If you need a portable, handheld tachometer, take a look at the HT-4100 from Ono Sokki Technology. This completely ergonomic device weighs less than 4 oz, so it slips right into your pocket. Setup is easy. Users simply apply a small piece of reflective tape or a dab of reflective paint to the surface being measured. Then, they aim the HT-4100's red light beam at the marker. An on-target indicator light flashes when the tachometer acquires the target.
The light beam has a 12-in. range for fast and safe measurements with 1-rpm accuracy. The HT-4100 can measure up to 50,000 rpm. An easy to read LCD display provides results. Every second, the device updates the rpm count. Three AAA batteries power the HT-4100 for up to 20 hours of continuous use.
For more, see www.onosokki.net.