Cleanroom qualification, installed-filter integrity and environmental monitoring

Cleanroom Validation, HEPA/ULPA Integrity Testing & Continuous Monitoring

Primionics configures measurement systems for ISO 14644 airborne-particle classification, installed HEPA and ULPA filter-system leakage testing, airflow and pressure verification, recovery studies, airflow visualization and fixed environmental monitoring. Portable qualification instruments, TOPAS aerosol equipment and Kanomax particle and airflow instrumentation are selected around the room class, occupancy state, filter installation, test method and monitoring plan.

ISO 14644-1 airborne-particle classification Installed HEPA / ULPA filter leak testing Airflow, pressure, recovery and visualization Continuous particle and environmental monitoring
Cleanroom classification, installed HEPA filter leak testing, airflow verification and continuous monitoring
Define the qualification basis Identify the cleanroom class, occupancy state, room layout, installed filters, airflow concept, acceptance criteria and applicable procedure.
Classify airborne particle cleanliness Measure particle concentration at defined locations with suitable sample volumes, particle-size channels and calibrated light-scattering particle counters.
Verify airflow and pressure performance Measure terminal velocity, air volume, airflow uniformity, room differential pressure and pressure direction under the specified operating condition.
Test installed filter-system integrity Challenge the installed HEPA or ULPA filter upstream and scan the downstream face, frame, seal and accessible housing interfaces for local leakage.
Establish the monitoring plan Place fixed particle and environmental sensors at critical locations with defined alarm limits, delays, escalation and retained records.
Qualification and monitoring architecture

Qualification proves performance at a defined condition; monitoring provides evidence between qualification events.

ISO 14644-1 addresses classification of air cleanliness by particle concentration. ISO 14644-3 provides test methods for cleanroom performance, including installed filter-system leakage, airflow and recovery-related tests. ISO 14644-2 addresses the monitoring plan used to provide ongoing evidence of performance related to particle cleanliness.

These activities share instruments and data, but they are not interchangeable. A fixed particle sensor does not by itself perform room classification, and a portable classification counter does not by itself create a complete monitoring system.

Qualification evidence supports facility validation; an instrument alone does not validate a cleanroom.
The occupancy state—such as as-built, at-rest or operational—must be stated with the reported result.
Particle-counter suitability, calibration, zero count, counting efficiency and flow verification should match the intended measurement scope.
Cleanroom qualification scope

Measurement coverage for room classification and installed-system performance.

Airborne-particle classification

Configure sampling locations, sample volume, particle-size channels, occupancy state and report logic for ISO 14644-1 classification.

Installed HEPA/ULPA filter-system leakage

Verify the complete installed filter system using an upstream aerosol challenge and systematic downstream scanning of the filter face and installation interfaces.

Air velocity and air volume

Measure terminal-filter velocity, average velocity, air volume and airflow uniformity with probes or capture methods suited to the diffuser and airflow pattern.

Differential pressure and pressure cascade

Verify room-to-room and room-to-corridor pressure differences, pressure direction, stability and alarm behaviour.

Recovery-time measurement

Introduce a controlled particle challenge and record concentration decay to determine the time required to recover to the specified cleanliness condition.

Airflow visualization

Use visible fog to evaluate airflow direction, unidirectional-flow behaviour, turbulence, dead zones and interaction with equipment or operators.

Temperature and relative humidity

Measure environmental conditions where they form part of the facility specification, process requirement or monitoring plan.

Continuous particle and environmental monitoring

Deploy fixed particle, pressure, temperature and humidity points with trend records, alarms, acknowledgement and integration into the facility data architecture.

Installed HEPA and ULPA filter integrity

The leak test verifies the complete installed filter system—not only the filter media.

Installed filter-system leakage testing checks the filter face together with the frame, gasket or gel seal, mounting arrangement, housing interfaces and accessible bypass paths. The exact aerosol, measurement method and acceptance criterion must follow the applicable test procedure and project specification.

Generate the upstream challenge aerosol Introduce a suitable test aerosol into the upstream airflow at a concentration compatible with the method, filter system and facility controls.
Establish representative mixing Confirm that the aerosol challenge is sufficiently mixed across the upstream side of the installed filter system.
Measure the upstream reference Measure the upstream challenge concentration. Apply defined dilution when the concentration exceeds the particle counter's working range.
Scan the downstream installation Systematically scan the filter face, perimeter, frame, seals and accessible housing interfaces with the required probe geometry and scan technique.
Document leakage, repair and retest Record local penetration or leakage locations, complete permitted corrective work and repeat the affected scan area or full test as required.
Measurement-chain requirements

Aerosol generation, dilution, upstream reference and downstream scanning must operate as one traceable method.

A sufficiently strong upstream challenge is needed to detect small local leaks. That concentration can exceed the usable range of a particle counter, making a known dilution ratio necessary for upstream measurement. Downstream scanning then uses the particle counter at its direct measurement range.

The sampling probe, particle-counter flow rate, scan speed, distance from the filter surface and airflow velocity affect the probability of detecting a local leak. The installed system must therefore be tested with a method matched to the filter geometry and airflow condition.

Do not treat a filter-efficiency certificate as proof that the installed filter system is leak-free.
Do not sample a high upstream concentration directly into a particle counter beyond its specified concentration limit.
The test must include accessible perimeter seals and mounting interfaces, not only the central filter face.
Instrumentation stack

Instrumentation selected for the required particle size, sample volume, airflow range and monitoring architecture.

Kanomax portable particle counters

Portable six-channel particle counters support room classification, investigation and verification at model-specific flow rates and particle-size thresholds.

Select by minimum particle size, sample flow, sample-volume requirement, cleanroom class, data handling and calibration scope.

Kanomax 0.1 µm particle measurement

The Model 3950 addresses 0.1 µm and 0.3 µm measurement for high-end contamination-control and semiconductor applications.

Confirm that the required particle size, sample volume, flow rate and classification method are compatible with the project requirement.

Kanomax remote particle and environmental monitoring

Remote particle sensors and cleanroom monitoring architecture support fixed measurement points, trends, alarms and connection to facility data systems.

Define critical locations, tubing length, transport loss, sensor response, network interface, redundancy, alarm logic and data retention.

TOPAS aerosol generation and dilution

ATM aerosol generators create the challenge aerosol, while DIL systems reduce the upstream concentration into the working range of the particle counter.

Specify aerosol material, generator output, dilution ratio, sample flow, facility exhaust and required operating time.

TOPAS cleanroom particle analysis and scanning

Cleanroom particle counters, rectangular sampling probes and CRQWin software support classification, installed filter leakage scanning and structured reporting.

Match counter flow, probe geometry, airflow velocity, scan method and software workflow to the applicable test procedure.

Airflow, air-volume and pressure measurement

Thermal anemometers, micromanometers, capture hoods and application-specific probes support terminal velocity, volumetric flow and pressure verification.

Confirm measurement range, uncertainty, probe access, diffuser type, airflow direction and room operating condition.

Airflow visualization

Controlled fog generation makes airflow direction, turbulence, recirculation and interaction with equipment or operators visible.

Confirm fog suitability, residue requirements, output duration, visibility, ventilation recovery and recording method.

Calibration, verification and records

Calibration certificates, pre-use checks, location plans, raw data, calculations and signed reports form part of the measurement system.

Define calibration interval, as-found/as-left handling, instrument status, user access, audit trail, retention and change control.
Monitoring-system architecture

A monitoring system must be designed around process risk and response—not the number of available sensors.

Critical measurement locations Place particle and environmental points where contamination risk, airflow behaviour and process exposure justify continuous or periodic observation.
Sampling transport Assess tubing length, bends, material, flow rate, particle transport loss, isokinetic sampling needs and sensor response time.
Alarm strategy Define alert and action levels, persistence delays, acknowledgement, escalation, maintenance states and response procedures.
Data integrity and integration Define timestamping, user access, audit trail, retention, backup, report generation and integration with BMS, SCADA or site monitoring platforms.
Facility applications

Qualification and monitoring for contamination-controlled environments.

Pharmaceutical and biotechnology facilities

Support cleanroom qualification, installed-filter integrity testing, environmental investigation and risk-based monitoring for controlled production and laboratories.

Semiconductor and microelectronics cleanrooms

Measure airborne particles down to the required threshold, verify airflow and monitor critical process environments where submicron contamination affects yield.

Medical-device and precision manufacturing

Provide qualification and monitoring evidence for controlled assembly, packaging, inspection and production areas.

Hospitals, operating rooms and controlled clinical areas

Verify airflow direction, pressure relationships, filter-system integrity and particle conditions according to the facility procedure and applicable healthcare requirements.

Cleanroom contractors and validation teams

Configure portable test sets, aerosol equipment, scanning accessories and reporting workflows for commissioning, periodic qualification and troubleshooting.

Research, aerospace and advanced materials

Characterize contamination-controlled spaces used for sensitive experiments, optics, components, materials and high-reliability assembly.

System definition

Technical information required to configure the qualification and monitoring system.

Room and process basis Room dimensions, ISO class, occupancy state, airflow concept, process risk, room drawings and existing monitoring points.
Installed filtration Filter type, quantity, dimensions, terminal arrangement, upstream access, aerosol injection location, seal design and scan accessibility.
Qualification test scope Classification sizes, sample volumes, airflow, pressure, recovery, visualization, integrity method, acceptance criteria and reporting format.
Monitoring and integration Particle and environmental parameters, point count, network, alarm logic, BMS or SCADA interface, user roles, audit trail and data retention.
Frequently asked questions

Cleanroom qualification and monitoring questions.

What is the difference between classification and monitoring?

Classification is a defined test of airborne particle cleanliness at specified locations and occupancy states. Monitoring follows a risk-based plan and provides evidence of ongoing performance between qualification events.

The same instrument may contribute to both activities, but the sampling plan, data interpretation and evidence are different.

What does the HEPA or ULPA integrity test include?

It evaluates the installed filter media, frame, gasket or gel seal, mounting arrangement, housing interface and accessible bypass paths using an upstream challenge and downstream scan.

A filter certificate does not replace testing of the completed installation.

Why is an upstream dilution system used?

The challenge concentration needed for reliable leak detection can exceed the particle counter's direct concentration range. A defined dilution system allows the upstream reference to be measured without overloading the counter.

The selected dilution ratio and flow must match the counter and test method.

Can fixed particle sensors replace ISO 14644-1 classification?

No. Fixed sensors support the monitoring plan, while classification requires specified sampling locations, sample volumes, occupancy state, instrument suitability and classification calculations.

The monitoring layout should be justified independently from the classification sampling map.
Related systems

Connected technologies for cleanroom qualification and facility performance.