Saybolt viscometer is used for empirical measurement of viscosity
of transparent and opaque lubricant and residual liquid oils,
mostly electrical insulating oils of mineral origion at specified
The viscometer is calibrated at regular intervals by measuring
the efflux time at 100 F of viscosity standard. If efflux time differs
from certified value by more than 0.2% then correction factor is
calculated as F = V/t
*Say bolt viscometer and bath
*Timer (graduated in 10th of second and accuracy
*when tested over 60-min intervals)
1) The sample was preheated below the flash point.
2) A cork stopper having a cord was inserted into the chamber
at the bottom of viscometer to prevent the air escape.
3) The sample was filtered through 100 mesh screen directly
into the viscometer until the level approached to the overflow
4) The viscometer was constantly stirred by the thermometer
for 1 min until the temperature become constant.
5) The oil was removed until its level reached just below the
overflow rim with help of withdrawal tube.
6) °the receiving flask then was placed under the viscometer.
At the same time, the timer was allowed to start as stopper
was removed by cord until the flask filled to the mark.
7) The experiment was repeated at different temperatures.
Initial temp. 20°C
Final temp. 50°C
Sr. Temperature(°C) Time(second)
1 20 2min-20sec
2 30 1min-24sec
3 40 1min-12sec
4 50 1min-5sec
Temperature and viscosity have inverse relation.