Review on 🔢 Shimpo DT 205LR Non-Contact Tachometer - 6 to 99,999 RPM by Zack Frazier

I doubted the price of this device as it is expensive. However, I figured that with most tools you get what you pay for, so I bought this unit as I needed an accurate gauge for my marine diesel engines. After reading and following the instructions, I first attached the (recommended) "small piece" of the supplied reflective foil to the crank damper. After getting very frustrated with getting very stable but very inaccurate curves I thought the tape might be too small so I glued a piece of about 1 inch on top. Exactly the same results. Then I closed the engine hatch and made it darker, thinking maybe too much ambient light. Only then was I able to get accurate results, but very consistent! Most of the time it reads like it used to. Mid 1600 rpm. I have a digital tach and they read 820s. (I was just trying to test a device with a known RPM). I was only able to get very real RPMs for a few seconds, after which it would revert to an inaccurate high reading. Then I decided to try the contact wheel. Wow, that was inaccurate. I switched the setting to contact speed and tried it. Then he read that the RPMs were 16,000 plus! Yes, thousands! So be careful with this device. I should have worried when I couldn't find any reviews about it!