VEGA VEGAMET 307_308 - Manual (Page 2)

Application
These signal conditioning instruments VEGAMET
307 / 308 are used for level proportional output and
indication of levels (continuous level measure-
ment). The VEGAMET 308 is additionally equipped with
an integral level switch with adjustable switching
hysteresis. Therefore level dependent switching
functions are possible.
The VEGAMET 307 consists of:
• plastic housing with pluggable multipoint connec-
tor (series 300)
• electronics
• front panel with
- analog indicating meter
- mains control lamp
- potentiometer for empty adjustment
- potentiometer for full adjustment
- change-over switch for current output range
0 … 20 mA or 4 … 20 mA.
The VEGAMET 308 consists of:
• as VEGAMET 307
• however additional adjustment elements for the
level switch:
- 2 pressure keys and 2 potentiometers for
adjustment of the switch points
- relay control lamp
- A/B-switch
A measuring system consists of:
• signal conditioning instrument VEGAMET 307 or
VEGAMET 308
• capacitive electrode with oscillator
or
• pressure sensor with oscillator
Additional indicators and auxiliary level switches
can be connected to the current and voltage
outputs.
Level measurement with capacitive electrodes
Electrode, product and vessel wall, or electrode
and product form a capacitor. The capacitance
increases with increasing level.
In either case the oscillator converts this capaci-
tance change into a level proportional measuring
signal. This signal is fed to the VEGAMET 307 or
308 for signal conditioning.
Level measurement with pressure sensors
The diaphragm of the pressure sensor converts the
hydrostatic pressure of the product into a linear
movement. This movement is transmitted to the
plunger-type capacitor. The level of the product
therefore changes the capacitance.
Configuration
Function
2 VEGAMET 307 / 308