An Improved High-Precision Calibration Procedure For Reference Standard Hydrometers

This pape r describes a me thod of calibra ting hydromete rs whic h. a lthoug h no more accurate tha t the technique used he re tofore at the Na tiona l Burea u of S ta nd a rds, reduces calibration time from se ve ral days to a few hours. The p rocedure is based upon eas ily measured h yd rome ter we ight , s tem sca le geometry, and flotat ion leve l measurement s a t onl y one liquid density. The reliability of thi s s ingle leve l is improved by o bse rving the hydrome te r Rotation und er va ri ous we ight loads. The ca libra ti on ex pe riment is o ri en ted toward aut omati c data reduction so the fini shed ca libra ti o n report is of much wide r app li ca bility than the s imple co rrection ta ble de rived fro m t he old er experim e nt.