Siemens 7ML5431 Operating Instructions Manual page 128

Parameter reference
Propogation Factor (2.8.3.)
Note
• When operating in a stillpipe, values for CLEF Range (2.8.4.4.), and for the propagation
factor, should be set according to the pipe size. See the table below.
• For reliable results the antenna size must be close to the pipe size.
Compensates for the change in microwave velocity due to propagation within a metal
stillpipe instead of in free space.
Values
Nominal Pipe Size
Propagation Factor
CLEF Range (2.8.4.4.) settings Low calibra-
Since pipe dimensions may vary slightly, the propagation factor may also vary.
a)
CLEF range covers the whole measurement range except first 700 or 1000 mm from unit refer-
b)
ence point (see A in graphic below)
①
②
A
Note
Flanged encapsulated antenna
For Flanged encapsulated antenna (7ML5432) match the process connection size to the
pipe diameter whenever possible (for example, mount a DN80/3" flange on DN80/3" pipe).
128
a)
sensor reference point
air gap
700 or 1000 mm
Range 0.3 to 1.0 depending on pipe size
Default 1.0000
40 mm (1.5") 50 mm (2")
0.9844 0.988
Low calibra-
tion point - tion point -
700 mm 700 mm
(2.29 ft) (2.29 ft)
b) b)
③
low calibration point
④
CLEF range 2.8.4.4.
Operating Instructions, 10/2019, A5E32220602-AG
80 mm (3") 100 mm (4")
0.9935 0.9965
Low calibration Low calibration
point -1000 mm point -1000 mm
(3.28 ft) (3.28 ft)
b)
SITRANS LR250 with mA/HART
b)