Burkert 8138 Mise En Service page 11

Polarisation
LEVEL TRANSMITTER 8138 • 4 ... 20 mA/HART - two-wire
Suitable retaining elements are also available from us.
The retaining elements are attached with the versions for process
temperatures -196 ... +200 °C (-321 ... +392 °F).
Size Article no.
M16, / " 32880
7
8
M20, / " 32881
3
4
M24, / " 32882
5
8
To seal effectively, the following requirements must be fulfilled:
1. Make sure the number of flange screws corresponds to the num-
ber of flange holes
2. Use disc springs to compensate the preload loss of the PTFE
washer
Fig. 2: Use of disc springs
1 Single disc spring
2 Laminated disc spring
3. Tighten screws with the necessary torque (see chapter "Technical
data")
Note:
It is recommended, retightening the screws in regular intervals
depending on process pressure and temperature. Recommended
torque (see chapter "Technical data").
The emitted radar impulses of the radar sensor are electromagnetic
waves. The polarisation is the direction of the electrical wave compo-
nent. By turning the instrument in the connection flange or mounting
boss, the polarisation can be used to reduce the effects of false
echoes.
The position of the polarisation is marked on the process fitting of the
instrument.
Fig. 3: Position of the polarisation
1 Marking hole
Type
Detent edged ring
Gross VS KD
Detent edged ring
Gross VS KD
Retaining washer
Schnorr VS or S
2
1
1
4 Mounting
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