Thread: Laser Digital Tachometers - tried one?

There usually come with reflective stickers that you stick on the shaf for the laser to pick up on

bought one with stickers on ebay several years ago have not had any probs, had a mate who worked at BAS check it on a fancy machine it was accurate to to .4027 rpm

I've has 2 laser tachos like these and use them for lots of applications

Handheld LCD Digital Laser Photo Tachometer Non Contact RPM Tach Tester Meter I5 | eBay

Both checked against a calibrated frequency meter at work. They are accurate to < 0.1% so at 3000 RPM the accuracy is <3 RPM - it could have been more accurate than that but the calibrated source was only that accurate.

I bought the first one more than 15 years ago when they cost about $50 and after a couple of years I lost it so I bought an identical one for about half the original price. I see they are now as low as $10 delivered.
I had the second one for 4-5 years and meanwhile I found the first one and then gave the second one to a relative.

The first one still run off the original battery.

Both of mine came with a couple of strips of highly reflective self adhesive tape and you cut a thin strip off and stick it to any rotating part.

BTW sometimes a secondary reflection or bright spot or bright dark transition can fool the tacho into thinking there are 2 or more reflections on the rotating bit so you end up measuring double or more of the RPMs.
To check if this is a problem add a second strip, if there's no reflection the RPMs should double. If there are 2 or more reflections the RPMs wont double but will be less than double.

We have the older style photo tachometers and they work fine with a thin line of "White Out". Not sure if the laser units would work with "White Out" though.

The laser ones work off a pulse. If the rotating object is reflective then a black texta mark can sometimes suffice. If the object is dark then a bit of white electricians tape may suffice,