Emerson Rosemount 3105 Level Transmitter

Emerson Rosemount 3105 Level Transmitter

While Annubar flowmeters excel at measuring flow rates, comprehensive process monitoring often requires level measurement as well. The Emerson Rosemount 3105 ultrasonic level transmitter provides a reliable, non-contacting solution for liquid level applications in storage tanks, effluent pits, reservoirs, and filter beds-37.

The Emerson Rosemount 3105 is a 4–20 mA loop-powered transmitter designed for continuous liquid level measurement in tanks or open flow channels-50. Key specifications include:

The Emerson Rosemount 3105 calculates distance-to-surface, contents (volume), or open channel flow, outputting results via both analog and HART digital signals-38. An integral temperature sensor automatically compensates distance calculations for temperature effects on the speed of sound in air. For enhanced accuracy, the Emerson Rosemount 3105 also supports an optional remote temperature sensor-38.

With a PVDF wetted side and glass-filled nylon housing, the Emerson Rosemount 3105 is suitable for hazardous and corrosive environments where contact-type instruments may fail. The non-contacting ultrasonic technology has no moving parts, ensuring long operating life with minimal maintenance requirements-52.

When specifying the Emerson Rosemount 3105, consider the 12-inch blanking distance requirement (the sensor cannot measure within this distance from its front face). The unit can be installed using the 2-inch BSPT thread directly onto a vessel or on a mounting bracket above the liquid surface-48.

Installation and Commissioning Best Practices

Proper installation is critical to achieving specified performance from any Annubar flowmeter. Key installation requirements include:

Straight-run requirements: Sufficient upstream and downstream straight pipe lengths must be maintained to ensure fully developed flow profile at the sensor location.

Orientation: The sensor must be correctly oriented with respect to flow direction. The T-shaped sensor design includes alignment features to ensure proper positioning.

Mounting configurations:

Direct mount: Transmitter mounted directly to the Annubar sensor (temperature limited to 500°F standard, 750°F with high-temperature manifold)

Remote mount: Transmitter mounted remotely with impulse piping (supports up to 1250°F process temperatures)

Flo-tap designs: Both the 485 and 585 Annubar series offer Flo-tap configurations, enabling installation and removal without system shutdown-.

For the Emerson Rosemount 3105 level transmitter, installation requires top-mount positioning above the liquid surface, with unobstructed vertical path to the liquid. The ultrasonic pulse must have a clear line of sight to the liquid surface — internal tank obstructions such as agitators, ladders, or baffles can interfere with signal return.

Maintenance and Diagnostics

The Rosemount Annubar series requires minimal maintenance due to the absence of moving parts in the primary element. The T-shaped sensor design positions the stagnation zone to keep particulates from clogging the pressure ports, reducing maintenance frequency in dirty or particulate-laden services-4.

The Rosemount 4088 transmitter includes basic diagnostics capabilities, while the 3051S Series platform offers advanced diagnostics for flow measurement verification-3. The Emerson Rosemount 3105’s non-contacting technology similarly requires no routine maintenance beyond periodic inspection of the transducer face for contamination.

Ordering Information

When ordering a Rosemount Annubar flowmeter, the following information is typically required:

Primary element model (485 or 585)

Line size and schedule

Fluid type (L = Liquid, G = Gas, S = Steam)

Process connection type and rating

Sensor material (316/316L SST, Alloy C-276, or Alloy 800H)

Mounting configuration (direct or remote mount)

Flo-tap requirement (if hot-tap capability is needed)

For the Emerson Rosemount 3105, ordering requires specification of measuring range, output type (4–20 mA with HART), hazardous area certification requirements, and process connection type.