This is description of this part:
Achromatic 100x Will Wetzlar microscope objective - an interesting piece for collectors - with a factory engraving error.
This is a fully functional microscope objective, and its technical specifications are described below. However, this particular example may be of interest to collectors of microscope equipment.
The objective is designed for a tube length (TL) of 160 mm and corrected for use with a 0.17 mm thick cover glass. The engraving on the objective barrel should therefore read:
160/0.17
but the metal barrel is engraved:
0/0.17 - meaning the two leading digits, "1" and "6", are missing.
This is not a painted marking that has worn off, which is very common. It is a machine engraving that was defective straight from the factory.
Manufacturer: Will Wetzlar
Magnification: 100x
Model: 160/0.17 Oel 100/1.25
Actual engraving: 0/0.17 Oel 100/1.25
Type of error: incomplete engraving of the specifications on the barrel
Numerical aperture N.A.: 1.25
Cover glass: yes, 0.17 mm
Thread: RMS
Tube length: 160 mm
Parfocal length: 37 mm
Immersion: yes, oil
Eschenbach, Kremp Wetzlar, CBS Beck Kassel, Kosmos Stuttgart and Hund Wetzlar also used objectives made by Will Wetzlar, although these often carried their own brand name. It is therefore quite safe to say that this objective will fit microscopes from these companies - but it is worth checking the parfocal length first (37 mm or 45 mm).
This objective fits practically any microscope from any manufacturer, as long as it has an RMS thread and accepts objectives with TL=160 mm and a parfocal length of 37 mm. Some example microscopes are listed in the "compatibility" section, but the list is not exhaustive.
What is this part needed for?
- if you want to add a curiosity to your collection, such as an objective with a factory error in the engraving of the specifications on its metal barrel
- if you own a Will Wetzlar microscope without a 100x objective and want to complete it with original parts
- if you are looking for a good quality 4x objective for a microscope from another manufacturer
- if you already have such an objective, but it is in very poor condition and you want to replace it with a working one
- if you want to keep such an objective as a spare
