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57-642 ECLIPSE Model 705 Guided Wave Radar Transmitter for Hygienic Industries
NOTE: Consider sliding a
9
⁄
16
" hose over the electro polished rod to pre-
vent damage to the probe during the bending operation.
Errors in bending can be corrected by cutting the incorrect
portion of the probe and welding a new piece of material to
the probe with matching specifications using a full penetra-
tion weld to maintain sterility.
After bending or modification, inspect the probe finish and
polish as necessary to obtain the required surface finish.
4.2.3 Accommodating Non-Linearity
Any non-vertical portion of the probe represents non-linear-
ity in the measurement. When designing a new installation
for which a probe is going to be bent, the ideal process con-
nection size is at least 2" for GWR probes ½" in diameter.
This will allow a rigid probe to be installed through the
nozzle with the highest degree of ease. For smaller diameter
probes (e.g., approx. ¼" diameter), a ¾" or 1" connection is
sufficient. Typically, these smaller probes are found in small
vessels where the installation is not as difficult, regardless of
connection size.
If the probe can potentially deflect and be caught by an agi-
tator or other moving component within a tank, a “capture
ring” should be incorporated into the installation design to
prevent the probe from deflecting more than 3 inches (75
mm) per 6 feet (1.8 m) of probe length. (See figure at left
for example.) Contact the manufacturer for assistance in the
design and application of the capture ring.
There are no performance concerns when incorporating a
capture ring. However, make sure the probe does not touch
the ring when there is no liquid present. During typical
operation, the liquid level should be above the ring so that
all signals reflect off the liquid level rather than reflect off
the capture ring.
A capture ring should be constructed from ¼" round bar
stock formed into a circle at one end. A 2" diameter is ideal
for the circle and should share the same centerline as the
probe. A length of bar stock should be extended from this
circle to the nearest portion of the tank that will allow the
ring to be welded for connection.
An ideal location for a capture ring is as low as possible
along the probe to minimize potential dead-band issues that
may result from product hang-up on the ring. The capture
ring should be installed below the lowest measuring point if
possible, but high enough such that the probe will not be
able to jump out of the ring during operation.
One method for stabilizing probe
within a vessel
