<\/div>\n
Types of counter<\/h2>
Particle counters differ in: sampling flow rate (0.1 CFM \u00b7 2.83 L\/min for rapid spot measurements; 1 CFM \u00b7 28.3 L\/min for measurements over significant volumes); minimum detectable particle size (0.1 \u00b5m for critical pharmaceutical environments, 0.3 \u00b5m for standard industrial applications); portable or benchtop (for manual inspections) versus fixed remote units (for continuous cloud-based monitoring with alarms). Airborne models (for atmospheric air) and liquid models (for pharmaceutical and injectable liquids) are intended for different applications. <\/p>
Cleanrooms and ISO 14644 classification<\/h2>
ISO 14644-1 classifies cleanrooms according to the maximum permitted concentration of particles per cubic meter: ISO class 1 (\u2264 10 particles \u2265 0.1 \u00b5m\/m\u00b3); ISO 3 (\u2264 1,000); ISO 5 (\u2264 3,520, formerly Class 100 in the US standard); ISO 7 (\u2264 352,000, formerly Class 10,000); ISO 8 (\u2264 3,520,000, formerly Class 100,000); ISO 9 (\u2264 35,200,000, filtered ambient air). Certification requires measurements following the ISO 14644-3 procedure, with sampling on regular grids across the whole room, in the \u201cas built\u201d, \u201cat rest\u201d and \u201cin operation\u201d states. The counters used must comply with ISO 21501-4. <\/p>
HEPA filter integrity testing<\/h2>
One of the most important applications is integrity testing of the HEPA\/ULPA filters installed in cleanrooms: the PAO test (using PAO oil aerosol or equivalents) involves injecting an aerosol of known concentration upstream of the filter and scanning downstream with a particle counter to identify any leaks (localized escapes of particles). The scan is performed by slowly moving the counter probe along a grid of passes over the entire filter surface. Compliance is required for the certification of pharmaceutical GMP rooms (EU Annex 1) and is standard practice in IQ\/OQ\/PQ qualifications. <\/p>
Industrial and environmental applications<\/h2>
Beyond cleanrooms, particle counters are used for: monitoring workplace air quality (checking exposure to dust from machining, pharmaceutical products or ceramics); monitoring industrial environments with controlled contamination (electronics, semiconductor and microelectronics production lines); inspecting HVAC ventilation and filtration systems; outdoor environmental monitoring of PM2.5 and PM10 (for scientific research and smart cities); advanced IAQ applications (indoor air quality in buildings); and monitoring emissions from industrial processes.<\/p>
Reference standards<\/h2>
The main standards are: ISO 14644 (parts 1-12 – classification, testing and monitoring of cleanrooms); ISO 21501-4 (requirements for optical particle counters); EU GMP Annex 1 (pharmaceutical, microbiological and particulate contamination); IEST RP-CC006 (USA, recommended practices for cleanrooms); UNI EN 12469 (biological safety cabinets). Periodic calibration of counters follows ISO 21501-4 using certified reference particulate of known size (PSL – polystyrene latex spheres). The interval is annual for regulated applications and six-monthly for intensive critical use. <\/p>
Selection criteria<\/h2>
The choice of particle counter depends on: the ISO 14644 class of the environment to be certified (minimum particle size, sampling flow rate); the application (cleanroom, IAQ, environmental, filters); portable versus fixed remote use (for continuous monitoring); compliance with 21 CFR Part 11 (for FDA pharmaceutical use); integration with cloud-based remote monitoring systems; management software compliant with GMP procedures; and an ISO 17025 accredited calibration service from the supplier.<\/p>","protected":false},"excerpt":{"rendered":"
Particle counters for cleanrooms, IAQ and dust monitoring.<\/p>\n","protected":false},"author":157040980,"featured_media":0,"parent":19489,"menu_order":10,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_yoast_wpseo_focuskw":"","_yoast_wpseo_title":"","_yoast_wpseo_metadesc":"","_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_wpcom_ai_launchpad_about_page":false,"_wpcom_ai_launchpad_gallery_page":false,"_wpcom_ai_launchpad_contact_page":false,"_wpcom_ai_launchpad_events_page":false,"_wpcom_ai_launchpad_video_page":false,"_wpcom_ai_launchpad_portfolio_piece":false,"footnotes":""},"class_list":["post-22208","page","type-page","status-publish","hentry"],"yoast_head":"\n
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