What kind of lamp to use with a stroboscopic disc?

If you have a Smart Phone, there are many light strobe apps that you can download for free

On my iPhone 6 Plus I use the app StrobeLight by Motionics.  You can adjust the speed of the strobe so it is very helpful

@miner42 
Would you be so kind as to walk me through how to use that app with a turntable? The documentation is pretty thin. Thanks!

You will need a turntable strobe strobe disk.  The markings will be set for either a 50hz or 60hz line frequency depending on your country's power supply.  In North America, we have 60hz power.  Just set the StrobeLight at 60hz and point it at the revolving strobe disc.  When the table's speed reaches 33.333RPM, the strobe lines will appear stationary.

Thanks for telling us about the app, brf.  I would never have thought to check for an app.  If you are too non-tech to go that route, the no-brainer solution is to buy the hand-held, battery powered strobe from KAB.  Along with their strobe disc, you will have a very accurate estimate of speed.  The others are correct to say that depending upon a steady 60Hz AC line frequency powering the bulb is chancy.