rock crusher within a mining quarry. Sieves are the standard instruments used to measure dry particle size. Vision based systems are also used to measure dry particle size. With a vision based system quick and efficient particle sizing can be done with ease and tremendous accuracy. Specialized types Remote particle counters Small particle counters that are used to monitor a fixed location typically inside a cleanroom or mini-environment to continuously monitor particle levels. These smaller counters typically do not have a local display and are connected to a network of other particle counters and other types of sensors to monitoring the overall cleanroom performance. This network of sensors is typically connected to a facility monitoring system (FMS), data acquisition system or programmable logic controller. This computer based system can integrate into a database, alarming and may have e-mail capability to notify facility or process personnel when conditions inside the cleanroom have exceeded predetermined environmental limits. Remote particle counters are available in several different configurations, from single channel to models that detect up to 8 channels simultaneously. Remote particle counters can have a particle size detection range from 0.1 to 100 micrometres and may feature one of a variety of output options including 4-20 mA, RS-485 Modbus, Ethernet and pulse output. Manifold particle counters Modified aerosol portable particle counter that has been attached to a sequencing sampling system. The sequencing sampling system allows for one particle counter to sample multiple locations, via a series of tubes drawing air from up to 32 locations inside a cleanroom. Typically less expensive than utilizing remote particle counters, each tube is monitored in sequence. Hand-held particle counter A hand-held particle counter is a small, self-contained device that is easily transported and used, and designed for use with Indoor Air Quality (IAQ) investigations. Though lower flow rates of 0.1 ft3/min (0.2 m3/h) than larger portables with 1 ft3/m (2 m3/h), hand-helds are useful for most of the same applications. However longer sample times may be required when performing cleanroom certification and testing. (Hand-held counters are not recommended for cleanrooms). Most hand-held particle counters have direct mount isokinetic sampling probes. One may use a barbed probe on a short piece of sample tubing, but it is recommended that the length of the tubing not exceed , due to loss of larger particles in the sample tubing. Applications Particle counters are used in applications where contamination control in