7
UK
6 Function
6.1 Measuring principle
fig. 5-1
fig. 5-2
D
The unit operates to the principle of guided wave radar. It measures the level
using electromagnetic pulses in the nanosecond range.
The pulses are transmitted by the sensor head and guided along the rod (fig.
5-1). When they hit the medium to be detected they are reflected and guided back
to the sensor (fig. 5-2). The time between transmitting and receiving the pulse
directly relates to the travelled distance (D) and the current level. The reference for
distance measurement is the lower edge of the process connection.
The signal quality may be affected with:
-intensely absorbing surfaces (e.g. strong foam formation)
-intensely bubbling surfaces
-media which are very inhomogeneous, separate from each other thus
forming separation layers (e.g. oil layer on water)
►
Check the function by an application test
6.2 Other features of the unit
•
Hygienic approvals / conformities (→ Technical data sheet)
•
For CIP / SIP applications: High temperature range (→ Technical data sheet)
• Special operating mode for media with increased foam formation
