VEGA VEGABAR 25 - Manual (Page 4)

4 VEGABAR 25
Product description
1 Product description
1.1 Function and configuration
The VEGABAR 25 process pressure trans-
mitters are efficient instruments for process
pressure measurement. The dry CERTEC
®
metal-capacitive measuring cell is used as a
pressure sensor element. The process pres-
sure causes a capacitance change within the
measuring cell via the diaphragm. This ca-
pacitance change is detected by an ASIC
(application specific integrated circuit) and
converted into a pressure proportional signal
by an integral oscillator with microcomputer.
Precise digital processing of measured data
with highest resolution ensures excellent
technical data.
The oscillator is powered by a separate
VEGA-signal conditioning instrument, a stabi-
lised power supply unit or a PLC (active
input). After the adjustment, a standardised
current signal of 4 … 20 mA is available
which can be displayed (e.g. in PLC-sys-
tems) or further processed.
Four versions are available for adjustment:
- adjustment module directly on VEGABAR
- adjustment module in external housing
(VEGADIS 10)
- via PC with adjustment software (see
manual “VEGA Visual Operating (VVO)“)
- in the control room on the signal condi-
tioning instrument
1.2 Self-monitoring
Important electronic components are
checked for their function, while internal pa-
rameters, such as sensor value, temperature
and operating voltage, are monitored to in-
crease reliability.
If failures 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).