ISO 11171: Particle Counter Performance and Calibration

ISO 11171 defines LPC performance specifications directly impacting air particle counters. Operators must understand the standard, determine which calibration steps must be done and ensure their air particle counting equipment meets established performance criteria.

ISO 11171:2016 Calibration Schedule

Instrument Status

Recommended Steps

Routine calibration

Sizing calibration required (Clause 6)

Suspect calibration (> 6-12 months)

Sizing calibration required (Clause 6)

Repaired/adjusted sensor

Entire calibration must be performed – Sizing Calibration, Preliminary Check, Coincidence Error & Flow Rate Limits, Resolution & Accuracy required

Repaired/adjusted volume measurement components

Preliminary Check required

Repaired/adjusted optics

Sizing calibration, Preliminary Check, Coincidence Error Limits, Resolution, Accuracy required

New LPC or no prior 1171 calibration

Entire calibration to be performed – Sizing Calibration, Preliminary Check, Coincidence Error & Flow Rate Limits, Resolution & Accuracy

Sensor cleaned

No action necessary

Cables or peripheral equipment attached

No action necessary

Plumbing lines/connections replaced

No action necessary

Operation performed, no instrument disassembly, sensor or volume measurement system involved

No action necessary

NOTE: Annexes A, B, C and D can be performed by an individual lab or by the manufacturer prior to equipment delivery. Although full ISO 11171 calibration is time consuming, subsequent routine sizing calibrations can be done significantly quicker.