Emerson gets NMi approval for flowmeters for cryogenic custody transfer

Source: ControlGlobal.com

Oct 02, 2006

Micro Motion Coriolis FlowmeterBOULDER, COLORADO (October 2, 2006) -- Emerson Process Management announces that Micro Motion meters have been certified by the Nederlands Meetinstituut (NMi), and approved for custody transfer measurement of cryogenic fluids, such as Liquid Natural Gas (LNG). The cryogenic measurement accuracy of better than 0.5% certified by NMi far exceeds the maximum permissible error of 1.5% for cryogenic applications. This level of accuracy is achieved by sophisticated, patent-pending algorithms and advanced meter design that mitigate the dynamic relationships between super-cold process fluids, highly sensitive measurement technologies, and carefully-selected materials of construction.


The new approval comes as a result of a battery of rigorous tests recently performed in Dordrecht, The Netherlands and at the NIST facility in Boulder, Colorado. Under the careful scrutiny and assistance of NMi Certin B.V., preconfigured Micro Motion Coriolis meters were calibrated with water under calibration laboratory conditions, then tested for performance accuracy on oil at -20 ºC and -33 ºC, and liquid nitrogen at -193 ºC (-380 ºF) without any subsequent adjustments to calibration. A key requirement of the tests is that no configuration or electronics adjustment is permitted to be performed on the factory-configured meter—the stated accuracy must represent the out-of-the-box capabilities of the device as received from the factory.

The tests proved that the Micro Motion flowmeters perform within specified accuracy; with the mass flow rate of oil at -20 ºC and -33 ºC the observed error did not exceed 0.05%. For liquid nitrogen, the errors did not exceed 0.3%. The 0.3% accuracy without any adjustments from the original water calibration was sufficient to convince NMi that the meters would easily perform as delivered to within 0.5% accuracy, three times better than the maximum permissible error of 1.5% required for cryogenic applications.

“The result of 0.5% mass accuracy is unique and not available from any other Coriolis device or other technology flowmeter” says, Aart Pruysen, European Emerson Process Management Approval Director. He adds, “Emerson has shown innovative technology now validated for cryogenic (LNG) applications, with the added benefit of no need to prove Micro Motion Coriolis meters at operating conditions. These results are unprecedented and unique in the custody transfer arena and could save the customer proving costs.”