Emerson Process Management 5300 manual Changing the Upper Null Zone, Figure C-4. Upper Null Zone

Reference Manual

00809-0100-4530, Rev BA July 2009

Rosemount 5300 Series

Changing the Upper Null Zone

Measurements are not performed within the Upper Null Zone (UNZ). By setting the UNZ parameter to zero, measurements can be performed in the region close to the flange (Near Zone).

If there are measurement problems in the upper part of the tank, you may use the Trim Near Zone function as described above.

If the desired measurement range is below the Near Zone, or if disturbing objects are located below the Near Zone, the Upper Null Zone parameter can be used to avoid measurements above a certain level.

To set the Upper Null Zone with a 375 Field Communicator:

1.Select the HART command [2, 1, 2, 3].

2.Select the Upper Null Zone option.

3.Enter the desired value.

To set the Upper Null Zone with RRM:

1.Start RRM.

2.Click the Tank icon in the Device Config/Setup toolbar.

3.Select the Probe tab in the Tank window.

4.Type the desired value in the Upper Null Zone field.

5.Click the OK button. Now the Upper Null Zone is stored in the transmitter memory.

Figure C-4. Upper Null Zone.

Upper Reference Point

Upper Null

Zone

Reference Gauge Height

Product Level

Figure C-5. Identifying the Upper

Null Zone in the Echo Curve plot

	Upper Null Zone
mV	Disturbance
Amplitude,
	3.0	5.0
	Distance, m

C-7