1. WBEA Passive Sampler Validation Study for NH3 and HNO3 Operation of the dual-channel Annular Denuder System (ADS)

2. ADS Pump Operation Pump control settings at front panel of ADS pump box

3. ADS Channel Flow Control Connect brass tee with quick-connect fitting to port labeled Vacuum 1 (not as depicted!). Vacuum 2 will be closed per front panel setting. Needle valves at each of the two tee branches allow fine adjustment of sample flow through each ADS channel. Each channel’s total sample volume is measured by a dry test meter (DTM). Connect black sample tubing from each channel (left hand side in photo) via quick- connect adapter to each needle valve and make note of the corresponding ADS channel. Back panel of ADS pump module

4. ADS Monthly Sample Volume Before sample start, use BIOS Drycal (or similar flow reference) and set each channel’s ambient flow rate to 2.0 lpm by adjusting the needle valve. Check nominal 2.0 lpm after initial setting. Read displayed value of each channel’s dry test meter (DTM) before connecting it to the needle valve. Record the DTM readings and start time. Perform weekly readings (next slide). At end of 1 month’s sampling, record the DTM readings and stop time.

5. Weekly Sample Flow Checks 1.Elapsed timers (only channel 1 is active) 2.Timer reset buttons (reset monthly) 3.Vacuum gauge (indicates loaded filter) 4.Circuit breakers 5.Pump controller from slide #2 6.Volumetric flow control (set to >4 Lpm) 7.Display of actual flow rate in Lpm (channel 1 only, since OUT2 = Off, see slide #2) 8.Read/Set point toggle switch (should always be in “Read” mode) 9.Radiant shield for accurate T measurement needed for MFC density correction On a weekly basis, read each channel’s sample volume displayed on DTM units and note in log with reading date/time and displayed flow rate (# 7 above).