Instrumentation and Electrical (I&E) Technician Practice Test

Establishing a solid grounding and bonding network gives measurement signals a stable, low-impedance reference and a clear return path. When grounding and bonding are poor, different pieces of equipment can sit at slightly different ground potentials and stray currents can flow through unintended paths. This introduces noise into the signal path, especially as common-mode voltages that the measurement device may not fully reject. The result is noise riding on the signal, which shows up as drift over time and inaccuracy in the readings. In short, bad grounding increases electrical noise and degrades measurement accuracy.