The sampling funnel was 3D printed from PLA (1.75 mm filament) by a RAISE3D Pro2 Printer (3DGBIRE). The funnel was 150 mm wide, 90 mm deep with 3 ports at the neck for sampling aerosol into up to three aerosol instruments (some combination of APSs and OPSs). All tubing was conductive silicone and 130 cm in length (TSI Inc., product number 3001788, inner diameter 0.19 inch, outer diameter 0.375 inch).