AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Traceable Calibration of Detection Efficiencies of Optical Particle Counters using Inkjet Aerosol Generator
KENJIRO IIDA, Kensei Ehara, Hiromu Sakurai, AIST
Abstract Number: 377 Working Group: Instrumentation and Methods
Abstract National institute of advanced industrial science and technology (AIST), Japan, launched a calibration service for evaluating the counting efficiencies of optical particles counters (OPCs). The values are evaluated using a monodisperse aerosol generator which can precisely control the particle generation rates. The device is called AIST-inkjet aerosol generator (AIST-IAG) which is the primary standard for particle count rates of OPCs at AIST. In the menu for the calibration serve, particle count rates range from 10 /s to 100 /s, particle diameter ranges from 0.5 um to 10 um, sampling flowrates of OPC, Q, range from 0.3 L/min to 30 L/min, and particle materials are sodium chloride, ammonium sulfate, and water soluble ionic liquid. Aerosol flowrate of AIST-IAG cannot exceed 1 L/min; therefore, when the value of Q is greater than 1 L/min, clean sheath-air is added at a sampling inlet to complement the value of Q. The value of Q can be measured traceably upon request to express the values of E in terms of particle number concentration. For example, the ranges of concentrations are 0.02-0.2 /cm3 and 2-20 /cm3 when the value of Q are 30 L/min and 0.3 L/min, respectively. In this presentation calibration results for four OPCs whose sampling flowrates are 0.3, 0.5, 2.83, and 28.3 L/min. The expanded uncertainties of the counting efficiencies, U(k=2), were evaluated in the plateau region of the size-dependent counting efficiency curve when the particle generation rate of the AIST-IAG was fixed at 100 /s. The values of U(k=2) based on particle count rates ranged from 0.0025 to 0.0027. In terms of the particle number concentration the values ranged from 0.0044 to 0.0046. The results demonstrates that the AIST-IAG can calibrate OPCs accurately. This calibration method can potentially become an alternative to the calibration methods documented in ISO 21501-4 or JIS B 9921.