Leica DMI6000B, DMI3000B, DMI4000B manual Start-up

7. Start-up

¥Switch to the 10x objective (if not present, the 20x objective).

¥Ensure that the condenser is at the correct height. The condenser height adjustment lets you set the condenser head to the height of the nominal free working distance. (For an S23 condenser, for example, the distance between the surface of the stage and the front lens of the condenser is approx. 23 mm).

¥Hold a piece of white paper (approx. 3-10 cm)

under the light source (field diaphragm). A light ring should appear on the paper Ð if not, check the power cable, the light source and the fuse of the supply unit (CTR box) and ensure that all of the parts are correctly con- nected to one another.

¥Open the field diaphragm as far as possible until the light ring reaches its maximum diam- eter.

¥Next, hold the paper under the condenser, di- rectly on the stage. Open the aperture dia- phragm as far as possible, until the light ring has reached its maximum brightness. In order to achieve maximum brightness, ensure that no port is activated. The full light should be di- rected to the VIS port.

¥Check the magnification changer to ensure that the 1x tube lens is selected.

¥Adjust the lenses of the eyepieces so that one circle is visible in the eyepieces (not two!). If you wear spectacles, remove the antiglare hoods from the eyepiece tubes (or fold them back).

¥Ensure that the focus on the eyepieces is set to ±0 (turn the upper part of the eyepiece

tubes until the silver ring is just covered).

¥You should see light when looking through the eyepieces at this point.

If the light is too bright, reduce it as required.

Remove all unneeded components from the light path.

¥Swing all filters (in the filter magazine of the lamp housing or the filter holder of the con- denser) out of the beam path.

¥Set the condenser disk to the bright field posi- tion.

¥If your microscope is equipped for DIC:

¥Remove the polarizer.

¥Remove the analyzer.

¥Remove the objective prism (move the magazine to the ÒemptyÓ or Òbright fieldÓ position).

¥If your microscope is equipped for fluores- cence:

¥Select an empty filter position (or a filter with low transmission in the visible range, e.g. filter A).

Now to begin with the actual Koehler illumina- tion:

¥Place your specimen on the stage and focus so that you can see its details as clearly as possible. You probably will not get a perfect image at this point, as the illumination will not be optimal (90a).

¥Next, attempt to get a sharp image (or at least a part of the image at the edge) by carefully moving the condenser up and down (90.2). Try this with a variety of field diaphragm settings until you get a clear, sharp image (91.b). This may take a while!

¥To center the sharp image, insert the centering keys in the openings provided at ei- ther side of the top part of the condenser (90.1). Move the image into the center of the field of view (91.c). Next, open the field dia- phragm until the image fills nearly the entire

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