Model 3000 Survey meter User’s Manual Section 7
Ludlum Measurements, Inc. Page 7-1 April 2021
Advanced Features
Dead Time Correction
All pulse counting detectors have a “dead time” in which the detector is
unable to register another event. In relatively low fields this is not an issue.
However, as the field strength approaches the high end of the detector’s
range, dead time causes the pulse rate to become non-linear with respect to
the real radiation field. Dead time correction is used to linearize the
measurements, allowing a wider linear response range for a given detector.
This instrument uses a second order dead time correction using the equation
where
and
are the dead time correction coefficients,
is
the measured count rate, and
is the corrected rate.
Dead time correction coefficients are configured through the device setup
menu or through Lumic Calibration software. Lumic Calibration software also
includes a wizard that will automate finding and setting the correct
coefficients.
is represented in micro seconds (µs) on the device setup menu and in
the software. The equation must be calculated in terms of seconds (s) and
must be scaled appropriately.
has more complex units and are not
shown. However, the representation of the coefficient on the setup menu
and in software do not require scaling.
Note:
Setting the
to zero will disable the second order correction,
while setting
to zero will disable both, regardless of the value
of
.
To Next Page
Loading...
