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I have a zeiss std 18 with a monocular polo head with swing in pol and have placed a linear pol on top of field lens,
anything else I may need.
Cheers
Jeff
The specification for the slider doesn’t seem too onerous
■ a removable first order red compensator (of retardation approximately 530 nm);
The area between zero and 550 nanometers is known as the first order of polarization colors, and the magenta color that occurs in the 550 nanometer region is often termed first-order red.
I do not know if they fit asbestos analysis, but one of the best sources for defined nD oils is Cargille (USA). Their oils are also distributed by Amazon and specific laboratory suppliers, (Sigma etc); and are priced accordingly (not for inexpensive hobby use).rs6000 wrote: ↑Fri Nov 08, 2019 7:13 pmseems like the general consensus is quartz ,mica etc sliders are not as important as differing refraction oils
my question now becomes I did not know of anything other then the immersion oil I use for 63x and 100x objectives where do I obtain such a wide variance of oils
Is this something that you want to do yourself or need to do yourself or is it just something that you want done, as in it does not really matter who does it?... maybe I should go to school to learn this stuff I really don't know what to do now
I noticed reference to this DIY project in John Gustav Delly’s recent book:
I wonder if there is a way that they made thin sections in the field. I could see a geologist doing that on remote exploration work where a portable Petrographic microscope would be needed. I work in the environmental industry, it’s not unusual to have a microscopist on site to analyze air samples which is done with a phase contrast microscope. I have rarely seen anyone analyzing bulk asbestos samples in the field. Those are usually sent to a lab prior to doing site work since there is usually some remediation design done before starting a project. On a very large project you may have someone that can do both in which case they would have both microscopes onsite.Chris__R wrote: ↑Sat Nov 30, 2019 7:14 pmSome time ago I boiought a Lomo portable microscope, which is equipped for polarization work. It came in a fitted wood lined metal carry case, with the wedge and wave plates missing but I have managed to find the right ones, to fit their slots. It has the Bertrand lens in the upper part. They appear on ebay now and then.
I wondered why anyone would want a portable geological microscopy - one can hardly prepare 30 micron rock sections in the field! Then I realized, it was likely made with asbestos analysis in mind.
As "pol" microscopes go , it doesn't give any other special features, so what you already have should suit.
My first degree was metallurgy and materials science, so I always intended to use it for inspecting the asbestos-cement roof of my side shed, but never did get around to it! I have a set of refractive index liquids, but I also have not seen the type of objective referred to in the article. The objectives in the Lomo set are slightly unusual magnifications, but not otherwise remarkable.
Source: J. Gregory McHone, CanadaField microscopes can be very useful in biological work, and probably this petrographic scope could also be used for mineral samples such as soil and crushed grains. In the olden days, we would scrape off rock particles into a drop of immersion oil on a slide, and attempt identification via birefringence and relief characteristics. A rock section is much better, but it would be a real trick to make a 30 micron thin section of a rock while living in a field tent, far off the grid!