When fitting new contact-breaker points in the distributor, The normal way of checking the gap between them is with a feeler gauge. Points that have been in use for some times develop a Peakon one face that corresponds with a crater on the other, Caused by spark erosion as the points open. When this happens, A feeler gauge no longer gives an accurate measurement of the gap. A dwell meter measures the angle of rotation of the cam through Which the points are opened and closed, And registers the dwell angle – the period when they are closed. Using a dwell meter It can, therefore, be used to check the gap on worn points with More accuracy than a feeler … Continue reading Checking the dwell angle