BSA Flow Software Installation and User's Guide - CSI

This is often not necessary in 1D applications, but for 2D and 3D it is
indispensable.
For 1D applications these filters block out background light and are
recommended. With He-Ne lasers use filters for wavelength 623.8 nm (red).
With argon lasers use filters for wavelengths 514.5 nm (green), or 488 nm
(blue) or 476.5 nm (violet).
For 2D applications, the 58N71 2D extension kit is installed in the detector
unit. The kit comprises a colour beam splitter, three 514.5 nm interference
filters, one 488 nm interference filter and a photo-multiplier.
For 3D applications, the 58N72 2D to 3D extension kit is installed. This kit
comprises a colour beam splitter, a 476.5 nm interference filter and a photomultiplier.
If used for 2D or 3D measurement, i.e. with a 58N71 2D extension kit or
(also) a 58N72 3D extension kit installed, the 57X32 filter is required to let
in the green light (wavelength 514.5 nm), while blocking out the light
carrying the other velocity components.
The light from the middle segment of the probe, U3, passes through one (or
two) beam splitters separating out the 488 nm (blue) light, which is directed
to the photo-multiplier tube for the V channel (2D and 3D), and the 476.5
nm (violet) light, which is received by the photo-multiplier tube for the W
channel (3D).
• DualPDA
For U1 and U2 these have a narrow pass band at 514.5 nm wavelength
corresponding to the green argon line. For V1 and V2 the interference filters
pass blue light of wavelength 488 nm.
The 58N82 DualPDA Velocity Extension Kit comprises a fifth interference
filter, with a pass band for the 476.5 nm wavelength.
Calibration The electrical response of a photo-multiplier tube lags slightly relative
system to the light input. This lag depends partly on the individual tube and partly
on the high voltage applied to the photo-multiplier anode. Lack of
knowledge of the exact value of the difference in delay between channels
U1, U2, V1 and V2 could lead to substantial errors in the estimated phase
differences and hence to unreliable calculations of the particle diameter.
BSA Flow Software:Reference guide 7-49