Process Control And Instrumentation

Step 1: Recall accuracy definition.
Accuracy = error specified as a percentage of true value.

Step 2: Calculation.
If specified accuracy is of full scale, then at of full scale: So the instrument error is relative to the measured value.

Step 3: Conclusion.
The correct answer is (D).

Step 1: Understanding instrumentation costs.
In a modern chemical plant, the cost of instrumentation is generally a small portion of the total plant cost, typically ranging from 1.5% to 10% of the total cost.

Step 2: Explanation of options.
- (A) 1.5 to 10% is the typical range for instrumentation costs. - (B), (C), and (D) These values are too high for instrumentation costs, as they do not exceed 10% in a typical plant.

Final Answer:

Step 1: Match terms with correct properties.
- Lag refers to delay, hence associated with Speed of response (I).
- Static and dynamic error represent the difference between input and output, hence linked with Fidelity (II).
- Drift represents a slow change in measurement over time, hence related to Reproducibility (III).
- Sensitivity refers to the ability to detect small changes, hence matched with Precision (IV).

Step 2: Verify mapping.
Therefore, the mapping is: A I, B II, C III, D IV.

Step 3: Conclusion.
The correct answer is (A).