Emerson Rosemount 3308, Справочное руководство

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Reference Manual
00809-XXXX-4811, Rev AA
February 2012
A-9
Rosemount 3308
PRELIMINARY
Total Probe Length This is defined from the upper reference point to the end of the probe (weight included, if applicable).
Select the probe length according to the required measuring range (the probe must be hung and fully
extended through the entire distance where level readings are desired).
Cut-to-fit probes Most of the probes can be cut in field. However, there are some restrictions for the standard coaxial probes:
these can be cut up to 2 ft. (0.6 m). Probes shorter than 4.1 ft. (1.25 m) can be cut to the minimum length of
1.3 ft. (0.4 m). The PTFE covered probes cannot be cut in the field.
Minimum and Maximum
Probe Length TO BE ADDED
Probe Angle 0 to 90 degrees from vertical axis
Tensile Strength Flexible Single Lead probe: 2698 lb (12 kN). Flexible Twin Lead probe: 2023 lb (9 kN)
Collapse Load Flexible Single Lead probe: 3597 lb (16 kN)
Sideway Capacity Coaxial probe: 73.7 ft. lbf, 3.7 lb at 19.7 ft. (100 Nm, 1.67 kg at 6 m)
Rigid Twin Lead: 2.2 ft. lbf, 0.22 lb at 9.8 ft. (3 Nm, 0.1 kg at 3 m)
Rigid Single Lead: 4.4 ft. lbf, 0.44 lb at 9.8 ft. (6 Nm, 0.2 kg at 3 m)
Maximum Recommended
Nozzle Height 4 in. (10 cm) + nozzle diameter
For coaxial probes, there are no restrictions
Minimum Clearance
(See Table A-7 on
page A-11)
Other Mechanical
Considerations To get best possible performance, the following must be
considered before installing the transmitter:
• Inlets should be kept at a distance in order to avoid product
filling on the probe
• Avoid physical contact between probes and agitators, as well
as applications with strong fluid movement unless the probe is
anchored
• Probe tie-down is recommended if the probe can move to
within 1 ft. (30 cm) of any object during operations
• In order to stabilize the probe for side forces, it is possible to
fix or guide the probe to the tank bottom
• For optimal single lead probe performance in non-metallic
vessels, the probe must either be mounted with a 2-in. / DN 50 or larger metallic flange, or a metal sheet
with an 8-in. diameter (200 mm) or larger must be used (see the Reference Manual for placement)
Total
Probe
Length
NPT BSP/G
Flange
Tri-Clamp
Upper
Reference
Point
Nozzle Diameter
Nozzle
Height
Clearance to tank wall
Flexible single lead probe with chuck.