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Compound achromatic stereo microscope

Maker

МБС (MBS)

Country

USSR

Signature

МБС-1 / Made in USSR / 747152

Category

Microscopes

Optical 1

Compound

Optical 2

Achromatic

Size of the microscope (h x b x d)

36 × 21 × 21 cm

Inventory number

SM 10

Description

Stereo microscope for incident and transmitted illumination. The microscope is mounted on a circular metal base plate, in which a large recess for a glass object plate. There is a bracket for a lamp mounted near the front lens. Focussing is by means of rack and pinion.
The base plate can be mounted on a circular box as well, there are arm rests and in the box a mirror that can be adjusted by means of a handle. The front of the box is open, allowing light to enter.
With this instrument are three sets of eyepieces, ‘6×’, ‘8×’ and ‘12.5×’, their diameter is 30 mm. In the ‘8’ eyepiece a micrometer can be placed.

Eyepiece 12,5×
Focal length (mm) 42.9 30.3 19.8
Magnification 5.83 8.25 12.63

The optical system of this microscope uses in front an achromat followed by a magnification changer and a beam splitting prism combination, followed by a correction lens in each of the two eye tubes. The eyepieces in combination with their correction lens make up telescopes adjusted for infinity, in this way changes in the optical path length caused by changing the interocular distance have no influence on the focussing and the magnification.
The magnification changer has a neutral position, in this case the magnification is 2×. The other positions are 0.6×, 2×, 4× en 7×.
The objective system was measured on the microscope itself, in the 0.6×, 1× en 2× positions with the set of ’12.5’ eyepieces, in the 4× and 7× positions of the magnification changer with the ‘6×’ eyepieces.

Position 0.6×
Magnification 7.20 12.70 25.58 23.6 42.98
Numerical aperture 0.023 0.039 0.082 0.078 0.099
Resolving power (µm) 10 6.5 6.5 4