Bresser Science MTL 201 50-800x Metallurgical Microscope

The Science MTL 201 is a reflected-light metallurgical microscope, for a metallography, materials or electronics lab that needs to look at opaque, polished surfaces at 50x to 800x. In a reflected-light microscope the light comes down through the objective onto the sample and bounces back up, so the sample doesn't have to be thin or transparent. Bresser lists polished metal and alloy samples, minerals, precision engineering and electronics, in research, teaching and production quality control.

A halogen lamp with a dimmer feeds the vertical illuminator. In its path are a centrable field diaphragm, filters (yellow, green, blue and ground glass) and a polariser and analyser pair, which bring out grain structure and inclusions. The five objectives are plan-achromatic DIN lenses, 5x, 10x, 20x, 40x and 80x, on a five-position nosepiece; plan-achromatic means the image is flat to the edge and corrected for colour fringing. The WF10x eyepieces sit in 30-degree tubes with dioptre and eye relief adjustment, and the trinocular head has a photo tube for a camera.

The stage is 250 by 230 mm, big enough for a whole circuit board. A quick-release lever moves it coarsely and two knobs move it finely along and across. Samples up to 29 mm tall fit under the objectives. Focus is coaxial, coarse and fine, with roughly 70 microns of travel per turn of the fine knob, which a flat polished surface at 800x needs.

In the box are the microscope, two WF10x eyepieces, the five objectives, the coaxial stage, the colour filters, a dust cover and a power cable; it weighs 16.6 kg with accessories. A camera for the photo tube takes an optional adapter, and our microscope camera guide covers the options. The Science ADL 601 P below it has reflected and transmitted light with polarising at up to 600x, and our microscopes for electronics run from USB models up to this one.