Endress+Hauser Micropilot FMR51 - Measuring Conditions

Installation Micropilot FMR51, FMR52 PROFIBUS PA
18 Endress+Hauser
FMR52
Antenna size 50 mm (2 in) 80 mm (3 in)
Beam angle α 18° 10°
Measuring distance (D) Beamwidth diameter W
3 m (9.8 ft) 0.95 m (3.1 ft) 0.53 m (1.7 ft)
6 m (20 ft) 1.9 m (6.2 ft) 1.05 m (3.4 ft)
9 m (30 ft) 2.85 m (9.4 ft) 1.58 m (5.2 ft)
12 m (39 ft) 3.80 m (12 ft) 2.1 m (6.9 ft)
15 m (49 ft) 4.75 m (16 ft) 2.63 m (8.6 ft)
20 m (66 ft) 6.34 m (21 ft) 3.50 m (11 ft)
25 m (82 ft) 7.92 m (26 ft) 4.37 m (14 ft)
30 m (98 ft) 9.50 m (31 ft) 5.25 m (17 ft)
35 m (115 ft) 11.09 m (36 ft) 6.12 m (20 ft)
40 m (131 ft) 12.67 m (42 ft) 7.00 m (23 ft)
45 m (148 ft) - 7.87 m (26 ft)
60 m (197 ft) - 10.50 m (34 ft)
6.2 Measuring conditions
• In case of boiling surfaces, bubbling or tendency for foaming use FMR53 or FMR54.
Depending on its consistence, foam can either absorb microwaves or reflect them off the
foam surface. Measurement is possible under certain conditions. For FMR50, FMR51 and
FMR52, the additional option "Advanced dynamics" is recommended in these cases (feature
540: "Application Package", option EM).
• In case of heavy steam development or condensate, the maximum measuring range of
FMR50, FMR51 and FMR52 may decrease depending on density, temperature and
composition of the steam → use FMR53 or FMR54.
• For the measurement of absorbing gases such as ammonia NH
3
or some fluorocarbons
1)
,
please use Levelflex or Micropilot FMR54 in a stilling well.
• 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 stilling well applications, the zero should be positioned at the end of the tube, as the
electromagnetic waves do not propagate completely outside the tube. It must be taken into
account that the accuracy may be reduced in the area C. In order to guarantee the required
accuracy in these cases, it is recommended to position the zero-point at a distance C above
the end of the tube (see figure).
1) Affected compounds are e.g. R134a, R227, Dymel 152a.