Abstract: A gage for quickly testing complex articles for conformance to a standard comprises a fixture configured according to the standard for holding the article and clamping the article into engagement with bearing surfaces. The bearing surfaces are instrumented with force sensors so that articles that deviate from the standard will produce force signals deviating from standard signals. A programmable controller quickly evaluates the signals to accept or reject the article.

Abstract: The inductors in an induction heating apparatus are arranged in parallel branches with an SCR in series with each inductor and an RC snubber circuit in parallel with each inductor. If an SCR becomes shorted the faulty SCR is detected by a method and apparatus for coupling a capacitor across the inductors one at a time, exciting the capacitor-inductor circuit with a frequency suitable to induce a resonant condition provided the inductor is in series with a normal SCR and whereby resonance will not occur if the inductor is in series with a shorted SCR, and sensing circuit resonance thereby detecting whether the SCR in series with the selected inductor is shorted.