We report progress in testing a dynamic gravimetric standard using both steady and unsteady water flows. For steady flows in the range 10 kg/s to 60 kg/s, the difference between the dynamic standard and NIST s static primary standard was 0.015 % with a standard deviation of 0.033 %, To measure unsteady flows, we calibrated a rapidly-responding electromagnetic flow meter (EMF) using NIST s static standard and we measured the time delay between the response of the EMF and the dynamic standard. We also verified that the response time of the weigh scale was sufficiently insensitive to the load on it. For testing, the unsteady flows averaged 12 kg/s; however, these flows were either ramped or pulsed up (or down) by 5 kg/s. When integrated over the collection interval, the difference between the dynamic standard and the EMF was 0.008 % with a standard deviation of 0.012 %. This excellent agreement supports our model for the dynamic standard and justifies the further study of the dynamic standard, particularly at higher flows where the mechanical simplicity of a dynamic standard might reduce the cost of accurate measurements.
Proceedings Title: Annual International Symposium on Fluid Flow Measurement | 7th | | CEESI
Conference Dates: August 12-14, 2009
Conference Location: Anchorage, AK
Pub Type: Conferences
fluid flow, primary standards, dynamic standard