Makes Up For It With Enthusiasm
As the title says - anyone have recs for a remote tachometer I can use to verify my tach readings? Looking on Amazon they seem to range from $20-200 and I'm not sure what I'm looking at, to be honest.
Can you provide the name of the app? IPhone or Android? It sounds interesting.I replaced the tach on my Yanmar 3GM30F a few weeks ago. The old OEM tach used a magnetic sender on the transmission bell housing. The new tach runs off the Balmar alternator I installed a few years ago. Not having a digital tachometer handy once I had everything installed, I was curious to see if there’s any apps that could help me at least get in the ballpark with calibration of the tach. To my surprise, there’s a few apps - some work using the phone’s light and camera, others use the microphone and an algorithm to analyze the engine sound patterns at idle. Out of curiosity, I tried the latter. It came in at 860 rpms, in the range specified by the manual. So I set the tach to that. Then increased to 2500 rpms. The app detected the change and matched to within 5-10 rpms. I’ll probably still get something more accurate later, but it’s good enough for now to get me out sailing.
I have had very good experiences with the Neiko 20713A Digital Tachometer. I tested it on various things off the boat with a known RPM and it was accurate. It is very easy to use, and reports a minimum, maximum, and mean for the period of time that you point it at the rotating shiny thing and hold the button. My experienced local diesel mechanic was initially suspicious of the ~$20 Neiko until I used it to demonstrate that the tachometer his technician had been using to test my driveshaft RPMs was inaccurate.
Neiko 20713A Digital Tachometer, Non Contact Laser Photo | 2.5 - 99, 999 RPM Accuracy | Batteries Included (Renewed): Amazon.com: Industrial & ScientificNeiko 20713A Digital Tachometer, Non Contact Laser Photo | 2.5 - 99, 999 RPM Accuracy | Batteries Included (Renewed): Amazon.com: Industrial & Scientificwww.amazon.com
I was too brief, sorry. The tachometers that I have used detected that the fluorescent light is the source of the strobing. It then reads in hertz, or 60. The tachometer’s usual internal light in normal operation (most are infra red) is reflected off the single piece of tape in normal operation. My cheap(ish) one reads 60 when pointed a a fluorescent light as well. If I could find it, I could tell you which model it is, but it is about 20 years old, and likely out of production anyway.IIRC that requires you to get the engine to 3600 RPM (not possible on most of our Diesel engines) or 1800 RPM would cause two stationary reflections to show up 180 degrees apart if used with the tape as shown in my picture right?
You can always verify a optical tachometer. Point at a fluorescent light. The fluorescent light is blinking at Exactly 60 cycles per second in the USA. So you should read 60. This is a cal feature on lab grade ones I used to use.