Mounting Instructions - Siemens SITRANS LG240 Operating Instructions Manual

Suitability for the ambient
conditions
Installation position
Type of vessel
14
The instrument is suitable for standard and extended ambient condi-
tions acc. to DIN/EN/IEC/ANSI/ISA/UL/CSA 61010-1.
4.2

Mounting instructions

Mount SITRANS LG240 in such a way that the distance to vessel
installations or to the vessel wall is at least 300 mm (12 in). In non-
metallic vessels, the distance to the vessel wall should be at least
500 mm (19.7 in).
During operation, the probe must not touch any installations or the
vessel wall. If necessary, fasten the probe end.
In vessels with conical bottom it can be advantageous to mount the
sensor in the center of the vessel, as measurement is then possible
nearly down to the lowest point of the bottom. Keep in mind that
measurement all the way down to the tip of the probe may not be pos-
sible. The exact value of the min. distance (lower dead band) is stated
in chapter "Technical data" of the operating instructions.
Fig. 4: Vessel with conical bottom
Plastic vessel/Glass vessel
The guided microwave principle requires a metallic surface on the
process fitting. Therefore, in plastic vessels, etc., use an instru-
ment version with flange (from DN 50) or place a metal sheet
(ø > 200 mm/8 in) beneath the process fitting when screwing it in.
Make sure that the plate has direct contact with the process fitting.
When mounting rod or cable probes in vessels without metal walls,
e.g. in plastic vessels, the measured value can be influenced by
strong electromagnetic fields (emitted interference according to
EN 61326: class A). In this case, use a probe with coaxial version.
SITRANS LG240 - Operating Instructions PBD-51041038