Troubleshooting guide

95
Reference Manual
00809-0100-4308, Rev BA
Section 6: Service and Troubleshooting
December 2014
Service and Troubleshooting
Note
Before changing the Upper Null Zone, check entered limit and deadband values for the High
Level Alerts. High Level Alerts should not be placed in the Upper Null Zone.
To set the Upper Null Zone do the following:
1. Identify desired Upper Null Zone using the Echo Curve plot:
a. Start the Echo Curve reading, refer to “Reading the Echo Curve” on page 83.
b. View the Echo Curve plot to find out if there are disturbing echoes close to the tank
top.
2. Set the desired Upper Null Zone value:
a. From the Home Screen, go to Configure > Manual Setup > Level Setup > Probe >
Advanced Probe Options.
b. Under Upper Null Zone, type the desired value into the box and then click Send.
Figure 6-15. Upper Null Zone
Figure 6-16. Upper Null Zone Is Extended to Block Out Disturbances at the Top of the Tank
Upper Null Zone
Upper Reference Point
Measurement Range
3.0
5.0
Upper Null
Zone
Disturbance
Product Surface Peak
AMPLITUDE
DISTANCE