Endress+Hauser Levelflex FMP51 Brief Operating Instructions page 16

Mounting
 probe
8 mm (1/3")
12 mm (1/2")
16 mm (0.63in)
NOTICE
Poor grounding of the end of probe may cause measuring errors.
‣
Apply a narrow sleeve which has good electrical contact to the probe.
NOTICE
Welding may damage the main electronics module.
‣
Before welding: Ground the probe and dismount electronics.
16
 a [mm (inch)]
< 14 (0.55)
< 20 (0.78)
< 26 (1.02)
Levelflex FMP51, FMP52, FMP54 PROFIBUS PA
 b [mm (inch)]
8.5 (0.34)
12.5 (0.52)
16.5 (0.65)
Endress+Hauser