Instrument - Hygroscopicity Tandem Differential Mobility Analyzer
Short name:
HTDMA
Full name:
Hygroscopicity Tandem Differential Mobility Analyzer
What is being measured:
Particle Hygroscopicity
Sampling Protocol:
Online
Manufacturer:
Home-made
Model:
TSI3081, TSI3771
Instrument year
:
2006
Data recording software:
Labview Program
Data analysis software:
Custom MATLAB script
Raw data time resolution:
1s
Analysis data averaging:
180s to 600s
Detection limit:
N/A
Sensitivity to temperature (and correction method, if applicable):
:
N/A
Sensitivity to relative humidity (and correction method, if applicable):
:
N/A
Sampling method:
Direct gas sampling
Sample preparation method:
None
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
Tubing material:
Copper
Chemical identification method:
None
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.
Quantification method:
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.
Calibration method:
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:
No estimate
Calibration schedule:
Annually
Uncertainty estimation method:
Duplication of the same experimental conditions.
Known interferences:
N/A
Link to supplemental information:
N/A
Additional notes:
Measurement uncertainty:
(a) Local_Time (N/A); (b) Experimental_Time (N/A); (c) Growth_Factor (+/- ?%)
Measurement units:
(a) Local_Time (N/A); (b) Experimental_Time (min); (c) Growth_Factor (N/A)