Uploaded September 2026 | Updated September 2026, 1 week ago
What actually happens inside a digital multimeter when you measure DC voltage? In this video, I go far beyond simply showing you where to put the probes. We follow the measurement from the 9V battery, through the test leads and into the multimeter itself, to discover how that 9.00V reading actually appears on the screen.
You’ll see how to correctly set up a digital multimeter for DC voltage testing, where to connect the COM and VΩ leads, and how to test a 9V battery practically. Then we take the journey inside the meter.
Using detailed visual demonstrations, I explain the electron/current path through the meter, why a voltmeter has an extremely high input resistance (often around 10 MΩ), how this prevents the meter from effectively short-circuiting the battery, and how the meter senses the potential difference between its two probes.
We then follow the signal into the multimeter’s internal measuring electronics and look at how the analogue-to-digital converter (ADC) turns an analogue electrical measurement into the digital voltage value you finally see on the LCD.
We’ll also look at the role of the multimeter’s internal protection components and, importantly, what the battery itself is doing chemically to create the electrical potential difference in the first place.
If you’ve ever used a multimeter and wondered “But how does it actually know that’s 9 volts?”, this video is designed to answer that question visually, from beginning to end.
🔧 In this video: DC voltage testing • 9V battery testing • multimeter probe connections • COM and VΩ inputs • electron/current flow • high input resistance • voltage sensing • ADC operation • digital display • multimeter protection circuitry • battery chemistry
Subscribe to The Repair Specialist (TRS) for practical repair, diagnostics, engines, electrical testing and detailed explanations of how things actually work.
⚠️ Safety: This video is for educational purposes. Electrical testing can be hazardous. Always follow the multimeter manufacturer’s instructions, use appropriately rated equipment and never work on hazardous voltages unless you are competent and suitably trained.
#Multimeter #DigitalMultimeter #Voltage #DCVoltage #Electronics #ElectricalTesting #HowItWorks #TheRepairSpecialist #TRS
What actually happens inside a digital multimeter when you measure DC voltage? In this video, I go far beyond simply showing you where to put the probes. We follow the measurement from the 9V battery, through the test leads and into the multimeter itself, to discover how that 9.00V reading actually appears on the screen.
You’ll see how to correctly set up a digital multimeter for DC voltage testing, where to connect the COM and VΩ leads, and how to test a 9V battery practically. Then we take the journey inside the meter.
Using detailed visual demonstrations, I explain the electron/current path through the meter, why a voltmeter has an extremely high input resistance (often around 10 MΩ), how this prevents the meter from effectively short-circuiting the battery, and how the meter senses the potential difference between its two probes.
We then follow the signal into the multimeter’s internal measuring electronics and look at how the analogue-to-digital converter (ADC) turns an analogue electrical measurement into the digital voltage value you finally see on the LCD.
We’ll also look at the role of the multimeter’s internal protection components and, importantly, what the battery itself is doing chemically to create the electrical potential difference in the first place.
If you’ve ever used a multimeter and wondered “But how does it actually know that’s 9 volts?”, this video is designed to answer that question visually, from beginning to end.
🔧 In this video: DC voltage testing • 9V battery testing • multimeter probe connections • COM and VΩ inputs • electron/current flow • high input resistance • voltage sensing • ADC operation • digital display • multimeter protection circuitry • battery chemistry
Subscribe to The Repair Specialist (TRS) for practical repair, diagnostics, engines, electrical testing and detailed explanations of how things actually work.
⚠️ Safety: This video is for educational purposes. Electrical testing can be hazardous. Always follow the multimeter manufacturer’s instructions, use appropriately rated equipment and never work on hazardous voltages unless you are competent and suitably trained.
#Multimeter #DigitalMultimeter #Voltage #DCVoltage #Electronics #ElectricalTesting #HowItWorks #TheRepairSpecialist #TRS
