KROHNE BM 26 BASIC_ADVANCED EN - Manual (Page 46)

8
TECHNICAL DATA
46
BM 26 BASIC/ADVANCED
www.krohne.com 10/2012 - 4000347004 - HB BM26 Basic/Adv R04 en
8.1 Measuring principle
The device operates on the principle of communicating tubes. The measuring chamber is
connected adjacent to the tank. The process conditions in the measuring chamber are the same
as those of the tank.
A float is in the measuring chamber. The float contains magnets that rotate the flaps in the
indicator column and operate the optional limit switches and analog transmitter on the side of
the measuring chamber. The position of the magnets does not correspond to the level of liquid
so the scale is offset at the factory to take into account this difference. The offset of the magnets
depends on the liquid density. Refer to the illustration that follows:
Magnet offset
Figure 8-1: Magnet offset
1 True level of the liquid
2 Top of the float magnet (which corresponds to the level shown on the indicator column)
3 Difference (offset) between the true level of the liquid and the top of the float magnet (depends on the liquid density)
4 Indicator column of yellow/black rotating flaps (with the optional scale)