Emerson Rosemount 3308A Reference Manual page 189

Reference Manual
00809-0100-4308, Rev CA
Near zone threshold
Threshold control
The Near Zone Threshold can be automatically calculated by device or manually set by user.
Threshold
Threshold to filter out noise in a zone near the device. Noise below the threshold is suppressed. This
threshold replaces the Surface threshold in the zone where it is applicable.
Distance
Distance from Upper Reference Point (normally the lower side of device flange) to point where the near
zone threshold ends.
Near zone trimming
Trim near zone
Select to activate trimming.
The Trim Near Zone method is used to fine tune performance in the area close to the tank top. This
function is normally not used. Trim Near Zone is typically used if there are problems related to the nozzle.
For more information see section
Near zone has been trimmed
Indicates if the Trim Near Zone method has been used for this device.
Advanced
Peak detection method
Select which peak detection to use for level measurements. For further information on when to use the
peak detection method, see section
Table D-6. Peak Detection Methods
Option
Peak Center
Threshold Intersection
Figure D-11. Peak Detection Method
A. Threshold Intersection
B. Peak Center
C. Surface Threshold
Configuration Parameters
PRELIMINARY
"Using the trim near zone function" on page
"Resolving thin oil layers" on page
Description
Surface detected at the first amplitude peak closest to device detected above the
Surface Threshold.
Surface detected at first intersection with Surface Threshold.
B
A
Configuration Parameters
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C
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