KROHNE BM 70 A Installation And Operating Instructions Manual page 22

It is possible to measure through a full-bore open ball valve if the valve and the pipe adapters above
and below the valve are relatively smooth-walled.
• It is not possible to measure levels below the end of the stilling well.
• To ensure equalization of pressure, drill one or two small holes in the stilling well above the
maximum filling level.
• If necessary, several holes can be drilled along the
whole length of the pipe. All holes must be
deburred. The holes should be as small as
possible and spaced wide apart (Recommen-
dation: see drawing on the right).
• It is advisable to fit a reference point at the end of
the stilling well in the form of a rod or screw of
approx. 6 mm (0.24") diameter. See drawing
below.
6.1.5 Wave-Guide
The "Wave-Guide" is a pipe with an outside diameter of 30 mm (1.18") and an inside diameter of 25
mm (0.98"), that is bolted direct to the BM 70 A flange system (in the same way as an antenna
extension). It functions like a stilling well and can be used for clean products. The Wave-Guide is not
practical in conjunction with the BM 70 P as it will not provide high measuring accuracy.
maximum length:
Ex: max. 3 m (9.84 ft) (except tantalum: max. 1 m (3.28 ft)).
Non-Ex: up to 3 m (9.84 ft) without additional support
Pipes longer than 3 m (9.84 ft) need to be fixed at two points.
6.1.6 Curved antenna extensions
Rectangular and S-shaped extensions are available for particularly difficult operating conditions. Such
extensions can be used in cases where the antenna is exposed to especially high temperatures and
where there are problems of space, (e.g. to avoid internals; positioning the antenna away from the
centre of sy mmetry; lateral mounting of the signal converter).
Installation and operating instructions BM 70 A/P
6 mm Ø
Ø 6 mm
Ø 0.24"
Standard sizes (others on request):
271 (10.67")
R 110 (4.33")
Dimensions in mm (inches)
min.
50 mm
300 (11.81")
Page: 22
Ø max.
10 mm
/ 0.4"
/ 1.97"
11/00