We describe a new dynamic, gravimetric, liquid flow standard (LFS) that determines flow by measuring the rate of change of the liquid mass accumulating in a collection tank. The LFS is a fully- automated,15 kg/s system that uses a proportionalintegralderivative (PID) control loop to achieve liquid flows with a stability that is the smaller of 0.001 % or 0.1 kg/s. The expanded uncertainty (corresponding to 95 % confidence level) is 0.021 % for the flow range of the standard; 15 kg/s to 0.22 kg/s. We verify the uncertainty budget by comparing the LFS results with two well-established NIST primary flow standards.
9th International Symposium on Fluid Flow Measurement
April 14-17, 2015
dynamic liquid flow, liquid flow primary standard, gravimetric standard