NEIKO 20713A Digital Tachometer, Noncontact Laser Photo Sensor with 2.5 to 99,999 RPM Accuracy, RPM Gauge Marker with Batteries Included

I bought this particular tachometer, because I own several tools made by Neiko, and they're quality tools. I used it to test my new 1.5kw spindle motor and vfd.It's important to use a small piece of the reflective tape on whatever you're testing. The tape wasn't sticking well to the spindle motor, because of the packing grease. Even after cleaning the collet chuck, it came off. So, I put a piece of non reflective tape on the chuck, and a small piece of the included reflective tape on top of it, and it's still holding.It was with the Neiko tachometer that I discovered that my new vfd display wasn't defaulted to rpms. That sounds like something that would be obvious, but my vfd reads out "r" before frequency, not rpms, so I thought r240 was 24000 rpms; it was a frequency of 240 (go figure). When I realized what was going on, I was able to correct the vfd programming so that it defaulted to rpm readout. I found that the vfd was correct to minus 35-50 rpms. The Neiko reading was rock solid, and consistent through 6 different spindle speeds. I didn't find a difference in reading based on distance from the source; the reading was the same whether taken 4" away, or 4' away.It came with a battery, which worked. But, I prefer a good alkaline battery over a mercury battery, so I'm storing it with a 9v alkaline. I do not store my battery operated tools with batteries inserted; I store the batteries with them, but not inserted.The storage pouch is nice. I'm storing the tachometer in the cnc table drawer. The neiko tachometer came with a zippered pouch, quite a bit of reflective tape (I'm only using about 3/16"), a 9v battery, and instructions.

Functions as it should.Some reviewers complained about overheating, but that's how it works. There is a small heat element that is used to test the battery under LOAD. It glows red. That's why they have a 10 second time limit.

Purchased to check propeller rpms on my RC motor test stand. Indoors so lighting was led shop lights but that shouldn't matter because the unit has it's own red led built in. Worked great on wood or black nylon props but seems unable to "see" the grey APC style ones. Perhaps a black sharpie might help. Also, store with battery removed. It appears to have an auto shutoff feature but mine killed the battery after 3 or 4 days of my not being aware it was on. Works great as best I can tell though!

I used this to test my turntable and wood lathe. It does the job.

Easy to use,

Works as expected

I purchased two of these, five months apart after having misplaced one. I needed it for my router, since I was starting to use larger bits which have a lower max rpm speed. I had initially set it up, following the critical directions for the reflective tape, carefully placing it on the router shaft. Since the shaft was also a polished metal surface, I painted the shaft flat matte black, then affixed the reflective tape to one half only, hoping to provide the best contrast possible. On using it again, it remained a bit more steady, but would jump over multiples of the set speed. (My router has a constant speed setting despite variable loads). Still, when set at 8000 rpm, it would display every second, but rarely the same speed on consecutive seconds, and the variations would sometimes triple the speed. With the speed audibly constant, the tachometer reading still jumped around. After misplacing it, and it not reappearing for 4 months, I bought another, same brand and model. I wasted another afternoon, this time, painting one half of a large router bit reflective silver, the other half black. Same results followed. It is so variable, that I concluded it was a real danger to me to use, since a 2" router bit with a max RPM of 20,000, cannot be trusted to a tachometer which reads 12,430 when the router setting is for 20,000. Far more dangerous to have a bit spinning at 25000, rated for 20,000, when the "highly accurate" tach shows 13,546. I'm not going to risk selling this to someone else, and it's beyond the return window. I'll keep the 9v's for something else.