Most microscope dealers have set standards or grading systems by which to describe the optical, mechanical and cosmetic quality of their pre-owned offerings.  As everyday users of microscopes in our business, not just as microscope dealers, we feel that we are highly qualified to judge the quality and performance of these instruments.  As such, we are very discriminating in our selection of used microscopes.  We only purchase instruments that are complete and in working condition.  We do not purchase "basket cases" or various parts from which to reconstruct an instrument. We are meticulous in servicing and refurbishing our scopes to the best possible condition.   Each and every instrument goes through the following procedures.

We insist that optical and mechanical performance is up to original standards. Any flaws in the optics must be of cosmetic nature and not affect the optical performance of the instrument.  As an example, a tiny flaw in a lens must not be large enough to affect the measurable resolution or contrast of the image.  Generally, depending upon the placement of an optical element in the system, some small amount of obscuration will not degrade optical performance. Therefore, small imperfections, such as tiny marks, scratches in the glass or sleeks in optical coatings, will not affect performance. Any optics that are degraded due to separation of lens elements, sometimes called fogging, are replaced, as this is the largest contributor to loss of optical performance.  Our well equipped machine shop allows us to insure that  mechanical performance will be restored to original.  Cosmetic appearance is as good as possible, but remember that these instruments are pre-owned and as such may show some normal wear.  In some cases, we do repaint components.  Any mechanical cosmetic flaws must be limited to very small scratches, chips or very minor wear marks to the paint.  No gouges, dings or dents are acceptable.  In short, our instruments must perform as close to new as is possible and must appear to be in good, or better cosmetic condition.


Grade Optical (O) Mechanical (M) Cosmetic Appearance (C)
(5) As new Optics are pristine - cannot tell from new Performs and looks as new - no perceptible wear and requires no maintenance or adjustment. Cannot tell from new
(4) Excellent + Optics are extremely clean - performance not limited. Performs as new - cleaned, adjusted and lubricated. Some very small nicks or scratches - must inspect up close to see.  No wear apparent. 
(3) Excellent Optics may have very small cosmetic flaws - performance not limited. Performs as new - has been repaired, cleaned, adjusted and lubricated. Some very small nicks or scratches - very slight normal wear apparent.
(2) Very Good Optics may have small cosmetic flaws - performance not limited. N/A Some small nicks or scratches -  normal wear apparent
(1) Good Optics may have larger cosmetic flaws - performance not limited. N/A Some small nicks or scratches or other cosmetic flaws - normal wear apparent.
Less than Good We do not sell instruments that are below our rating of good.  Scopes in this category are salvaged for parts or sold as salvage.

From the chart above, a rating of O4 M3 C3 would mean that optical rating is excellent +, mechanical condition is excellent, and cosmetic appearance is excellent.


Copyright 1998-2017 by Mineralogical Research Co.
All rights reserved.