Posted by(작성하신 분) manav ( February 06, 2003 at 15:32:45: )
In Reply to(원문) : Redwood Viscosity - Redwood Viscometer
posted by(원문 작성자) : Rex on July 03, 2000 at 15:01:58:
: 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