Measurement Response; Damping - Siemens SITRANS L Operating Instructions Manual

Technical reference
C.5 Measurement Response
C.5

Measurement Response

Note
Units are defined in Units (2.3.1.) and are in meters by default.
Response Rate (2.3.8.1.) limits the maximum rate at which the display and output respond
to changes in the measurement. There are three preset options: slow, medium, and fast.
Once the real process fill/empty rate (m/s by default) is established, a response rate can be
selected that is slightly higher than the application rate. Response Rate automatically adjusts
the filters that affect the output response rate.
Response Rate
(2.3.8.1.)
*
C.6

Damping

Filter time constant (2.6.8.1.) (Page 114) smooths out the response to a sudden change in
level. This is an exponential filter and the engineering unit is always in seconds.
In 5 time constants the output rises exponentially: from 63.2% of the change in the first time
constant, to almost 100% of the change by the end of the 5th time constant.
Damping example
time constant = 2 seconds input (level)
change = 2 m
184
Fill Rate per Minute (2.3.8.2.)/Empty Rate per
Minute (2.3.8.3.)
Slow
Medium
Fast
0.1 m/min (0.32 ft/min)
1.0 m/min (3.28 ft.min)
10.0 m/min (32.8 ft/min)
Operating Instructions, 07/2021, A5E32337680-AF
Filter time constant
(2.6.8.1.)
10 s
10 s
0 s
SITRANS LR200 with PROFIBUS PA