Measurement & Test#

Organized by measurement situation β€” what you need to learn about the circuit β€” rather than starting from which instrument to pick up. Each subsection starts with a measurement situation β€” safety, probing, power rails, signals, noise β€” and works through the practical questions that come up at the bench.

Subsections are ordered prerequisites-first: safety and probing technique before anything else, simple checks (continuity, components) before complex ones (signals, spectrum, protocols), and cross-cutting skills (noise, calibration) at the end.

Sections#

  • Safety & High Energy β€” Mains, high voltage, CAT ratings, and the hazard assessment that comes before every measurement.

  • Probing & Measurement Technique β€” Connecting without changing the thing being measured: loading, bandwidth, and grounding.

  • Continuity & Connections β€” The simplest checks: joints, shorts, wire mapping, and intermittent faults.

  • Component Testing β€” Go/no-go checks, actual values, tolerance, and characterizing ESR, leakage, and gain.

  • Power Rails & Supplies β€” Supply verification, regulation, ripple, current draw, sequencing, and energy storage health.

  • Signals & Waveforms β€” Following signals through the circuit: presence, shape, gain, distortion, and finding where they go wrong.

  • Time, Frequency & Spectrum β€” Signal characterization in both domains: rise times, jitter, harmonics, bandwidth, and frequency content.

  • Digital Logic & Protocols β€” Logic levels, bus health, protocol decode, clock-data alignment, and speed failures.

  • Audio & Analog Circuits β€” THD, SNR, frequency response, gain structure, and sensor interfaces where the signal is the product.

  • Noise, Interference & Grounding β€” Tracking unwanted signals: EMI, ground loops, crosstalk, coupling, and empirical fixes.

  • Calibration & Measurement Confidence β€” Trusting the readings: accuracy, artifacts, calibration status, and measurement uncertainty.

  • Test Instruments β€” Reference material for the instruments mentioned throughout: key specs, what they mean, feature tiers, and which capability level different work demands.