VEGA VEGAPULS 81 - Manual (Page 43)

VEGAPULS 64 and 81 43
It is hence possible to optimize the thickness
of the penetrated substance so that the two
reflection waves eliminate or compensate each
other.
The following table shows the optimum sub-
stance thickness for the most important plas-
tics and glasses which are suitable for pen-
etration with radar sensors.
Note:
The optimum thickness or an integral multiple
of the optimum thickness can be also provided
by addition of several substance plate of iden-
tical materials. The plants must fit flush, with-
out gaps.
Penetrated substance
ε
r
optimum thickness D in mm
PE Polyethylene 2,3 17 (34; 51 …)
PTFE Polytetrafluorethylene 2,1 18 (36; 54 …)
PVDF Polyvinylidenfluoride ~ 7 8 (16; 24; 32 …)
PP Polypropylene 2,3 17 (34; 51 …)
Glass Borosilicate (Maxas, Duran) 5,5 11 (22; 33; 34 …)
Glass Rasotherm 4,6 12 (24; 36; 48 …)
Glass Labortherm 8,1 9 (18; 27; 36 …)
Quartz glass ~ 4 13 (26; 39; 52 …)
POM Polyoxymethylene 3,7 13,5 (27; 40,5; 54 …)
Polyester 4,6 12 (24; 36; 48 …)
Plexiglass Polyacrylate 3,1 14,5 (29; 43,5; 58 …)
PC Polycarbonate ~ 2,8 16 (32; 48 …)
Mounting and installation: Measurement through the vessel wall