TSI Instruments 3936 - Page 80

D-2 Model 3936 Scanning Mobility Particle Sizer
TM
(SMPS
TM
) Spectrometer
The following equations are used to calculate mean free path and
gas viscosity:
λ
S
= Actual gas mean free path in meters
λ
R
= Reference gas mean free path in meters (from Properties
dialog)
T
S
= Sample flow temperature in K (from Classifier)
T
R
= Reference temperature in K (from Properties dialog)
P
S
= Sample flow pressure in kPa (from Classifier)
P
R
= Reference pressure in kPa (from Properties dialog)
S = Sutherland Constant (from Properties dialog)
V
R
= Reference gas viscosity in Pa*s (from Properties dialog)
V
S
= Actual gas viscosity in Pa*s