User's Manual

Appendix A: Technical reference
A.2 Echo processing
SITRANS LR250 (FOUNDATION FIELDBUS)
Operating Instructions, 01/2014, A5E32221411-AB
235
A.2.4
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.
Note
Changing R
esponse Rate resets
Fill Rate per Minute (2.3.8.2.)
,
Empty Rate per Minute
(2.3.8.3.)
, and
Shots (2.5.6.)
.
Response Rate
(2.3.8.1)
Fill Rate (2.3.8.2)/Empty Rate (2.3.8.3)
*
Slow
0.1 m/min (0.32 ft/min)
25
Medium
1.0 m/min (3.28 ft.min)
10
Fast
10.0 m/min (32.8 ft/min)
5
A.2.5
Echo Threshold
Confidence (2.5.9.1.)
describes the quality of an echo. Higher values represent higher quality.
Echo Threshold (2.5.7.3.)
defines the minimum confidence value required for an echo to be
accepted as valid and evaluated.