Step 1: Understanding the Concept:
The question asks to identify the device that is used for air pollution *monitoring* or *sampling*, rather than *control*.
Step 3: Detailed Explanation:
\[\begin{array}{rl} \bullet & \text{(A) Bag House Filter: This is an air pollution control device used to remove particulate matter from industrial gas streams by filtering the gas through large fabric bags.} \\ \bullet & \text{(B) Cyclone Separator: This is an air pollution control device that uses centrifugal force to separate particulate matter from an air stream.} \\ \bullet & \text{(C) High Volume Sampler: This is an instrument used for monitoring and measuring the concentration of particulate matter in the ambient air. It works by drawing a large known volume of air through a filter paper over a specific period. It is a sampling device, not a control device.} \\ \bullet & \text{(D) Electrostatic Precipitator (ESP): This is a highly efficient air pollution control device that removes fine particulate matter from a gas stream using the force of an induced electrostatic charge.} \\ \end{array}\]
Step 4: Final Answer:
A High Volume Sampler is used for sampling air pollution, not for controlling it.