Measurement Response; Damping - Siemens SITRANS LR560 Operating Instructions Manual

A.5

Measurement response

Note
Units are defined in Quick Start Wizard (1.1.) and are in meters by default.
RESPONSE RATE (2.3.6.1.) (Page 125) 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
(2.3.6.1.) (Page 125)
Factory
setting:
A.6

Damping

FILTER TIME CONSTANT (2.5.7.1.) (Page 140) 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
LR560 (FOUNDATION FIELDBUS)
Operating Instructions, 06/2018, A5E34648692-AE
FILL RATE/MIN (2.3.6.2.)
(Page 126)/EMPTY RATE/MIN (2.3.6.3.)
(Page 126)
Slow 0.1 m/min (0.32 ft/min)
Medium 1.0 m/min (3.28 ft.min)
Fast 10.0 m/min (32.8 ft/min)
Technical reference
A.5 Measurement response
FILTER TIME
CONSTANT (2.5.7.1.)
(Page 140)
600 s
60 s
0 s
195