strobe light question

I have a Oracle Delphi MK II
It has 2 screws in the back for 33rpm and 45 rpm.
Is the 33 rpm actually 33 1/3 rpm?
I want to check the speed to make sure its dead on.
Is there a commercial product strobe light like auto mechanics use that would work?
It seems it may be cheaper to buy one of these.I dont want to spend alot to check the speed once.
I would rather put my faith in a lava lamp :o)
Tim,buddy! Get into analog yet?
This methold could cost you nothing and is very accurate. You'll need two pieces of tape (use a type that leaves no residue) and a stop watch/timer. Place one piece of tape on the platter and the other on the plinth. Place a record on the platter, start the turntable and use the tape markers to count the platter's rotation. In 3 minutes you should count exactly 100 revolutions. For even greater accuracy count for 6 or 9 minutes, or even longer. It's tedious, but it works.
Thank you 61.I'll give it a try!
The best strobe and timer record I have sceen is the KAB Speedstrobe. It retails for around 100.00 from Music Direct. I have used mine for a couple of years with a VPI SDS and my turntable speed is dead on 33 1/3/and 45.
David, for almost no cost find an LP with speed bars. The M&K Realtime Direct to Disc and many audio "test" discs have this imprinted on the record label. A small neon night light from Radio Shack works perfectly as a strobe source.

I used this at a friends house recently and when I went back to verify with my KAB, the speed was perfect.