Following high levels of demand, NEL’s density calibration service is upgrading the level of accuracy it offers by reinstating the Primary Densitometer in its facility.
“The Densitometer Calibration Facility has been very busy recently,” says Principal Consultant, Dr Norman Glen. “For example, last year we calibrated 95 customer densitometers and undertook five weeks of research on the density measurement performance of a new design of Coriolis meter for a major manufacturer.”
“There is a real depth of demand from industry for density calibration services,” he explains. “Many of the densitometers we see have been through our calibration facilities three or four times. We have also seen more interest from manufacturers of Coriolis meters for improved calibration of the density output of their meters. We are working with them to improve this aspect of their performance.”
To further improve the densitometer services on offer, work is underway to re-instate the Primary Liquid Densitometer at the lab. This nationally important project began in Dec 2017. When complete, it will re-establish traceability to primary standards for liquid density measurement at elevated temperatures and pressures. The project is scheduled to finish in May.
“This work has become a priority due to requests from meter manufacturers for enhanced density calibration services for next-generation density measurement devices,” Norman explains. “It will also meet the demands for enhanced accuracy at elevated pressures that our new era multi-phase test facility will bring.”
“Our approach uses Archimedes principle,” Norman says. “It measures the apparent mass of a reference body (made from fused silica) in the fluid that we are trying to determine the density of.”
At present NEL uses reference fluids to establish density and there is no direct chain of traceability to primary standards. The use of reference fluids adds an additional source of uncertainty. The completion of Primary Liquid Densitometer project will allow this uncertainty to be removed, resulting in lower overall uncertainties and improved measurements for industry.