BS ISO 27891:2015

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Calibration using reference instruments - General
  principles
6 Calibration using an FCAE as reference instrument
7 Calibration using a CPC as reference instrument
8 Reporting of results
Annex A (informative) - CPC performance characteristics
Annex B (informative) - Effect of particle surface
        properties on the CPC detection efficiency
Annex C (informative) - Example calibration certificates
Annex D (normative) - Calculation of the CPC detection
        efficiency
Annex E (informative) - Traceability diagram
Annex F (informative) - Diluters
Annex G (normative) - Evaluation of the concentration
        bias correction factor between the inlets of the
        reference instrument and test CPC
Annex H (informative) - Extension of calibration range
        to lower concentrations
Annex I (informative) - Example of a detection efficiency
        measurement
Annex J (normative) - Volumetric flow rate calibration
Annex K (normative) - Testing the charge conditioner and
        the DEMC at maximum particle number concentration
Annex L (informative) - A recommended data recording
        method when using a reference FCAE
Annex M (informative) - Uncertainty of detection efficiency
        due to particle size uncertainty
Annex N (informative) - Application of calibration results
Bibliography

Defines methods to determine the detection efficiency of condensation particle counters (CPC[s]) at particle number concentrations ranging between 1 cm[-3] and 10[5] cm[-3], together with the associated measurement uncertainty.

This International Standard describes methods to determine the detection efficiency of condensation particle counters (CPCs) at particle number concentrations ranging between 1cm^-3 and 10⁵cm^-3, together with the associated measurement uncertainty. In general, the detection efficiency will depend on the particle number concentration, the particle size, and the particle composition. The particle sizes covered by the methods described in this International Standard range from approximately 5nm to 1000nm.

The methods can therefore be used both to determine a CPC calibration factor to be applied across the range of larger particle sizes where the detection efficiency is relatively constant (the plateau efficiency), and to characterize the drop in CPC detection efficiency at small particle sizes, near the lower detection limit. These parameters are described in more detail in AnnexA.

The methods are suitable for CPCs whose inlet flows are between approximately 0,1l/min and 5l/min.

This International Standard describes a method for estimating the uncertainty of a CPC calibration performed according to this International Standard.