Emerson Rosemount 3308 Series Reference Manual page 31

Reference Manual
00809-0100-4308
The probe length determines if a single rigid or single flexible probe should be used:
• Less than 19.7 ft. (6.0 m): Rigid single probe is recommended. Use a centering disc for
probe > 3.3 ft. (1 m). When mounting space is limited, use a flexible single probe with a
weight and centering disc.
• More than 19.7 ft. (6.0 m): Use flexible single probe with a weight and centering disc.
PTFE covered probes are not recommended for chamber/pipe installations.
3.3.5 Installation in non-metallic tanks and open-air
applications
Avoid major sources of electrical disturbance in proximity of the installation (e.g. electrical
motors, stirrers, servo mechanisms).
Figure 3-6: Avoid Electromagnetic Disturbances
For clean liquids, use a coaxial probe to reduce effect of potential electrical disturbances.
Figure 3-7: Coaxial Probe in an Open-Air Application
For optimal single lead probe performance in non-metallic tanks, the probe must be
mounted with a metal flange, or screwed in to a metal sheet (d > 14 in./350 mm) if a
threaded version is used.
Reference Manual
Installation
February 2020
31