Source container FQG61, FQG62
Hauser
11
Function and system design
Function
Function of the radiation source container
In the FQG61/FQG62 source container, the radioactive source is surrounded by a steel casing filled
with lead which screens off gamma radiation. The radiation can be emitted, almost unattenuated, in
one direction only through a channel (focused narrow beam path). This radiation is used for
radiometric measurement.
Switching the radiation ON and OFF
• By turning the insert 180°, the radiation source is positioned in the radiation emission channel
(radiation is switched on) and removed from the channel (radiation is switched off).
• The current switch position (ON or OFF) is clearly visible from the outside.
• The OFF position can be secured by a cylinder lock or padlock (depending on the version; see
product structure: order code 020, "Version").
• The ON position can be secured by a cylinder lock, a padlock or a locking bolt (depending on the
version; see product structure: order code 020, "Version").
Remote control/remote indication of the switch state
Device versions with a pneumatic drive are available, which enable the radiation to be switched on
and off remotely (product structure: order code 020, "Version K, L, M, N"). These versions have
proximity switches for remote indication of the switch state (ON or OFF).
Fire-resistant version
A fire-resistant version of the radiation source containers is available (product structure: order code
670 "Additional function"). This version has a compensation compartment, which is welded onto the
housing. In the event of a fire, the liquefied lead is collected in the compensation compartment, thus
ensuring the enhanced fire-resistance of the source container.
Attenuation factor and half-
value layers
FQG61
60
Co
FQG61
137
CS
FQG62
60
Co
FQG62
137
CS
Attenuation factor F
S
37
294
181
3100
Number of half-value layers
5.2
8.2
7.5
11.6
The table contains typical values, which do not take into account production-related variations
in the source activity and tolerances of the measuring devices.
Maximum activity of the
radiation source
Source container
60
Co
137
CS
FQG61
max. 0.74 GBq (20 mCi)
max. 18.5 GBq (500 mCi)
FQG62
max. 3.7 GBq (100 mCi)
max. 111.0 GBq (3000 mCi)
L
CAUTION
Maximum admissible activity
‣
The maximum admissible activity can be further restricted by country-specific approvals.
Dose rate diagrams
A dose rate diagram specifies the local dose rate at a specified distance from the surface of the
radiation source container. Examples of dose rate diagrams for FQG61 and FQG62 are presented
below. They apply for a distance of 1 m (3.3 ft)and for selected activities of a
60
Co or
137
Cs radiation
source. All the dose rate diagrams indicated refer to the OFF switch position and to order code 020
"Version", option A "Cylinder lock fixation ON/OFF + cover". The maximum values apply outside the
path of the beam. Dose rate diagrams for other distances and activities are available on request. The
