Micropilot M FMR 240 with Foundation Fieldbus
Mounting
E Hauser
17
Measuring conditions
L00-FMR2xxxx-17-00-00-de-008
• The measuring range begins, where the beam hits the tank bottom. Particularly with dish bottoms
or conical outlets the level cannot be detected below this point.
• For Wave Guide antennas, the end of the pipe is the begin of the measuring range.
• In case of media with a low dielectric constant (groups A and B), the tank bottom can be visible
through the medium at low levels (low height
C
). Reduced accuracy has to be expected in this
range. If this is not acceptable, we recommend positioning the zero point at a distance
C
(see Fig.)
above the tank bottom in these applications.
• In principle it is possible to measure up to the tip of the antenna with FMR230/231/240.
However, due to considerations regarding corrosion and build-up, the end of the measuring range
should not be chosen any closer than
A
(see Fig.) to the tip of the antenna.
For FMR244/245, the end of measuring range should not be chosen closer than
A
(see Fig.) to
the tip of the antenna, especially if there is development of condensate.
• The smallest possible measuring range
B
depends on the antenna version (see Fig.).
• The tank diameter should be greater than
D
(see Fig.), the tank height at least
H
(see Fig.).
Note!
• In case of
boiling surfaces, bubbling
or tendency for
foaming,
use FMR230 or FMR231.
Depending on its consistence, foam can either absorb microwaves or reflect them off the foam
surface. Measurement is possible under certain conditions.
• In case of heavy
steam development
or
condensate
the max. measuring range of FMR240 may
decrease depending on density, temperature and composition of the steam
→
use FMR230 or
FMR231.
• For the measurement of absorbing gases such as
ammonia NH
3
or some
fluorocarbons
1)
,
please use FMR230 in a stilling well.
1)
Affected compounds are e.g. R134a, R227, Dymel 152a.
100%
0%
B
A
C
H
Ø D
A [mm/inch]
B [m/inch]
C [mm/inch]
D [m/inch]
H [m/inch]
FMR240
50 / 2
> 0,2 / > 8
50...150 / 2...6
> 0,2 / > 8
> 0,3 / > 12
