Rosemount 2240S Multi-input Temperature Transmitter

Overview

The Rosemount 2240S Multi-input Temperature Transmitter provides multiple spot temperature measurement in liquid storage tanks. Emerson uses it to calculate the average temperature of the liquid and to correct for stratification, which is essential when converting gauged level into net standard volume. The Rosemount 2240S connects up to sixteen 3- or 4-wire temperature elements and an integrated water level sensor, delivers a temperature conversion accuracy of 0.05 °C, and is approved for demanding custody transfer applications in line with API chapter 7.3.

Seven Star LLC supplies the Rosemount 2240S to crude and product terminals, refineries, LPG and LNG storage operators and EPC contractors in Oman and the GCC, from our office in Muscat. In large tanks a fraction of a degree of temperature error turns into a significant volume difference, so the transmitter is a key part of fiscal tank gauging alongside the radar level gauge.

Operating Principle

As the data sheet explains, the Rosemount 2240S reads each individual spot temperature element in a multiple spot temperature sensor installed in the tank. The value from each element is combined with the level value from the radar gauge, and the average liquid temperature is calculated from these values for net volume computation. Measured data, including temperature and free water level, is passed over the intrinsically safe two-wire Tankbus to a Rosemount 2410 Tank Hub, and can be viewed in Rosemount TankMaster software, on the tank hub display or on a Rosemount 2230 Graphical Field Display.

The water level sensor in the Rosemount 765 probe is factory calibrated, and any adjustment during installation can be made with the built-in on-line calibration feature of the transmitter. As general engineering background, measuring free water at the tank bottom matters because water must be subtracted from the gross volume, and a continuous electronic reading avoids manual dipping with water-finding paste on the tank roof.

Engineering Design of the Rosemount 2240S

The Rosemount 2240S is housed in a polyurethane-covered aluminium enclosure rated IP 66/67 and NEMA 4X, with ½-14 NPT or M20 x 1.5 cable connections, metal cable glands or Eurofast and Minifast connectors. It can be mounted directly on top of a Rosemount 565, 566 or 765 multiple spot sensor using an M33 x 1.5 connection, or separately on a wall or pipe with an installation kit. Supported sensors are the 565 multiple spot sensor, the 566 for cryogenic service such as LNG, the 765 with integrated water level sensor, and the 614 cryogenic spot sensor.

Inputs accept Pt-100 to IEC/EN 60751 and ASTM E1137, and Cu-90 elements, for use from -200 to 250 °C. Wiring can be 3-wire with common return, 3-wire individual or 4-wire individual, with up to 16 elements depending on the sensor model. The Tankbus is a FOUNDATION Fieldbus FISCO segment, with a quiescent current of 30 mA and a lift-off voltage of 9.0 VDC; the device is polarity insensitive and acts as a Link Master. TankMaster WinSetup is the recommended configuration tool, and the tank hub supports Tankbus auto-configuration. Metrology sealing and a write-protect switch are provided.

Key Features

The Rosemount 2240S data sheet lists the following capabilities.

• Temperature conversion accuracy of 0.05 °C supports precise inventory calculations and custody transfer.
• Up to sixteen 3- or 4-wire RTD spot elements can be connected to one transmitter.
• An integrated water level sensor input reports free water level at the tank bottom.
• Average liquid temperature is calculated from the individual spot values in combination with the radar level value.
• Ambient temperature effect is limited to 0.05 °C over -40 to 70 °C.
• Two-wire intrinsically safe Tankbus power and communication simplifies installation.
• Cryogenic sensor options cover LNG and other liquefied gases in full containment tanks.
• Metrology sealing and custody transfer type approvals are available for fiscal systems.

Industrial Applications

The Rosemount 2240S is used wherever bulk liquid inventories must be calculated accurately: crude oil export and storage tanks, refinery product tanks, aviation fuel farms, chemical and petrochemical storage, and refrigerated LPG and LNG tanks. Emerson also shows it in full containment LNG systems for average liquid temperature, redundant stratification monitoring, skin and cool-down temperature and leak detection. In Oman, these duties appear at coastal crude terminals, the refinery tank farms in Sohar and Duqm, and LNG and LPG facilities on the eastern coast. Operators upgrading older mechanical or manual systems can add the Rosemount 2240S tank by tank, because it shares the Tankbus with the radar gauge and needs no separate power cable, so the existing tank hub infrastructure is reused and the field wiring effort stays low.

Seven Star LLC supplies the Rosemount 2240S across the Sultanate of Oman and the GCC as part of complete tank gauging packages, together with instruments such as the Rosemount 3144P temperature transmitter and Rosemount 214C RTD temperature sensor for single point temperature, and the Rosemount 5408 non-contacting radar level transmitter for process vessels outside the fiscal tank farm.

Technical Specifications

The table below lists Rosemount 2240S data from Emerson product data sheet 00813-0100-2240.

How to Order

To quote the Rosemount 2240S, Seven Star LLC needs the number of spot elements, sensor model and length, water level requirement, hazardous-area certification and any custody transfer approval. Download the Emerson product data sheet from this page for your design package. Seven Star LLC supplies Rosemount tank gauging equipment from Muscat to terminals and plants throughout Oman and the GCC, with sourcing and model selection support.