What major feature distinguishes transmission electron microscopy (TEM) from PCM?

Transmission electron microscopy (TEM) is distinguished from PCM (Phase Contrast Microscopy) primarily because it has the capability to identify and characterize different fiber types with a high level of accuracy. TEM operates by transmitting electrons through a thin sample, offering resolutions that can visualize structures at the atomic level. This high resolution enables researchers to differentiate between various types of fibers, such as asbestos and other respirable particulates, based on their morphology and size.

The ability of TEM to provide detailed images at such fine scales is crucial for industrial hygienists and researchers who need to assess workplace exposures to hazardous fibers. PCM, while useful for detecting the presence of fibers in bulk material, does not have the same level of resolution or ability to characterize specific fiber types.

Additionally, the other options do not accurately characterize the strengths and applications of TEM in comparison to PCM. TEM is recognized for its greater accuracy and spatial resolution, rather than being less accurate; it has a much higher resolution than PCM rather than lower; and, while TEM can be used in research contexts related to OSHA compliance, it is not typically the primary tool for compliance assessments as PCM is more suited for counting fibers in air samples to evaluate exposure risk.