Question 544General Subjects - Assistant Engineer

The correct answer is B) 0°F. In a pneumatic transmission system for instrumentation, the transmitted pneumatic signal pressure is typically in the range of 3 to 15 psig, with 3 psig corresponding to the lower end of the calibrated scale and 15 psig corresponding to the upper end. Since the given calibrated scale is -40 to +40°F, and the transmitted pressure is 9 psig, the actual measured temperature would be the midpoint of the scale, which is 0°F. The other options are incorrect because: A) -10°F would correspond to a lower pneumatic signal pressure, around 4.5 psig. C) +10°F would correspond to a higher pneumatic signal pressure, around 11 psig. D) +25°F would correspond to an even higher pneumatic signal pressure, around 13.5 psig.