Orion Instruments Eclipse 705 - Manual (Page 33)

33 57-600 Eclipse ® Guided Wave Radar Transmitter
2.6.6 Offset Description
The parameter referred to as Lvl Ofst in the ECLIPSE menu
is the desired level reading when liquid surface is at the end
of the probe. The ECLIPSE transmitter is shipped from the
factory with Lvl Ofst set to 0. With this configuration, all
measurements are referenced from the bottom of the probe.
See Example 1.
Example 1 (Lvl Ofst = 0 as shipped from factory):
Application calls for a 72-inch NPT Coaxial probe in
water with the bottom of the probe 10 inches above the
bottom of the tank. The user wants the 4 mA point at
24 inches and the 20 mA point at 60 inches as referenced
from the bottom of the probe.
In those applications in which it is desired to reference all
measurements from the bottom of the vessel, the value of
Lvl Ofst should be changed to the distance between the
bottom of the probe and the bottom of the vessel as shown
in Example 2.
Example 2:
Application calls for a 72-inch NPT coaxial probe in
water with the bottom of the probe 10 inches above the
bottom of the tank. The user wants the 4 mA point at
24 inches and the 20 mA point at 60 inches as referenced
from the bottom of the tank.
When the ECLIPSE transmitter is mounted in a
chamber/bridle, it is usually desirable to configure the unit
with the 4 mA (0%) point at the lower process connection
and the 20 mA (100%) point at the upper process connection.
The span is the center-to-center dimension. In this case, a
negative Lvl Ofst needs to be entered. In doing so, all
measurements are then referenced at a point up on the
probe as shown in Example 3.
Example 3:
Application calls for a 48-inch cage-coaxial flanged probe
measuring water in a chamber with the bottom of the
probe 6 inches below the lower process connection. The
user wants the 4 mA point to be 0 inches at the bottom
process connection and the 20 mA point to be 30 inches
at the top process connection.
10"
60"
20 mA
4 mA
24"
PrbModel
7xA-x
PrbMount
NPT
LvlUnits
in
Probe Ln
72 in
Lvl Ofst
0.0 in
Dielctrc
10-100
Set 4mA
24.0 in
Set 20mA
60.0 in
Example 1
10"
60"
20 mA
4 mA
24"
PrbModel
7xA-x
PrbMount
NPT
LvlUnits
in
Probe Ln
72 in
Lvl Ofst
10 in
Dielctrc
10-100
Set 4mA
24.0 in
Set 20mA
60.0 in
Example 2
6"
30"
4 mA
20 mA
PrbModel
7xR-x
PrbMount
Flange
LvlUnits
in
Probe Ln
48 in
Lvl Ofst
-6.0 in
Dielctrc
10-100
Set 4mA
0 in
Set 20mA
30.0 in
Example 3