Short name:
Q-ACSM

Full name:
Quadrupole-Aerosol Chemical Speciation Monitor

What is being measured:

Sampling Protocol:
Online

Manufacturer:
Aerodyne

Model:
0

Instrument year :
None specified

Data recording software:
ACSM-DAQ

Data analysis software:
Igor

Raw data time resolution:
1 minute

Analysis data averaging:
10-15 minutes (depends on user)

Detection limit:
Organic: 0.3 ug/m3. Sulfate: 0.04 ug/m3. Nitrate: 0.02 ug/m3. NH4: 0.5 ug/m3. Chloride: 0.02 ug/m3

Sensitivity to temperature (and correction method, if applicable): :

Sensitivity to relative humidity (and correction method, if applicable): :

Sampling method:
Direct sampling

Sample preparation method:

Sample residence time (chamber to instrument) (seconds):

Length of tubing (cm):
0.02

Instrument flow rate:
0.085

Tubing inner diameter:

Tubing material:
Copper

Chemical identification method:
The instrument operates by sampling air into a high vacuum system through a particle aerodynamic lens. The particle lens focuses submicron aerosol (~40-1000 nm aerodynamic diameter) into a narrow beam which is directed to a resistively heated particle vaporizer, typically operated at 600°C, mounted inside the ionization chamber of a mass spectrometer where non-refractory components in/on the particle flash vaporize on impact. The vaporized constituents are ionized by electron impact then analyzed with a quadrupole mass spectrometer which reports aerosol mass spectra (<200 amu). These spectra are used to extract the chemically speciated aerosol mass loadings.

Data analysis method:
The chemically speciated aerosol mass loadings are corrected for relative ionization efficiency and collection efficiency using the ACSM Local package on Igor Pro. Timeseries plots of species concentrations, triangle plots of oxidation states, as well as several other plots can be created. Depending on the user, the data can be averaged to 10 mins instead of the 1 min raw data to reduce noise.

Quantification method:

Calibration method:
Single-scan mode and jump-mode calibration

Calibration drift estimate:
Low (on the order of weeks)

Calibration schedule:
As Needed

Uncertainty estimation method:
Ammonium nitrate concentrations are measured by the ACSM and CPC and compared. The average difference is 10%.

Known interferences:

Link to supplemental information:

Additional notes:

Measurement uncertainty:

Measurement units: