| VEGAPULS generates short microwave pulses which are emitted from the antenna to the product. The microwaves travel at light velocity and the sensor detects the time taken for the pulses to be reflected from the product's surface. The distance, or product level, is proportional to the refection time, given by:
t = 2Lc where:
L = distance
c = velocity of light
Microwaves, being electromagnetic waves, are propagated similarly to optical radiation with light velocity. Unlike sound waves, microwaves require no transmission medium and VEGAPULS can operate in vacuum and positive pressure conditions.
Changes in vessel pressure, between vacuum and 50 bar, have virtually no influence on the reflection time and therefore the resultant level measurement. Likewise with temperature changes, large variations can be tolerated with no significant effect on output.
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