February 25, 2019 -- Emerson introduced a high-performance version of its Rosemount 3308 Guided Wave Radar (GWR) Wireless Level Transmitter, making it a standalone wireless radar level device to comply with the API 18.2 standard that provides guidance for crude oil custody transfer from small lease tanks. The transmitter – part of Emerson’s Plantweb digital ecosystem portfolio of technologies, software and services – delivers accuracy which can be verified without having to open a tank’s thief hatch, for safety.
An upgraded microwave module has made the Rosemount 3308 more tolerant to difficult process conditions and therefore able to deliver a more sensitive and repeatable measurement with accuracy. API 18.2 requires level transmitters to operate with 1/8 inch (3mm) resolution and 3/16 inch (4.7mm) measurement accuracy, which the Rosemount 3308 achieves when set up in high-performance mode.
This then enables it to achieve the installed accuracy of 1/4 inch (6.3mm) required to comply with API 18.2. In standard mode, the accuracy of the device has been improved to 1/5 inch (5mm).
Accuracy can be verified in just a few minutes using the Rosemount VeriCase mobile verification tool. This procedure does not require a tank’s thief hatch to be opened or any product to be transferred. Opening the thief hatch can cause high concentrations of hydrocarbon gases and vapors to be released, putting worker health at risk, so eliminating this requirement is an important safety improvement.
In addition to providing the accuracy required for custody transfer applications, the Rosemount 3308 also delivers readings for continuous level and interface monitoring applications in refineries, oil fields, offshore platforms and chemical plants, thereby providing a cost-effective standardized solution across an entire facility. The Rosemount 3308 is a top-mounted device that is virtually unaffected by changing process conditions such as density, conductivity, temperature and pressure.
For applications involving interfaces, the Rosemount 3308 helps to maintain product separation by issuing an early warning if an interface is identified where there should be only one liquid.
