[AndrewCologne]

If you have a MM with dutycycle option its the better way IMHO, some people do like analog dwell meters and the way watching the needle fluctuating around the dutyclycle.
But be aware that when measuring DC you must connect the red wire of the MM to the vehicles ground and the black one to the connection of the test port. As the ECU does its pulse width modulation on the ground wire of the frequency valve.

You can check your proper connection when engine is running cold below 15°C where the open Loop mode forces the DC to run at 65%, .... also at 30% open throttle which does result in a DC of 65% as well.

When connection is correct and engine is warm, by adjusting the CO screw try to achieve an average DC of 45% at 950 RpM idle which matches to a CO of más on menos 0.5% and that's the ticket.