Measuring RPM with a DVOM

[Shorebum]

Anyone ever heard of setting a DVOM to HZ scale and measuring frequency to convert to RPM? If so how would you do this?

 

[smokeonthewater]

Re: Measuring RPM with a DVOM

for starters you'd have to know how many pulses per revolution... IE 12 pole alternator would be 6p/r.... soooooo 100hz would be 1000 rpm

 

[Shorebum]

Re: Measuring RPM with a DVOM

Ok, I want to try this on a 2000 Johnson 130. I believe these are 12 pole systems meaning a 6P setting at the tach. Where would you take the measurement? The gray tach wire from the rectifier? Also hertz are per second so.... to get RPM multiply by 60...

 

[smokeonthewater]

Re: Measuring RPM with a DVOM

I'd say yes tach wire and ground


I knew something was wrong when I posted it but I'm SLEEPY lol... I fixed it I think:facepalm: