I have to work on a few older tractors that my timing light won't pick up so I can't use it for a tachometer to get accurate RPM's. So, what is an accurate non contact tachometer. I saw the Snap-On one in the flier but I am not yet sold.
http://www.ebay.com/itm/Digital-Las...hash=item20c0628470:m:mLo41C8sTMQey8uXCveMR4Q
I have this. It comes with a little case and quite a bit of retroreflective tape so it can pick up a tach signal. It works scarily good, to the point where I can get a tach reading over 6 feet away from whatever I'm measuring.
I checked the accuracy against a 60Hz strobe, and it read dead-nuts 3600 RPM, which is exactly what it should.