KROHNE H250 M8-M9-M10 EN - Manual (Page 64)

8
TECHNICAL DATA
64
H250
www.krohne.com 04/2011 - 4000269302 MA H250-R02 en
Technical data
8.1 Operating principle
The flowmeter H250 operates on the float measuring principle. The measuring unit consists of a
metal cone in which a float can move freely up and down. The medium flows through the
flowmeter from bottom to top. The float adjusts itself so that the buoyancy force B, acting on it,
the form drag D and its weight W are in equilibrium: W = B + D.
For indicators M9 and M8MG 1 the flow-dependent height of the float in the measuring unit is
transmitted by means of a magnetic coupling and displayed on a scale. For indicators M10 and
M8EG 2 the flow-dependent height of the float in the measuring unit is transmitted to the
electronic display by magnetic field sensors S1 and S2.
The flowmeters operate according to a modified float measuring principle. The guided float
adjusts itself so that the flow force acting on it is in equilibrium with the opposing spring force.
The flow-dependent position of the float in the measuring unit is displayed on a scale by means
of a magnetic coupling.
Figure 8-1: Operating principle
1 Indication principle M9 and M8MG
2 Indication principle M10 and M8EG
Operating principle of H250H and H250U
Figure 8-2: Operating principle H250H and H250U
1 H250H - horizontal flow direction
2 H250U - flow direction from top to bottom
INFORMATION!
Flowmeters H250H and H250U only work in conjunction with indicator M9.
MA_H250_R02_en_269302_PRT.book Page 64 Tuesday, April 12, 2011 10:17 AM