6
2 Product description
FIBERTRAC 31 • Four-wire 4 … 20 mA/HART
62067-EN-211203
The level is detected contactlessly right through the vessel wall.
Neitheraprocessttingnoravesselopeningarerequired.Theinstru-
ment is thus ideal for retro installation.
Inradiometricmeasurement,aCaesium-137orCobalt-60isotope
emits focussed gamma rays that are attenuated when penetrating
the vessel wall and the medium. The PVT detector on the opposite
sideofthetankreceivestheradiation,whosestrengthisdependent
on the level. The measuring principle has proven to be very reliable
inconjunctionwithextremeprocessconditionsbecauseitmeasures
contactlessly from outside through the vessel wall. The measuring
systemensuresmaximumsafety,reliabilityandplantavailability,
independently of the medium and its properties.
2.3 Corresponding source container
A radioactive isotope in a suitable source holder is the prerequisite for
a radiometric measurement setup.
The handling of radioactive substances is regulated by law. The radia-
tion protection rules of the country in which the system is operated
applyrstandforemost.
InGermany,forexample,thecurrentradiationprotectionordinance
(StrlSchV) based on the Atomic Energy Law (AtG) applies.
The following points are important for measurement with radiometric
methods:
A handling permit is required for operation of a system using gamma
rays.Thispermitisissuedbytherespectivegovernmentoceorthe
responsibleauthority(inGermany,forexample,ocesforenviron-
mentalprotection,tradesupervisoryboards,etc.)
Youcanndfurtherinstructionsintheoperatinginstructionsmanual
of the source container.
Whenhandlingradioactivesources,unnecessaryradiationexposure
mustbeavoided.Anunavoidableradiationexposuremustbekeptas
low as possible. Take note of the following three important measures:
1 2 3
Fig. 2: Measures for protection against radioactive radiation
1 Shielding
2 Time
3 Distance
Functional principle
Handling permit
General instructions for
radiation protection