Which practice is effective for mitigating ground-loop noise in instrumentation loops?

• A. Proper grounding and shielding; twisted-pair cabling; filtering; stable power.
• B. Increasing sensor length.
• C. Using higher resolution ADC only.
• D. Removing calibration.

Answer: (C)

Ground-loop noise arises when there are differences in ground potential and a physical loop that picks up interference. The most effective mitigation combines solid grounding and shielding, using twisted-pair cabling to minimize loop area, applying filtering to remove unwanted frequencies, and keeping the power supply stable and clean to prevent ground ripple. Together, these practices minimize how noise couples into the instrumentation loop and keep the signal path robust.

Merely increasing the ADC’s resolution doesn’t fix the underlying noise problem; it may just reveal more detail of the existing noise without removing it. Increasing sensor length tends to enlarge the loop area and make the system more susceptible to interference, not less. Removing calibration doesn’t address noise either.