Noncontact displacement sensing: among common displacement transducer families, do optical and capacitive types qualify as noncontacting measurement methods?

Introduction / Context:
Displacement transducers convert movement into an electrical signal. Some require mechanical contact (e.g., LVDT with core coupling; potentiometric sliders), whereas others can sense position without physical contact, which is advantageous where wear, friction, or contamination are concerns. This question asks specifically about optical and capacitive types.

Given Data / Assumptions:

• Optical displacement sensors use reflected or interrupted light.
• Capacitive displacement sensors measure changes in electric field/capacitance with gap variations.
• We are evaluating contact requirement, not range or accuracy limits.

Concept / Approach:
Optical sensors (reflective, triangulation, laser, encoder-based) measure position by analyzing light without touching the target. Capacitive sensors form a capacitor with the target as one plate; changes in distance change capacitance—again without contact. Both are widely used where noncontact operation is required. Contacting sensors (e.g., potentiometers) rely on mechanical contact and thus are not in this category.

Step-by-Step Solution:

Verification / Alternative check:
Product literature for optical triangulation and capacitive displacement probes emphasizes noncontact measurement benefits such as zero wear and minimal loading of the moving element.

Why Other Options Are Wrong:
Limiting to only one technology is false; both are noncontact. The 10 mm constraint is arbitrary and technology-dependent; noncontact behavior does not require a minimum gap of that value.

Common Pitfalls:
Confusing LVDT (inductive, often noncontact core coupling) with optical/capacitive; assuming capacitive sensors must touch the target—they do not, though standoff gaps are small.

Final Answer:
Applies