An Isokinetic probe is a type of Particulate Monitoring probe which is used to measure the amount of particulates in a room that has continuous airflow.
An isokinetic probe collects air at the same velocity as the room airflow to not impact the airflow or movement of particulates in the room.
This isokinetic property is typically controlled through the size of the probe funnel, if the funnel diameter is too small a negative air-pressure will pull more air and more particles giving an artificially high count (Super-isokinetic) and vice versa; too large a diameter will push particles out and generate artificially low counts (sub-isokinetic).
Isokinetic probes are made of a probe funnel, connected via a pipe to a laser counter that can count and size particles through laser diffraction, the air is pulled through by a downstream pump, if the air is pumped out into a plant room filters can be placed on the vent to prevent an open connection from critical areas directly to dirty air. A control system is connected to these laser diffraction modules to count, aggregate and alarm.