viscosity in SSU

[candystromvig]

when measuring viscosity in Seconds Saybolt universal does the temperature sample have to reach the test temperature? i know this sounds strange but the piece of equipment that i found in the lab consists of a water batha and a brass cylinder in it with the standard orifice at the bottom but there is no way to close the opening so that you keep you sample in the water bath till it reachings the test temperature. am i missing something?????
thanks