ProtmexDigital Tachometer, 50-99,999 RPM High Precision Laser Photo Tachometer, Max/Min/AVG Data Hold Functions Rotation Speed Meter, PT6208B with Reflective Tape (Batteries Included)

Works great, I also purchased the manual operated contact model, which also works very well. Quite handy to have around the shop!

A newly-installed (electronic pulse driven) tachometer proved to be wildly inaccurate. This product allowed me easily to calibrate it. (1) Set the engine to a comfortable RPM above idle. (2) Check actual RPM at the crankshaft pulley. (3) Adjust the tach to match. (4) Repeat to confirm settings.

I am finding the unit is a bit hit and miss at collecting speeds.

I bought this unit after I returned one that was about $10.00 cheaper, but didn't work. This unit gives me very accurate RPM readout when reading spindle RPM on a CNC mill equipped with a spindle encoder and RPM readout.RPM comparison to the CNC mill readouts were within 1% or better. I highly recommend spending the extra $10.00 for this unit.

Right out of the box I tried to test it on my cordless drill. Used the shiny tape and everything, it either wouldn't read at all, or would say my drill was running at 87,000 rpm when it was on low speed. I thought maybe light was interfering , but I went into a totally dark room and got the same- drill was either reading at 90000 or 55000 or 0 or about 1 of every ten tries, it would read correctly at 400 rpm. No worky worky, sending back. Bought this to test my CNC spindle speed, and it won't work at all.