The smartest test engineer

With an online quiz series that we began running on September 1 and that will continue until May 2005, we propose to identify the world's smartest test engineer.

That's quite a challenge, and when we succeed, I guess that will make us the world's smartest test-engineering magazine.

Despite the hyperbole of the quiz's title, the contest does invite reasonable questions about what constitutes an effective engineer. Perhaps, for production engineering, a good high-level definition is "the person who can achieve the minimum number of test escapes in the least amount of time at the lowest possible cost." For lab work, the world's smartest test engineer might be the one who can debug a prototype with minimal time and cost.

Would such a person necessarily be good at written examinations, or would someone with years of industry experience be more valuable? Is a good theoretical background helpful, or would extensive knowledge of available test tools be more useful?

There are no definitive answers to such questions.

Consider our September quiz, in which we asked participants to determine the resistance of a device under test in the presence of an in-circuit parallel network of two series-connected resistors. We presented a test network and described measured voltage and current values as well as test-circuit component characteristics. Then, we asked readers to provide the answer. (Visit www.tmworld.com/quiz_archive to see the circuit.)

There are several approaches to getting the right answer:

• An engineer with a strong theoretical background might eyeball the circuit and quickly note that the op amp will try to maintain both ends of resistor R_P2 at 0 V, from which he or she will deduce that all test current i _TEST flows through R_DUT, except for the measurement error-source current that flows through R_P2 because of op-amp offset voltage.
• Others might simulate the circuit or breadboard it.
• A well-read engineer might be clueless as to how the circuit works yet recognize that the test circuit employs what's commonly called an "ohms guard"—a search of the Test & Measurement World archives for that term would quickly yield sufficient instruction to permit a rapid calculation of the answer.

The best test engineers probably combine various theoretical and practical skills, and the most effective engineering departments probably combine diverse personnel with varying skill sets. Try applying your skill sets to the current quiz, at www.tmworld.com/quiz.

Contact Rick Nelson at rnelson@tmworld.com.