Rosemount 5900S Radar Level Gauge for Custody Transfer

Overview

The Rosemount 5900S is Emerson’s premium non-contact radar level gauge for bulk liquid storage tanks at terminals and refineries. Its headline figure is an instrument accuracy of 0.5 mm, certified for custody transfer according to OIML R85 and other legal metrology authorities, which reduces level uncertainty to a minimum for inventory management and loss control. The Rosemount 5900S is part of the Rosemount Tank Gauging System, where it is normally combined with multi-spot temperature sensors to calculate net standard volumes to API and other standards.

Seven Star LLC supplies the Rosemount 5900S to tank terminal operators, refineries, petrochemical plants and EPC contractors in Oman and the GCC, from our office in Muscat. Crude export terminals, refined product depots, LPG storage and aviation fuel farms in the region depend on precise level data for fiscal accounting, and an overfill-safe gauge also supports the safety case for every large atmospheric tank.

Measurement Principle

The data sheet describes the FMCW method used by the Rosemount 5900S. The transmitted radar signal has a linear frequency variation around 10 GHz. When the reflection from the liquid surface returns, its frequency differs slightly from the signal being transmitted at that moment, and this difference is directly proportional to the distance between the antenna and the surface, and therefore to the liquid level. Emerson states that this technology gives a very accurate and stable measured value, with a new measurement every 0.3 s and a repeatability of 0.2 mm.

As general engineering background, a non-contact gauge has no float, tape or displacer in the tank, so there is no mechanical wear, no sticking in waxy crude and no need to empty the tank to service the measurement. Emerson adds that most Rosemount 5900S antenna types can be installed with the tank in operation, and that the drip-off antenna design with inclined, polished PTFE surfaces reduces condensation from product and water, keeping the radar signal strong. Electronics can be sealed for metrology where required.

Engineering Design of the Rosemount 5900S

All Rosemount 5900S antennas share the same transmitter head, which minimises spare parts. The dual-compartment housing of polyurethane-coated die-cast aluminium separates electronics and cabling, can be replaced without opening the tank, and is protected against lightning, moisture and rain, with surface protection against sulphur and salt-spray atmospheres. Antenna choices are the parabolic antenna for fixed-roof tanks without a still-pipe, the horn antenna for smaller openings, the still-pipe array antenna for floating-roof tanks with still-pipes, and the LPG/LNG antenna for pressurised and refrigerated gas storage.

The gauge is powered and communicates over the two-wire intrinsically safe Tankbus (FOUNDATION Fieldbus FISCO), typically from a Rosemount 2410 Tank Hub, with a bus current of 50 mA, or 100 mA for the 2-in-1 version. The 2-in-1 option places two galvanically separated gauge units in one housing with a shared antenna, providing either a primary and backup level unit or a level gauge plus an independent radar high-high alarm, using a single tank opening. Configuration is done with Rosemount TankMaster WinSetup or a Field Communicator, and wired and wireless data transmission are both possible.

Key Features

The Rosemount 5900S data sheet emphasises these features.

• Instrument accuracy of 0.5 mm with certified custody transfer approval under OIML R85:2008.
• Third-party certified IEC 61508 SIL 2 capability, and SIL 3 with the 2-in-1 option, for overfill prevention.
• The 2-in-1 design puts two independent gauges in one housing for level redundancy through one tank opening.
• Repeatability of 0.2 mm and a new measurement every 0.3 s support tight inventory control.
• Parabolic, horn, still-pipe array and LPG/LNG antennas cover every common bulk storage tank type.
• Drip-off antenna design with polished PTFE surfaces minimises the effect of condensation.
• Two-wire intrinsically safe Tankbus power and communication simplifies safe installation.
• One common transmitter head for all antennas can be replaced without opening the tank.

Industrial Applications

Emerson states that the Rosemount 5900S measures in all bulk storage tank types and products, ranging from liquefied gases and light products to crude oil and bitumen. In Oman this includes crude oil tanks at export terminals, refined product and jet fuel tanks at refinery tank farms in Sohar and Duqm, LPG spheres and bullets, and storage at petrochemical complexes and bulk liquid terminals near major ports. The SIL-certified alarm functions support overfill prevention systems designed in line with API 2350, with the alarm signal routed through the tank hub to an emergency shutdown or automatic overfill prevention system.

Seven Star LLC supplies the Rosemount 5900S across the Sultanate of Oman and the GCC as part of complete tank gauging packages, alongside instruments such as the Rosemount 3144P temperature transmitter and Rosemount 214C RTD temperature sensor for single point temperature, and the Rosemount 3051S coplanar pressure transmitter for vapour and hydrostatic pressure inputs.

Technical Specifications

The main Rosemount 5900S values below are taken from Emerson product data sheet 00813-0100-5900.

How to Order

To request a Rosemount 5900S quotation, send Seven Star LLC your tank list with tank type, roof type, nozzle or still-pipe size, product, custody transfer and SIL requirements. The Emerson product data sheet can be downloaded from this page. Seven Star LLC supplies Rosemount tank gauging equipment from Muscat to terminals and refineries throughout Oman and the GCC, with sourcing and model selection support for system design and commissioning.