Thermo Scientific SAM12, Manual

Page: 107 / 176

Issue: 1.0 Technical Description - Physics
Thermo Fisher Scientific SAM12 User Manual 6-3
B
sum
Total Average Background Count Rate (cps)
is
the sum of the mean background of all the detectors,
measured over the background update time (
t
B
).
This is a fixed 100 second rolling average in the
SAM. See
Notes regarding Normal Background
Monitoring (page 5-49) .
B
eff
Effective Background while Monitoring (cps)
is
the sum of the mean background of all the detectors,
Bsum, corrected for the effect of attenuation.
T
cal
Calculated Monitoring Time (seconds)
is the
minimum time required to perform a measurement
according to the calculation in
Calculation of the
Monitoring Time (Tcal) (page 6-6) . The specified
alarm level must be achieved with the required
certainty in the Monitoring Time, which will
depend upon a number of user programmable
variables, as well as the Background.
T
mon
Actual Monitoring Time (seconds)
is the actual
time for which Articles are monitored. The
calculated monitoring time (Tcal) is first rounded up
to the nearest whole second. It is then compared
with the user programmed Minimum Monitoring
Time (Tmin) and if Tcal < Tmin then Tmon is
forced to be Tmin, otherwise Tmon = Tcal. If
Tmon > Tmax then a high background condition
exists and normal monitoring is not possible (see
Calculation of the Monitoring Time (Tcal) (page 6-
6)
).
T
min
Minimum Monitoring Time (seconds)
is the
Minimum Time for which articles are monitored,
regardless of the calculated Monitoring Time, see
explanations of Tcal and Tmon above. The
Minimum Monitoring Time is set from in
Params 2
(page 5-10) .
T
max
Maximum Monitoring Time (seconds)
is the
maximum time for which articles are monitored,
regardless of the calculated Monitoring Time, see
explanations of Tcal and Tmon above. The
Maximum Monitoring Time is set in
Params 2
(page 5-10) .
C
Act
C
ontamination Alarm Level (variable unit)
is the
activity level at which the user requires the alarm to
be triggered. The alarm level is set in
Alarms (page
5-12) and the units, e.g. dpm, Bq, nCi, may be
selected in Options (page 5-6) .