Micropilot S FMR533 4 to 20 mA HART
Mounting
Hauser
13
Measuring conditions
• 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
overspill protection
, it is possible to define a safety distance
(SD)
additionally to the
blocking distance
(BD)
.
• Depending on its consistence, foam can either absorb microwaves or reflect them off the foam
surface. Measurement is possible under certain conditions.
• The smallest possible measuring range
B
depends on the antenna version (see Fig.).
• Tank diameter and height should be at least dimensioned such that a reflection of the radar signal
on both sides of the tank can be ruled out ("Beam angle",
• 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 applications with
parabolic antenna
, especially for media with low dielectric constants
(media group A and B,
14) , the end of the measuring range should not be closer than
1 m (40") to the flange (cf.
BD
in Fig.).
• The safety distance
(SD)
is set to 0.5 m (20") by default, generating an alarm in case the product
level rises inside the safety distance.
L00-FMR533xx-17-00-00-en-011
Behaviour if measuring range is exceeded
The behaviour in case of the measuring range being exceeded can be freely set:
The default setting is a current of 22 mA and the generation of a digital warning (E681).
reference: flange / BD (cf. picture)
reference: antenna tip (cf. picture)
Blocking distance
Safety distance
recommended additional settings
BD [m (ft)]
SD [m (ft)]
A [mm (in)]
B [m (ft)]
C [mm (in)]
FMR533
1 (3.28)
0.5 (1.6)
1000 (40)
0.5 (1.64)
150 to 300 (6 to 12)
BD
SD
A
B
C
100%
0%
max. level
