Question 548General Subjects - Assistant Engineer

70% to pass

If it is desired to determine the temperature difference between two locations using thermocouples, what wiring technique can be used to accomplish this?

AThe two thermocouples would be wired in series-opposing to measure the difference between the two temperatures.
BThe two thermocouples would be wired in parallel to measure the differences between the two temperatures.
CThe two thermocouples would be wired in series-aiding to measure the difference between the two temperatures.
DIt is not possible to measure a temperature difference using two thermocouples.
AI Explanation

The correct answer is A) The two thermocouples would be wired in series-opposing to measure the difference between the two temperatures. When using two thermocouples to measure a temperature difference, the series-opposing wiring technique is the correct approach. In this configuration, the thermocouples are connected in series, but with their polarities reversed. This allows the voltage outputs of the two thermocouples to oppose each other, resulting in a voltage difference that is proportional to the temperature difference between the two measurement locations. The other options are incorrect because: B) wiring the thermocouples in parallel would not provide a temperature difference measurement, C) wiring them in series-aiding would simply add the voltage outputs, not measure the difference, and D) it is indeed possible to measure a temperature difference using two thermocouples with the proper series-opposing wiring.

Want to practice with timed exams?

Download Coast Guard Exams for the full exam experience.

Get the App