Aerosol diluters can be used in cases where a particle counter is used for recovery testing of a cleanroom of ISO class 6 and 7. The high particle concentrations can pollute the internal optics of the particle counter, the diluter can be used together with any particle counter with a 1 CFM flowrate. The diluters are available in 1 10:1 or 100:1 dilution ratio. The diluters are ideal to use for Isolators, Mask fittings and installations with low airlows. The diluter work with any type of aerosol challenge, including PSL, PAO, DOP and NaCl.