KROHNE H250 M9 Safet V2 EN - Manual (Page 5)

DESCRIPTION
3
5
H250 M9
www.krohne.com 06/2013 - 4000656702 MA H250-M9 SIL R03
Description
3.1 Functional principle
The flowmeter operates in accordance with the float measuring principle.
A metal cone is installed in the measuring unit H250, in which a suitably shaped float can move
freely up and down.
The flowmeter is inserted into a vertical pipeline and the medium flows through it from bottom to
top.
The guided float adjusts itself so that the buoyancy force A acting on it, the form drag W, the
weight G and the spring load S are in equilibrium (G + S = A + W).
An annular gap results which width depends on the current flow rate.
The height of the float in the measuring unit, which depends on the float, is transmitted by a
magnetic coupling and displayed on a scale.
Strong deflecting magnetic fields can lead to deviations in the measured value.
Figure 3-1: Functional principle
MA_H250_M9_SIL2_R03_en_656702_PRT.book Page 5 Wednesday, June 26, 2013 9:08 AM