One thing that we continually focus on are facts — and sadly manufacturer specs rarely seem to line up with real-world testing. So in order to provide you with the best information, we have invested in yet another piece of high-quality test equipment — the Monarch PT-99 Digital Tachometer.
The PT-99 is a very easy-to-use device that utilizes an optical LED beam (up to 36″ from an object). It reflects the LED off of a small piece of reflective tape & converts the data instantly onto the screen to show you what the “real-time” RPMs really are. In addition to this, it also has a memory setting which can report the min/max RPM readings also during testing.
Here are the specs on the PT-99:
- MADE IN USA
- Battery Powered (2 AA – Included)
- 60 Hour Battery Life
- Real Time, Min, & Max RPM Readings
- Trigger Lock/Unlock Modes
- Lightweight = 7oz
- Dimensions = 7″ L x 2.5″ W x 2″ D
- RPM Range = 5-99,999
- Accuracy Range = +/- 0.01%
- Max Distance = 36″ From Object
- 1/4″-20 Tripod Mount
Since the PT-99 can easily take measurements from basically any spinning object — this means that we will be able to include testing with cordless power tools, corded power tools, pneumatic tools, power equipment, & gas engines! As with most specs, we expect to see some big discrepancies between our results & those posted on the side of the box/tool.
For some quick tests in this initial video, we tested the following (with results) :
Milwaukee M12 Drill
- Advertised RPMs = Mode 1 @ 400 rpm / Mode 2 @ 1,500 rpm
- Actual RPMs = Mode 1 @ 383 rpm / Mode 2 @ 1,421 rpm
Husky Pneumatic Die Grinder
- Advertised RPMs = 22,000
- Actual RPMs = 21,062
RIDGID 15″ Floor Model Drill Press
- Advertised RPMs = 450
- Actual RPMs = 441
As you can see from results above, actual specs dont align with advertised ratings. Keep in mind that there are factors which can/will cause false results — and the testing environment needs to be verified (each time we test a tool). Having a fully charged battery is essential for cordless tools & having the correct “working PSI” is essential for pneumatic testing.
The Monarch PT-99 is very easy to use. We decided to buy it (even though it is more expensive than entry-level units) because it is Made in the USA, has a 1-yr warranty, has a VERY low margin of error, & came highly recommended from multiple tool design engineers. For the casual DIYer, this may be overkill…..but to get the most accurate results for you — it is the one we chose.