VEGA VEGABAR 41 HART - Manual (Page 4)

4 VEGABAR 41 (HART ® )
Product description
1 Product description
1.1 Function and configuration
VEGABAR 41 is an efficient pressure trans-
mitter with isolating system for process pres-
sure measurement and hydrostatic level
measurement. The hydrostatic pressure of
the products acts on the separating dia-
phragm of the isolating system and is trans-
mitted via the isolating liquid to the metal-
capacitive measuring cell. This capacitance
change is detected by an ASIC (Application
specific integrated circuit) and converted by
the internal electronics with microcontroller
into a pressure-proportional signal. The pre-
cise, high-resolution digital processing of
measurement data ensures perfect technical
data.
Isolating systems are used to protect the
measuring cell against corrosive products or
high temperatures. With the right choice of
isolating liquid and diaphragm material, these
systems can provide a temperature resist-
ance up to 400°C.
The electronics module is powered by a
separate VEGA-signal conditioning instru-
ment, a stabilised power supply unit or a PLC
(active input). After adjustment, a standard
current signal 4 … 20 mA is made available
and can be displayed or (e.g. in PLC-sys-
tems) further processed.
For carrying out adjustment, the following
alternatives are available:
- adjustment module directly on VEGABAR
- adjustment modules in external housing
(VEGADIS 10)
- via PC with adjustment software VEGA
Visual Operating (VVO)
- with HART ® handheld
1.2 Self-monitoring
To improve reliability, the functionality of im-
portant electronic components is continu-
ously checked, and internal parameters such
as sensor value, temperature and operating
voltage are closely monitored.
VEGABAR 41 with the ceramic CERTEC ® -
measuring cell offers the advantage of con-
tinuous self-monitoring. The measuring and
reference capacitances of the measuring cell
constitute a predefined ratio over the entire
measuring range. Any deviation from these
data is a reliable indicator of a malfunction of
the measuring cell.
If errors or malfunctions are detected during
these routines, a fault signal is triggered via
the 4 … 20 mA-output (current jump to
3.6 mA or 22 mA).