Short name:
VTDMA

Full name:
Volatility Tandem Differential Mobility Analyzer

What is being measured:
Particle Volatility

Sampling Protocol:
Online

Manufacturer:
Home-made

Model:
TSI3081, TSI3771, Thermal Denuder 9999

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 VTDMA data that were recorded in scanning mode are analyzed using a custom MATLAB script. Particle size distribution, as a function of time are displayed. Volatility is calculated 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 Thermodenuder 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:
The residence time for particle flow through the thermal denuder is 17s.

Measurement uncertainty:
(a) Local_Time (N/A); (b) Experimental_Time (N/A); (c) Volume_Fraction_Remaining (+/- ?%)

Measurement units:
(a) Local_Time (N/A); (b) Experimental_Time (min); (c) Volume_Fraction_Remaining (N/A)