VEGA SOLITRAC 31 4 … 20 mA_HART - four-wire With SIL qualification - Manual (Page 8)

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3 Product description
SOLITRAC 31 • 4 … 20 mA/HART - four-wire
43387-EN-131119
•
Modification status electronics from -07
The instrument is available in different electronics versions. Each ver-
sion can be identified via the product code on the type label:
•
Standard electronics type PT30E-XX
The scope of delivery encompasses:
•
Radiation-based sensor
•
Mounting accessory
•
Documentation
– this operating instructions manual
– Safety Manual (SIL) PROTRAC series 30 (Document-ID 42961)
– Operating instructions manual "Display and adjustment mod-
ule" (optional)
– Ex-specific "Safety instructions" (with Ex versions)
– if necessary, further certificates
3.2 Principle of operation
The instrument is suitable for applications in liquids and bulk solids in
vessels under difficult process conditions. There are application pos-
sibilities in nearly all areas of industry.
The level is detected contactlessly right through the vessel wall.
Neither a process fitting nor a vessel opening are required. The instru-
ment is thus ideal for retro installation.
In radiation-based measurement, a Caesium-137 or Cobalt-60 iso-
tope emits focussed gamma rays that are attenuated when penetrat-
ing the vessel wall and the medium. The PVT detector on the opposite
side of the tank receives the radiation, whose strength is dependent
on the level. The measuring principle has proven to be very reliable
in conjunction with extreme process conditions because it measures
contactlessly from outside through the vessel wall. The measuring
system ensures maximum safety, reliability and plant availability,
independently of the medium and its properties.
3.3 System limitations
There are several measuring principle-specific factors which can influ-
ence the measuring result. Keep these factors in mind in order to fully
utilize the capabilities of the instrument with respect to measurement
certainty and reproducibility.
The implemented radioactive isotope and its activity must be selected
according to the properties of the vessel and the medium. The neces-
sary radioactive activity must be calculated on the basis of the plant
data.
To this end, make use of our planning service for an optimum layout of
the measurement and selection of the isotope. This applies particu-
larly to SIL applications.
Electronics versions
Scope of delivery
Application area
Functional principle
Activity of the source