Particle Count Controls are suspensions of (NIST traceable) particles with closely defined counts per ml. They can be used for the monitoring of liquid particle counters in contamination control applications, for instance in semiconductor cleanrooms. Part of this product line are the 3K4K series, the Pharm-Trol™, Ezy-Cal™ and Count-Cal™ series by Thermo Scientific; and the PharmaCount™ series by Applied Microspheres. These particle count controls are designed to facilitate the control of liquid particle counters in pharmaceutical QC laboratories that need to comply with US, European, Japanese or Korean Pharmacopeia regulations. Part of the PharmaCount™ series is a set of instrument specific controls for the easy calibration of Accusizer instruments, which are commonly used in this environment.