The First and Most Important Question To Ask is “Do you Only Want to Check RPM?” If the answer is “yes” then maybe you should buy an Optical Tachometer instead.
If your user cannot shutdown the rotating equipment to attach a piece of reflective tape for the Tachometer, then they must use a Stroboscope to read RPM while the device is running.
Many times users want to “Stop or Freeze” the motion for Diagnostic Inspection with a Stroboscope to view what is happening at that particular RPM or Flashes Per Minute (FPM).
Checking RPM of a rotating device with a Stroboscope is more complicated and takes practice as compared to using an Optical Tachometer. A Stroboscope will give the user more than (1) “stop motion” RPM readings and these are called “harmonics”.Harmonics are multiple single, double, triple, etc. “Stopped Motion Images” at various RPM or FPM settings.
Does Application Require“Contact” Tachometer to Read in RPM or Linear Speeds Such As a Conveyor Belt or
Elevator Speed in Inches per Minute, Feet per Minute or Meters per Minute?