to look at, use a different specimen that is less affected, what is important is that the specimen is consistent or even across the FOV.
While looking into the eyetubes, reach to the centering controls on the lamphouse and adjust both the X and the Y controls to achieve the brightest spot in the center of the FOV or field of view.
While looking into the eyetubes, reach to the centering controls on the lamphouse and adjust both the X and the Y controls to achieve the brightest spot in the center of the FOV or field of view.
While still looking into the eyetubes, turn the knob on the lamphouse which controls the focus of the collector lens assembly. Notice when you turn the knob, that the light spreads outward and inward. Leave the knob in a position in which the light is as even as can be made at this point.
While looking into the eyetubes, reach to the centering controls on the integrated concave mirror. On a TC system, one may need an assistant as it is hard to reach the mirror controls and still be able to see the FOV effectively. Adjust the concave mirror controls in such a way as to reflect the arc back into itself further homogenizing the light in the FOV.
Check the effect achieved when the collector lens focus knob is adjusted and continue to make minor adjustments to the arc position and the mirror position until the light is as even and centered in the FOV as possible.
Remove the plastic slide and place a known good biological fluorescence sample on the stage and again check the effect achieved when the collector lens knob is adjusted and continue to make minor adjustments to the arc position and the mirror position until the FOV displays as even an image as possible.
If a shadow is seen in the FOV, you do not have the field iris centered AND the field iris not open all-the-way.
