Instrument - Hygroscopicity Tandem Differential Mobility Analyzer
Hygroscopicity Tandem Differential Mobility Analyzer
What is being measured:
Data recording software:
Data analysis software:
Custom MATLAB script
Raw data time resolution:
Analysis data averaging:
180s to 600s
Sensitivity to temperature (and correction method, if applicable):
Sensitivity to relative humidity (and correction method, if applicable):
Direct gas sampling
Sample preparation method:
Sample residence time (chamber to instrument) (seconds):
Length of tubing (cm):
Instrument flow rate:
Sheath 2.5 lpm; Main 0.25 lpm
Tubing inner diameter:
1/4'' OD; 0.152'' ID
Chemical identification method:
Data analysis method:
The HTDMA data that were recorded in scanning mode are analyzed using a custom MATLAB script. Particle size distribution, as a function of time are displayed. Hygroscopicity is indicated by the size difference of the selected particles after the 1st and 2nd DMA.
Signal strength is converted to partial number/size distribution by designed transfer functions. Concentration is not important for this instrument but the sizes selected by the two DMAs.
Atomizing Ammonium Sulfate Aerosol into the system with the particle growing device off and check the scanning size with the first DMA under different measuring modes.
Calibration drift estimate:
Uncertainty estimation method:
Duplication of the same experimental conditions.
Link to supplemental information:
(a) Local_Time (N/A); (b) Experimental_Time (N/A); (c) Growth_Factor (+/- ?%)
(a) Local_Time (N/A); (b) Experimental_Time (min); (c) Growth_Factor (N/A)