hello

what is the easy way to see rpm in picoscope 6 automotiv?
i don`t find any?

regards
mathias

When you drag in the vertical cursors, RPM and frequency appear in a small box in the lower right hand corner. It's a bit tricky, as it's calculated on time, not as a direct measurement, such as an inductive pick-up, so you can measure anything, and it'll give you an RPM calculation. If you measuring a cam signal, for example, you'll measure cam RPM, which equals 1/2 crankshaft RPM. If you use secondary ignition to calculate RPM, make sure you are on 2 power strokes, not a power and a waste (DIS system).

hello

thanks Mike

regards mathias

Mathias,

Here is an image measuring engine RPM by framing one crank revolution with the vertical rulers.


Quote:

If you use secondary ignition to calculate RPM, make sure you are on 2 power strokes, not a power and a waste (DIS system).

Mike, would you not want one ruler on power event and one on waste?  That would be one crank revolution right?  Of course, you could measure two power events and then multiply the RPM result by 2 to get engine RPM.

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Tom Roberts wrote on Mar 21^st, 2010 at 8:12am:

Mathias, Here is an image measuring engine RPM by framing one crank revolution with the vertical rulers. Quote: If you use secondary ignition to calculate RPM, make sure you are on 2 power strokes, not LIKE a power and a waste (DIS system). Mike, would you not want one ruler on power event and one on waste?  That would be one crank revolution right?  Of course, you could measure two power events and then multiply the RPM result by 2 to get engine RPM.

Tom

I was going to respond to Mike about this untill I added the word LIKE after the word NOT :D

Mick

Right guys, my mistake. Thanks. :)

Basically all that rpm tells you is how many times the time period between the rulers will go into a minute or the frequency per minute of that time period.
In other words it multiplies  time period HZ or time period frequency per second by 60.
 It only tells the actual engine rpm when you have a known 360 degrees of crank time framed like Tom's example shows.
 I wouldn't pay much attention to it as you get used to using the scope you'll find it's relatively quick to find rpm from about any two signals you see once you know the frequency per revolution.
 Using that all the time to find rpm kind of locks you out of seeing speed changes during the course of a revolution.