VEGA VEGABAR 86 Modbus and Levelmaster protocol - Operating Instructions - Manual (Page 9)

9
3 Product description
VEGABAR 86 • Modbus and Levelmaster protocol
46296-EN-131107
The VEGABAR 86 is a suspension pressure transmitter for level
measurement in wells, basins and open vessels. Its great flexibility
through different cable and tube versions allows the instrument to be
used in many different applications.
Measured products are liquids.
Depending on the instrument version and measurement setup, meas-
ured products can be also viscous or contain abrasive substances.
Sensor element is the CERTEC ® measuring cell with robust ceramic
diaphragm. The process pressure deflects the ceramic diaphragm
and causes a capacitance change in the measuring cell. This capaci-
tance change is converted into an electrical signal and outputted as
measured value via the output signal.
The CERTEC
® measuring cell has also an integrated temperature
sensor. The temperature value is outputted through:
•
The display and adjustment module
•
The current output
•
The digital signal output
The measuring cell design depends on the selected pressure type.
Relative pressure: the measuring cell is open to atmosphere. The
ambient pressure is detected in the measuring cell and compensated.
It thus has no influence on the measured value.
Absolute pressure: the measuring cell is evacuated and encapsu-
lated. The ambient pressure is not compensated and does hence
influence the measured value.
Relative pressure, climate-compensated: the measuring cell is
evacuated and encapsulated. The ambient pressure is detected
through a reference sensor in the electronics and compensated. It
thus has no influence on the measured value.
The following illustration shows the installation of the CERTEC ®
measuring cell in the transmitter as well as the sealing concept.
1
2
3
4
5
Fig. 3: Front-flush installation of the CERTEC ® measuring cell with double seal
1 Housing, transmitter
2 Measuring cell
3 Lateral seal for measuring cell
4 Additional, front seal for measuring cell
5 Diaphragm
Application area
Measured products
Measuring system
Pressure types
Seal concept