ORIGINAL: ********
My Globee Tachometer when held up to a florescent light reads...
180 when set to 2 blades
120 when set to 3 blades
90 when set to 4 blades
The reading must be multiplied by 10.
Is this correct? I thought it would read 360 when set to 2 blades, etc.
Mike
It's playing off the power line frequency (60hz) that runs the lights. 60hz x 60 sec/min = 3600 cycles per minute. Divide by 2 blades = 1800 cycles per minute (or RPM in this case)