Operation Manual TCH Pro 202 & 203
Chapter 3: Theory of Operation
A clean, contamination-free work environment is critical to maximize yields as certain
particles are likely to cause defects, irregularities, inaccuracies and even failures. Analyzing
particle contaminants is an important step in having control over operating environments
and reducing particle deposition in critical components.
Isolating, characterizing and understanding the types of particles found in products or
processes can usually yield a likely source for the particles. Once the source is known then
elimination of the particulate contamination becomes substantially easier.
II. PARTICLE DETECTION
PARTICLE COUNTING PRINCIPLE
A particle counter is an instrument that detects and counts particles. A particle counter
works on the principle of either light scattering, light blocking, or condensation for detecting
and measuring particle size or size distribution.
When a particle is illuminated by a light beam, light is reemitted (if light scattering is used) or
absorbed (obstruction). The scattered or absorbed light (depending on method used) is
detected by a photo detector, measured, and the particle is counted and tabulated into
standardized counting bins. If direct imaging is used, light illuminates particles from the back
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TCH Pro v1.2.1
