Emerson Process Management 5300 manual Handling of Disturbances from Nozzle, Trim Near Zone

Rosemount 5300 Series

Reference Manual

00809-0100-4530, Rev BA July 2009

HANDLING OF DISTURBANCES FROM NOZZLE

Trim Near Zone

Using the Trim Near Zone Function

Figure C-2. Echo Curve before and after Trim Near Zone.

For transmitters using the Guided Wave Radar technology the performance In the Near Zone (referred to as the region between 0-3.3 ft. (0-1 m) below the Upper Reference Point) is normally somewhat limited. However, the Rosemount 5300 transmitter is equipped with a software functionality that minimizes the Upper Transition Zone. The factory setting is normally sufficient and doesn’t need to be repeated after installation.

However, since the setting is optimized depending on actual installation, further trimming may be necessary in the case of unfavorable conditions. An example is if there are disturbing obstacles in the Near Zone. Trimming means that the measurement performance in the Near Zone is maintained even under these conditions and prevents false echo indication.

NOTE!

Make sure that the product level is below the Near Zone region

(0-3.3 ft. (0-1 m) below the Upper Reference Point) before performing the Trim Near Zone.

Trim Near Zone

NOTE!

The Trim Near Zone function should only be used for reducing impact from stationary disturbances. It is not suitable for occasional disturbances.

Trim Near Zone can be done in RRM. The function can be reached from Device Specific Configuration in the Guided Setup (if the command is recommended) or from the Advanced Configuration window, Trim Near Zone tab.

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