Uni 3220 (LATEST)

The verdict: The Uni 3220 offers 90% of the Fluke's accuracy for 30% of the price. It is the "sweet spot" for serious DIYers and professional maintenance crews. Problem: Screen shows "0" or "---". Fix: You missed the tape. Angle the laser slightly so it hits the path where the tape will be, not where it currently is.

You stick a small piece of reflective tape (included in the box) onto the rotating object. The laser shines at the tape. Every time the tape passes the laser, the sensor counts one rotation. In one second, it knows exactly how fast the shaft is spinning. Step 1: Prep the Target Cut a 12mm square of the reflective tape and stick it to the rotating surface. If the shaft is black or dark, the reflection works best. For shiny metal, you may need to put a piece of black tape down first, then the reflective tape on top.

Numbers keep jumping (e.g., 1500, then 3000). Fix: The sensor is seeing double reflections. Move the unit closer or cover any shiny surfaces behind the shaft with black electrical tape. Final Verdict The Uni 3220 is a workhorse. It isn't fancy, it doesn't have Bluetooth, and it won't log data to an app. But it will tell you exactly how fast something is spinning within +/- 0.05% accuracy every single time.

This compact, laser-guided tachometer allows you to measure Rotations Per Minute (RPM) from a safe distance. Whether you are an HVAC technician diagnosing a faulty blower or a hobbyist balancing a CNC spindle, here is everything you need to know about the Uni 3220. The Uni 3220 is a non-contact digital tachometer. Unlike old-school mechanical tachometers that required physical contact with a spinning shaft, this device uses a visible laser beam to measure reflective pulses.