Comparison for particle number concentration up to 2P/cm3
Project Description
Measurand: Aerosol particle number concentration (PNC)
Range: <0.5 cm-3 up to 2 cm-3 (typical concentration range in cleanrooms)
Secondary parameter: Particle sizes (100 nm, 200 nm, 300 nm, 500 nm, 1 µm, 5 µm, 10µm)
Particle type: solid or nonvolatile-liquid (e.g. PSL, salt, lactose etc.)
Round robin interlaboratory test:
Each participant owns a reference or primary standard, and provides one OPC to be shipped in turn to all participants as transfer standard.
Each participant generates at least one type of calibration aerosol at his own facility and simultaneously records the PNC of all provided counters. The PNC measured by the reference or primary standard is not communicated to the other participants, but only to the organiser after all measurements have been completed.
Final Report 2020-02-17
METAS, DFM and AIST participated in the intercompasiron by providing a Solair 1100 (Lighthouse Worldwide Solutions), an Abakus (Klotz GmbH) and a KC-31 (Rion) optical particle couter (OPC), respectively, as transfer standard. The OPCs were sent in turn to METAS, DFM, AIST and back to METAS for a round robin test. Each participant generated calibration aerosols using his own custom-built facility and determined the measurement efficiency of all three OPCs. METAS and DFM generated PSL (polystyrene latex) aerosols in the size range 300 nm - 5 μm at concentrations of about 1-2 cm-3 while AIST generated lactose monohydrate and NaCl (sodium chloride) aerosols with PSL optical equivalent diameter in the range 500 nm - 5 μm at concentrations <1 cm-3. The reference value was calculated for each OPC separately as a weighted average of the values (i.e. measurement efficiencies) determined experimentally by each participant. The individual measurements for the transfer standards at each laboratory are in good agreement with the reference value, typically within 7 %, which supports the applied national primary methods of measurement.
Progress Report 2019-02-26
METAS, DFM and AIST participated in the intercompasiron by providing a Solair 1100 (Lighthouse Worldwide Solutions), an Abakus (Klotz GmbH) and a KC-31 (Rion) optical particle couter (OPC), respectively, as transfer standard. The OPCs were sent in turn to METAS, DFM, AIST and back to METAS for a round robin test. Each participant generated calibration aerosols using his own custom-built facility and determined the measurement efficiency of all three OPCs. METAS and DFM generated PSL (polystyrene latex) aerosols in the size range 300 nm - 5 μm at a concentration of 1 cm-3 while AIST generated lactose monohydrate and NaCl (sodium chloride) aerosols with PSL optical equivalent diameter in the range 500 nm - 5 μm at a concentration <1 cm-3. The reference value was calculated for each OPC separately as a weighted average of the values (measurement efficiencies) determined experimentally by each participant. Preliminary data analysis shows good agreement between participants with the deviation between measured and reference values lying typically well within the reported measurement uncertainties.