High-efficiency filters and filter media for removing particles in air. Aerosol production, measuring equipment and particle-counting statistics|Humidity measurement, Efficiency, Aerosols, Performance testing, Maintenance, Dispersions (chemical), Test equipment, Inspection, Air filters, Specimen preparation, Classification systems, Measuring instruments, Particle size measurement, Statistical methods of analysis, Error correction, Clean rooms, Accuracy, Ventilation, Filters, Calibration, Air cleaning equipment, Air-conditioning systems, Pressure testing, Physical property measurement