NOMEX
Operating Manual - NOMEX Multimeter Setup
D909.131.00/02 en
45
6.3.1 Sensitivity Mode
The following settings are available in the
Sensitivity Mode
menu:
Normal
The sensitivity mode
Normal
is the stan-
dard measuring mode of the NOMEX
multimeter.
High
The sensitivity mode
High
is intended for
measuring low dose rates (< 5 µGy/s)
at direct current/high frequency tube volt-
ages (DC/HF). The recommended mini-
mum measuring time is 5 seconds.
In this mode the measurement sampling and the
start delay in submenu
Timer
cannot be config-
ured.
In addition, the following measuring quantities are
not available:
– Mean dose rate after the measurement
1)
– Dose per pulse
– Frequency
– Pulses.
In the sensitivity mode
High
the measured values
of kVp
max
, kVp
mean
and PPV are identical. The time
resolution is 0.5 sec.
Heavily Filtered
The sensitivity mode
Heavily Filtered
is intended for measuring low dose
rates (< 5 µGy/s) at direct current/
high frequency tube voltages (DC/HF)
and heavily filtered radiation qualities
(TF > 1 mm Cu). The recommended min-
imum measuring time is 5 seconds.
In this mode, the following measurement settings
in the submenus
Timer
and
Ranging
cannot be
configured:
– Measurement sampling
– Start delay
– kV range
– TF range.
In the sensitivity mode
Heavily Filtered
only the
following measuring quantities are available:
– Dose rate during the measurement
1)
– Dose
– Exposure time.
In this mode, the time resolution is 0.5 sec.
The sensitivity mode
Heavily Filtered
makes
sense if you intend, for instance, to measure the
dose rate in fluoroscopy behind an absorber with
1.5 mm Cu + 25 mm Al.
For MAM applications, it is not possible to select
the sensitivity modes
High
and
Heavily Filtered
.
1 )
In both sensitivity modes "High" and "Heavily Filtered", the current dose rate will be displayed during the measure-
ment
After the measurement,
"---"
will be displayed instead of the mean dose rate because of the reduced time resolu-
tion of 0.5 seconds.
