Guide to Particles in Transformer Oil

Guide to Particle Identification

This is part of a guide to the identification of particles seen in samples of transformer oil. It is designed to allow access to files using any significant feature noticed by the microscopist rather than requiring a specific set of measured parameters. Often the most significant feature of a particle is unique to that particle type and so is not a useful diagnostic element for a broader Key for particles in general. This guide will lead to the same particle through a number of different paths depending on features and the order of significance placed on those features by the microscopist/analyst. When a particle is found that appears to be similar to the one being identified it may be useful to go to the file of particles of that type. For instance, if it looks like a starch grain then it may be useful to go to the "Starch" file in this gallery and see a larger variety of starch grains for comparison.

Round or Spherical Particles

Spherical Particles Black with Transmitted Light and Colored with Reflected Light

Spherical Particles Black with Transmitted Light and with Reflected Light

Spherical Particles Transparent with Transmitted Light and Dark between Crossed Polarizing Filters

Spherical Particles Transparent with Transmitted Light and Bright between Crossed Polarizing Filters

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Particles that look Black with Transmitted Light

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Agglomerated Particles

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Anisotropic Particles

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Barbed Particles

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Cellular Particles

Colored Particles

This file includes transparent particles of any shape that have a predominant color when viewed without polarizing filters. Clothing Fibers and paints can be any color and should be keyed out as "Fibers" or, in the case of paints, as spheres or agglomerates.