Volume Parameters - Emerson Rosemount Apex Reference Manual

™
APEX and APEX Sentry
Special Cases
Figure 3-2. Reflecting the Signal
in a Dish-Bottom Tank
3-4
™
Radar Gauge

Volume Parameters

• Refer to "Set Volume Units" on page 3-19 if using a HART
communicator to configure the volume parameters.
• Refer to "Setup - Volume" on page 3-32 if using RCT to configure the
volume parameters.
Dish-bottom Tanks, Empty Tank Detection
Radar gauges require a horizontal surface, such as the product surface or the
bottom of the tank, to reflect the signal back up to the antenna. When a
dish-bottom tank is emptied and the surface is no longer horizontal, there may
not be a sufficient amount of signal reflected to get a level reading (see Figure
3-2). If this happens, the radar gauge indicates a lost signal condition unless
the empty tank detection zone is configured.
Empty Tank Line
The gauge has an empty tank setting designed to handle this situation. To
prevent the gauge from indicating "Lost Signal" in empty tank situations, the
empty tank setting forces it to report "Empty Tank" if the signal is lost when
the level goes below the setting.
Reference Manual
00809-0100-4731, Rev FA
Reference
Gauge Height
URV
(20 mA)
LRV
Reference
(4 mA)
Line
April 2003