Posted by(작성하신 분) suren ( June 16, 2001 at 18:01:48: )
In Reply to(원문) : Re: Redwood Viscosity - Redwood Viscometer
posted by(원문 작성자) : nbl on October 06, 2000 at 20:16:55:
: : Dear colleagues,
: : [Principle]
: : Ther's no scientific definition, unlike the Sybolt Universal Viscosity seconds(american standard)using an orifice hole, the Redwood
: : viscometer(english standard) uses an agate tube outlet instead and measures the time required to flow through the conduit for 50 ml in
: : seconds. Developed by Redwood in 1885, copied from that of Charles Rumble in the late 19th century.
: : Thesedays it seems not many people use the Redwood viscometer , instead in most cases one uses the Saybolt Viscometer. In korea
: : and united states most chemical and oil companies use SUS(Saybolt Universal Seconds) for the custody transfer purposes.
: : The instrument consists of a silvered brass container of 1 7/8 inch in diameter by 3 1/2 inch in depth. A i inch tube projected at an angle
: : of 45 degree closed at the lower end of the bath near bottom. This is one of the efflux time measuring viscometers.
: : [Conversion between Kinematic Viscosity and Redwood Seconds]
: : The conversion factor reported is as follows;
: : kinematic viscosity (in St, not in cSt ) = 0.00260 t - ( 1.88 / t )
: : where t is Redwood seconds.
: : Please refer to the following data reported in elsewhere(1).
: : reference :
: : (1) W.H.Herschel, "The redwood Viscometer", Technology Papers of the Bureau of Standards, Washington, August 5, 1921