Topic: Metrology and Inspection
The missing distance between A and B in the pin figure shown below is (GIVEN: Total length = $45 \pm 0.5$, segments = $30 \pm 0.2$ and $13.2 \pm 0.5$)
- A. 1.8
- B. $1.8+1.1$
- C. 0.6
- D. $1.8\pm1.2$
Answer: D. $1.8\pm1.2$
Explanation: The basic size of the missing section AB is the total basic length minus the sum of the known internal segments: $45 - (30 + 13.2) = 1.8$. According to the worst-case method of tolerance accumulation, the total tolerance is the sum of the individual tolerances: $0.5 + 0.2 + 0.5 = 1.2$. Therefore, the dimension of AB is $1.8 \pm 1.2$.