Canberra Lynx DSA, Руководство пользователя

Страница: 57 / 235

Lynx Genie 2000 Acquisition Window Adjust
Lynx DSA User's Manual - 9240227J 47
Gain Spacing
Sets the spacing (in channels) between the upper and lower sampling windows. For
broad peaks, the spacing should be set so that the windows’ edges are not on the flat
part of the peak.
Gain Mode
Sets the Gain Stabilization mode to Off , On , or Hold .
•
Off disables spectrum stabilization and sets the correction adjustment to the
system gain back to zero.
•
On enables the spectrum stabilization by allowing the Stabilizer to
continuously monitor the incoming data and compare its rate against a pre-
established reference, adjusting the system gain as necessary to maintain a
stable ratio.
•
Hold suspends the spectrum stabilization and retains the current correction to
the system gain until the Stabilizer is switched to either Off or On . Switching
from Hold to On resumes stabilization; switching from Hold to Off disables
stabilization and resets the current correction.
Gain Ratio
The Gain Ratio can be manually entered when the Ratio Mode is set to Manual , or
automatically calculated by the Lynx when the Ratio Mode is set to Auto .
The Gain ratio value is interpreted by the stabilizer as the ratio to maintain between
the two windows (ratio = upper window / lower window). For instance, a value of
1.000 would be appropriate for a pure Gaussian peak.
Reset
During the normal course of operation, if the stabilization algorithm attempts to set a
correction value that is beyond its allowable range ( ±10% for NaI mode or ±1 % for
Ge mode), the Lynx will assert an over-range or under-range fault. Additionally, the
Lynx will switch the stabilizer mode from On to Hold .
Under normal temperature variations, the amount of gain compensation necessary to
maintain a stable storage location should be well within the allowed stabilization
range. An over-range or under-range fault may be an indication of faulty electronics
and thus requires operator intervention. The fault will remain asserted until (a) the
operator acknowledges the fault by pressing the Reset, or (b) the Stabilizer Mode is
turned to Off.
In Genie, a Status/Update must be performed to clear the fault within the application.
Gain Rate Div
The Gain Rate Divider is a factor by which the level of correction applied to the
system gain is reduced by. This value in effect determines the aggressiveness of the
stabilization algorithm. The algorithm becomes less aggressive as the correction
divider is increased.