Gentec-EO Beamage-3.0 User Manual
Page 70
Beamage-3.0 User Manual Revision 6.0
69
̃
∑ ( ̅
̅
)
̃
∑ ( ̅
̅
)( ̅
̅
)
In the beam axis coordinate system (X,Y,Z), the beam positional stability values in the azimuth direction
(X) and perpendicularly to the azimuth direction (Y), which are 4 times the standard deviations of all
computed centroid values, are given by the following equations:
( )
( )
The overall positional stability is given by:
( ) √
In the previous 3 equations, the standard deviations are defined by the following equations:
√
∑ ̅
√
∑ ̅
√
∑ ̅
̅
̅
and
̅
are derived from
̅
and
̅
by transformation of coordinates. (X’,Y’,Z’) is the usual or
laboratory coordinate system and (X,Y,Z) is the beam axis coordinate system.
The RMS standard deviation value of the centroid position, which is not an ISO standard, is given by the
following equation:
√(
∑
)
Where
are relative values.