The ground clip on a conventional bench oscilloscope probe is usually connected to protective earth through the instrument.
Scope Probe Ground Clips Can Create a Short—They Are Not Floating by Default Read Post »
A plug-in power meter can help reveal appliance energy use, but a large display does not guarantee useful measurements at every load.
A Plug-In Power Meter Needs More Than a Big Display Read Post »
A shiny metal part can look surprisingly hot or cold in a thermal image without having that surface temperature.
Thermal Cameras Can Misread Shiny Metal—Emissivity Is the Catch Read Post »
A voltmeter looks across two points; a direct-reading ammeter becomes part of the current path.
Why Measuring Current Uses a Different Connection Than Voltage Read Post »
A non-contact voltage pen is a useful warning tool, but a silent pen does not prove a circuit is safe to touch.
Non-Contact Voltage Testers Can Miss or Misread a Situation Read Post »
More display digits can reveal smaller changes without making a multimeter more accurate.
Meter Counts and Digits: What the Display Specification Really Means Read Post »
An auto-ranging meter can change its decimal point and unit prefix while the measured quantity barely changes.
Auto-Ranging Can Hide a Unit Change in Plain Sight Read Post »
Clamping around an entire appliance cord can produce a near-zero current reading while the appliance is running.
A Clamp Meter Needs the Right Conductor Inside Its Jaws Read Post »
A continuity beep confirms that the meter detected a conductive path under its test conditions.
Continuity Beeps Do Not Prove a Connection Can Carry Load Read Post »
Two meters can disagree on the same AC circuit because they interpret the waveform differently.
True RMS Matters Most When the Waveform Is Not a Sine Wave Read Post »
