BERTHOLD TECHNOLOGIES LB 480, Руководство пользователя

Страница: 95 / 450

SENSseries LB 480 Level measurement
BERTHOLD TECHNOLOGIES GmbH & Co. KG
1 – 95
Volume 1 7 Functional Safety
1
7.5.1.2
Level measurement
The measuring system consists of a detector and a radiation source.
Both the detector and the radiation source may be designed
rod-shaped or point-shaped. These are mechanically positioned so
that the desired measuring range can be covered. The safety func-
tion is to monitor the fill level of the product to be monitored within
the measuring range.
Principle of measurement
As long as the level does not reach the area of the beam path, the
radiation arrives unhindered at the detector. Once the level is within
the measuring range, part of the radiation is absorbed. This reduced
radiation intensity is indicated at the detector as rising level. The
more the level rises, the more the radiation is reduced, which the
detector signals as a continuous level increase from 0 to 100%.
The level change from 0 ... 100% is represented by the analog cur-
rent output 4 ... 20mA.
Signal
"0%"
Signal
"70%"
Shielding with
radiation source
Shielding with
radiation source
Radiation path
Radiation in
part
absorbed by
product
Product below
the beam path
Container
Container
Detector
Detector