RESINOGRAPHY 



of examination of the combination would to examine the surfaces of Type IV particles, 



probably follow the techniques of metallog- inserts, laminates, possible cracks and voids, 



raphy and microscopy by reflected light. If etc. of fabricated, cut or fractured surfaces 



the resin is combined with rock, mineral during manufacture, test or use. Only mor- 



or ceramic, the techniques would be related phology is revealed and such information is 



to petrograph}'^ and transmitted light, or min- limited ; optical properties or patterns can- 



eralograph}^ and reflected light. not be studied without provision for polariz- 



If common amounts of pigments or fillers ing the light, 



are added to the resin, the product is gen- In the resinographical laboratory three 



erallj'^ so opaque that reflected light is the general kinds (2) of compound microscopes 



only light-microscopical illumination feasi- will be essential if all 4 types of units are to 



ble. It is very satisfactory. be considered. These microscopes, in the 



recommended order of their acquisition are: 



Equipment (^^^ Stereoscopic, hiobjective (Greenoiigh) 



If the resinographer is in a narrow field light microscope for preliminary work and 



of making, fabricating, testing or using res- some units of Types IV and III (q.v.,p. 538). 



ins, his microscopical equipment, accessories (2) Monoobjective, 'polarizing light micro- 



and techniques may be definitely specified, scope ecjuipped for both transmitted and re- 



If, however, the resinographer is in research, fleeted illumination for more precise work 



development, consulting or a very broad with units of Types IV and III and some 



field of manufacture or use, he will need a units of Type 11. 



wide variety of equipment, accessories, tech- (3) Electron microscope, especially for 



niques, experience and personal help. Fur- seeing morphology of units of Type II and, 



thermore, the manufacturer of resins which at highest powers and best performance, 



are to be sold for many purposes may have some units of Type I. 



a much broader interest in the texture. Stereoscopic Microscope with Polars. 

 structure and combination of a resin than The kind of microscope recommended for 

 the fabricator or consumer who has a specific preliminary examination, preparation, mi- 

 interest. Indeed, the resinographer of a cromanipulation, and experimentation on 

 primary manufacturer has broad interests resinous materials is the Greenough type, 

 and responsibilities of health, safety, com- biobjective, stereoscopic microscope fitted 

 petition, "security" and fundamental re- with polars (2). This type of microscope is 

 search ; his microscopical equipment must be generally excellent for the examination of 

 as versatile as he is. particles (IV) of moldable or molded grains, 



Away from his laboratory the experienced crystalline aggregates, some fillers, most 

 resinographer finds that he can recognize inserts, many foreign particles, most 1am- 

 and study resins a great deal better with a inates; some single crystals, multi-phase 

 simple magnifier (3) than with the unaided systems, most cracks, many voids. The ob- 

 eye. For example, a lOX pocket magnifier, jectives have such long depth of focus {ca. 

 correct for aberrations, can be carried at all 25 m) that the object might be studied as it 

 times. It gives an erect, virtual image that is is or after fracturing, cutting, sawing, and/or 

 easy to interpret. Its chief disadvantage is abrading into thick or thin sections to reveal 

 that it must be held close to both the object all of the pertinent views. 

 and the eye. This simple magnifier or a Reflected illumination, whether direc- 

 pocket compound microscope (3) is recom- tional, or symmetrical, is typically dark- 

 mended for field work, within limits and field in the Greenough microscope. That is, 

 within the experience of the resinographer, the illuminator is outside the objectives, and 



532 



