VEGA VEGAPULS 66 (≥ 2.0.0 - ≤ 3.8) Profibus PA - Manual (Page 16)

Fig. 7: Inflowing liquid
The socket piece should be dimensioned in such a way that the
antenna end protrudes at least 10 mm (0.4 in) out of the socket.
ca. 10 mm
Fig. 8: Recommended socket mounting
If the socket height cannot be maintained, an antenna extension will be
necessary. This prevents from false reflections of the socket piece.
Socket
16 VEGAPULS 66 • Profibus PA
4 Mounting
28448
-EN
-090305