Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS)


Operated By: 

HR-AMS instrument installed on the NASA DC-8 for ATom-1

Principle: The CU aircraft version of the Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) detects non-refractory submicron aerosol composition by impaction on a vaporizer at 600°C, followed by electron ionization and time-of-flight mass spectral analysis. Size-resolved composition can be quantified by measuring the arrival times of the aerosol at the vaporizer.

Aircraft Operation: (1 min cycles, can be adjusted to meet mission goals):
46 s total concentration measurements (1 s resolution)
5 s size distribution measurements
9 s Background + Overhead

Data Products: 
Aerosol Mass Concentrations:
Organic aerosol (OA) , SO4, NO3, NH4, Chloride
OA Chemical Markers: f44 (Secondary OA), f57 (hydrocarbon-like OA), f60 (biomass burning OA), f82 (isoprene epoxide-SOA)
All products are available in real-time
More advanced products:
- O/C, H/C, OA/OC
- Particle organic nitrates (RONO2)
- Ammonium Balance, estimated pH
- OA components by positive matrix factorization

Detection Limits (1s, ng sm-3), (1 min, ng sm-3):
Sulfate: 50, 15
Nitrate: 30, 10
Ammonium: 10, 3
Chloride: 40, 12
OA: 500, 130
For detailed OA analysis, longer averaging (3-30 s, depending on OA concentration) is needed. A 1 min product is hence available as well.

Instrument Type: