12
EB 8389-1S EN
Description
Table 1:
Diagnostic functions and test analysis
Diagnostic functions
Control
valve
On/off
valve
Assessment
See section
Monitoring
Data logger
•
•
Depending on trigger status
selected
u
Valve signature
•
U
−
Change in friction
−
Supply pressure
−
Defective actuator springs
−
Pneumatic leakage
u
On/off valve
–
•
−
Breakaway time
−
Transit time
−
Valve end position
u
Valve position
histogram
•
U
−
Change in manipulated variable
range
−
Manipulated variable range
u
Set point deviation
histogram
•
•
−
Manipulated variable range
limitation
−
Seat leakage
−
Positioner-valve linkage
−
Average set point deviation
u
Cycle counter
histogram
•
•
−
Packing leakage
−
Dynamic stress factor
u
Leakage sensor
•
•
−
Seat leakage
u
Course of end
position
•
•
−
Course of end position
−
Zero shift
u
Dynamic tests
Valve dead band
•
•
−
Dead band
u
Partial stroke test
(PST)
•
•
−
Overshooting
−
Dead time
−
T86
−
Settling time
u
Full stroke test (FST)
•
•
−
Overshooting
−
Dead time
−
T86
−
Settling time
u
• Full scope of functions
U
Function is performed, but not analyzed
– Function is not performed
Description