A wide-range (up to 1010 P) rotating cylinder viscometer

1~he ra nge of a hi g h temperature rota Ling cylinde r v iscometer has bee n extended so t hat VISCOSIty m easuremen.ts can be m ad e betwee n 10 0 to 10 10 p oises to within 2-p ercen t a ccuracy. ThiS lllvolves three different tec hniques . After a calibration consta nt has been determined for the apparatus III the stand ard oil range, the other two constants for t he hi g her viscosit ies \-v ere se lf~d etermlll e d . In ma klllg measurements at t he low viscosities, 10 0 to 10 5 poises, the o~ter e~l~nd e r J 7 S, ro t.ated at co ns tant sp ee ~ a nd the torque measured on the inner cylinder ; flO~ 10 to 10.' pOIses the 111l1 ~1~ cyll11der IS rotated t hrough a n a ngle a nd timed as i t r eturns ~o Its zero pOSitIOn, and fr~m 10. 0 to 10 10 poises the inner cy ~incl er is drive n t hrough a n a ngle at co nstant to rque and tuned as It traverses t hiS a ng le. fhc Fulcher equation viscosity va lues obtall1ecl from prevIOus m ~as ur e m e nts on Stan da rd Glasses No . 710 and No. 711 by t h e fiber elongat ion a nd rotatmg cylmclcr methods have been compared with the presen t results.