Patent ID: 8415582

Claim:
A method of monitoring and maintaining a weld cap which is executing successive resistance welds on a plurality of workpieces, the method comprising: measuring a first weld indentation formed during a first resistance weld; comparing the measured first weld indentation with a severe threshold; when the measured first weld indentation is greater than the severe threshold, signaling an abnormal condition; tip dressing the weld cap based upon the signaled abnormal condition; measuring a second weld indentation formed during a second resistance weld; comparing the measured second weld indentation with the severe threshold; when the measured second weld indentation is greater than the severe threshold, signaling the abnormal condition; recording a time lapse between the first resistance weld and the second resistance weld; determining a degradation rate between the first resistance weld and the second resistance weld, wherein the degradation rate is the time differential of the measured first weld indentation and the measured second weld indentation; and when the abnormal condition is signaled, choosing one of a first tip dressing schedule and a second tip dressing schedule based upon the determined degradation rate.