Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I just got one of these Vibra Tachs.  I need it to measure rpm on my diesel power plant.  I have the instructions and read them but I'm still not clear on it's operation so these are a few questions to those who have used one. 

Do you hold the device on a flat part of the engine and slowly turn the inner ring until the wire comes out far enough to start to vibrate?  If you go further out does the wire stop vibrating?   How much of a vibration arc does the wire achieve?  Less than a quarter inch? eighth inch?  etc...   Any help will be appreciated. Thanks.

elbrecht wrote:

That's an interesting point Jim.  The instructions say that in some instances where there are more than one rotating part (i.e. gears)  it may not read accurately.  However, I'd be willing to bet that it might be able to read the impeller if you place it on the impeller housing ensuring that you keep it as far away as possible from the auger.  Be very careful working around the moving parts.   I'm going to give it a shot on my machine once it warms up a bit.  It's been minus 20C here for the last couple days and down to - 39C with the windchill.