Endress+Hauser Micropilot FMR53, Техническая информация, Страница: 43 / 92

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Micropilot FMR53, FMR54
Hauser V. 1, Rev. 7, 26-10-2012 43
Recommendations for the stilling well
• Metal (no enamel coating; plastic on request).
• Constant diameter.
• Diameter of stilling well not larger than antenna diameter.
• Weld seam as smooth as possible and on the same axis as the slots.
• Slots offset 180° (not 90°).
• Slot width or diameter of holes max. 1/10 of pipe diameter, de-burred. Length and number do not have
any influence on the measurement.
• Select horn antenna as big as possible. For intermedaite sizes (e.g. 180 mm (7 in)) select next larger
antenna and adapt it mechanically (for horn antennas)
• At any transition (i.e. when using a ball valve or mending pipe segments), no gap may be created
exceeding 1 mm (0.04 in).
• The stilling well must be smooth on the inside (average roughness R
z
≤ 6.3
m
m (248
m
in)). Use extruded
or parallel welded stainless steel pipe. An extension of the pipe is possible with welded flanges or pipe
sleeves. Flange and pipe have to be properly aligned at the inside.
• Do not weld through the pipe wall. The inside of the stilling well must remain smooth. In case of
unintentional welding through the pipe, the weld seam and any unevenness on the inside need to be
carefully removed and smoothened. Otherwise, strong interference echoes will be generated and material
build-up will be promoted.
• Particularly on smaller nominal widths it needs to be observed that flanges are welded to the pipe such
that they allow for a correct orientation (marker aligned toward slots).
The performance of Micropilot FMR54 with planar antenna is not dependent on the alignment or
geometry of standard stilling wells. No special alignment is required. However, make sure that the
planar antenna is installed vertically relative to the stilling well axis.