DT-205LR-S12

Easy to break

Exactly what I expected.

I was hesitant at the price of this unit as it is expensive. However I decided that on most tools you get what you pay for so I purchased this unit as I needed an accurate measurement for my marine Diesel engines. After reading the directions and following, I initially used a (recommended) "small piece" of supplied reflective tape to the crank dampener. After much frustration of getting very consistent (still jumpy but got the same readings consistently) but very inaccurate rpm's, I thought that the tape was potentially too small so I applied about a 1 inch piece on it. Same exact results. Then I closed the engine hatch making it darker thinking possibly too much ambient light. Only then could I get accurate results but very inconsistent! Most of the time it read the same as before. Mid 1600 rpm. I have digital tach's and they read 820's. (I was only trying to test the unit with a known rpm). I could only get very the true rpm for only a few seconds then it would jump back to inaccurate high readings. Then I figured I would try the contact wheel. Wow was this inaccurate. I switched the setting over to contact rpm and tried it. It then read the rpms were 16000 plus! Yes thousands!! So be warned about this unit. I should have been concerned when I could not find a single review on it!