RTI Barracuda User Manual

4. Measurement Principles & Theory
Update Modes
Barracuda & QABrowser Reference Manual
2012-10/4.3A
96
Update Modes4.3
As described under Measurement Type
Settings and seen in the figure to the left,
the following four update modes are
available:
· After exp., the QABrowser receives a new value when the exposure terminates.
This means when the output goes under the trig level and stays there at least the
time set by Post Delay under Settings | Barracuda. Reset time is one second.
· Continuous, the Barracuda is continuously sending data as long as radiation is
detected. Displays in the QABrowser are updated about every four seconds.
Typically used for Fluoroscopy. Reset time is one second.
· Timed, the user sets a measurement time. The user then starts the measurement
and the Barracuda will measure all radiation received during the measurement
time, without any trig levels or background compensation. When the time has
passed, a reading will be presented. It has a long reset time for increased
accuracy, which varies with the sensitivity, as seen in the table below.
· Free run, the Barracuda will continuously measure the radiation without any trig
levels or background compensations. No applications are available when using
this mode. The mode has a feature called moving average which calculates the
average of the measured values during a defined time, to increase accuracy by
lowering the time resolution. This function gives a larger stability to the
measurements. Free run also has a long reset time for increased accuracy, see
the table below.
Default value is set according to selected type of measurement and this parameter
normally never needs to be manually changed, unless really low-level measurements
are to be accomplished.
However, to measure on real low-level signals the Timed or Free run update mode
may be used, see topic Very Low Dose Rate Measurements with EMM-BiasW .
Update mode
Auto
reset
Reset
time
(s)
Sample
time
(ms)
Min. WF
rec. time
(s)
Max. WF
rec. time
(s)
After Exposure
–
1
0.5-64
0.32 1
40
Timed (Low/High sens.)
–
4
0.5-64
0.32 1
40
Timed (Very High sens.)
–
30
20-2560
13
2000
Continuous
Yes
1
0.5-64
0.32 1
40
Free run (Low/High sens.)
–
4
0.5-64
0.32 1
40
Free run (Very High sens.)
–
30
20-2560
13
2000
Note 1: If your detector is slower (typically ion chambers) the minimum WF recording time may
95
110

RTI Barracuda Specifications

General

Brand	RTI
Model	Barracuda
Category	Medical Equipment
Language	English