Question

Which comparator type uses a dial indicator to measure deviations from a standard?

• A. Optical comparator
• B. Mechanical comparator
• C. Electronic comparator
• D. Pneumatic comparator

Hint:

Dial indicators, Johansson Mikrokator, and Sigma comparators all rely on gears, levers, or steel strips for magnification.
Hence, they are all classified as mechanical comparators.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks to classify a comparator that utilizes a dial indicator to measure geometric deviations from a predefined reference standard.

Step 2: Key Formula or Approach: This is a standard classification question in metrology. Comparators are categorized based on the physical principles used to magnify the displacement of the measuring plunger: mechanical, optical, electronic, or pneumatic.

Step 3: Detailed Explanation:

• A comparator is a precision instrument used to compare the dimensional differences between a workpiece and a known standard block (such as slip gauges).

• A dial indicator (or dial gauge) is a classical measurement device that utilizes a rack-and-pinion gear mechanism to convert the linear movement of a contact plunger into the rotational movement of a pointer over a calibrated scale.

• Because the magnification and pointer movement are achieved entirely through mechanical links, gears, levers, or springs, a dial indicator falls directly under the category of a Mechanical Comparator.

• Other types use different mechanisms: optical comparators project light reflections; electronic comparators use electrical changes (like LVDT); and pneumatic comparators utilize back-pressure of compressed air.

Step 4: Final Answer:
The comparator that uses a dial indicator is a mechanical comparator.