πŸ”¬
EIM Academy
  • πŸ‘Welcome to EIM Learning Center
  • Electronics Engineering
    • Electronics Enegineering
    • πŸ‘01-Basic Electricity
      • Before Your First Circuit
      • Measure electricity
      • Electromagnetic Induction
    • πŸ‘02-Electrical Circuits
      • Ohm's Law
      • Series and Parallel Circuits
      • Voltage and Current Divider
      • Watt’s Law
      • Kirchhoff's laws
    • πŸ‘03-Analog Circuits and Semiconductors
    • πŸ‘04-Digital Circuits and FPGA
      • Chapter 3 Code
      • Chapter 4 Code
      • Chapter 5 Code
      • Chapter 6 Code
      • Design for Simulations
    • ✍️05-Engineering Signals and Analog Filters
  • Skill Development
    • πŸ‘01-Breadboarding Skills
      • Tools & Accessories
      • Breadboard Projects
    • πŸ‘‰02-Electronics Soldering
      • Practice Projects
    • ✍️03-Perfboard Prototyping
  • Project-based Learning
    • πŸ‘Green Electrical Energy
    • πŸ‘Smart Traffic Light
      • Board Design
      • STEPico & Micropython
      • STEPFPGA & Verilog
      • Demos
    • ✍️Electronic Pinao with FPGA
    • ✍️Semiconductor Cooler
      • What You'll Learn
      • Technical Docs
      • Project Demo
    • πŸ‘Smart Greenhouse
      • Irrigation System
      • Lighting System
      • Temperature Control System
      • Humidity Control System
    • πŸ‘AI with Hardware
      • Finger Detection
      • LCD control by Hand Gesture
      • Robotic Hand
      • Facial Recognition Security System
      • Common Questions
      • Video Tutorial
  • ✍️Bio-medical Applications
    • Blood Oximeter
    • Electrocardiogram
    • Electromyography
  • Educational Development
    • πŸ‘‰Educational Development
    • Educators' Repository
    • Basic Electronics Lesson Plan
      • Electronics Components
      • Ohm's Law
      • Series & Parallel Circuit
      • Watt's Law
      • Kirchhoff's Law
Powered by GitBook
On this page
  • Measure Voltage
  • Preparing Device
  • Be Aware to Polarity
  • Testing & Reading

Was this helpful?

  1. Electronics Engineering
  2. 01-Basic Electricity

Measure electricity

Visualizing electricity with instruments

PreviousBefore Your First CircuitNextElectromagnetic Induction

Last updated 1 year ago

Was this helpful?

Measure Voltage

The learning kit includes an voltmeter and an ammeter. Since they operate in very different manners, make sure you use the correct one for the measurements. We start with voltage measurement. To measure voltage, we are going to use the blue voltmeter.

Preparing Device

Before connecting a voltmeter to a circuit, the voltmeter should be set to its maximum range first. For the voltmeter in this experiment, there is a toggle switch at the bottom of the panel. This voltmeter only has two ranges, 0 - 3 V and 0 - 15 V. Switch it to the side with the printed number β€œ15”.

Be Aware to Polarity

It is notable that the voltmeter also has a β€œ+” and β€œ-” symbols. These symbols indicate the default polarity of the voltmeter while interpreting the measured voltages. This means when connecting a voltmeter to a circuit, you are recommended to connect the meter’s positive polarity to the higher voltage terminal of the circuit being measured whereas the negative polarity connects to the lower voltage terminal.

Testing & Reading

Recall our discussion on voltage polarities earlier. Reversing the polarity of measurement may yield a negative reading on the meter, indicating a voltage drop with the opposite sign to the actual measurement. However, some analog voltmeters lack a scale to the left of 0 and are not intended to read negative voltages. In such cases, reversing the polarity of the measured voltage will not cause the needle to move into a negative range. Instead, the needle will either remain at 0 or may deflect slightly due to internal structure, but it does not provide a meaningful measurement.

When using a voltmeter for testing, it is always recommended to start with the highest range setting (15V for our voltmeter) if you are unsure about the possible voltage range being measured. This is to prevent over-ranging, which can potentially damage the meter. Once you have confirmed that the voltage is within a lower range, you can then adjust the voltmeter to that range for a more precise reading.

After connecting the two test probes in parallel to the two terminals of the device to be measured, the readout on the voltmeter is the voltage difference (or voltage drop) across the two terminals you measured.

πŸ‘
The voltmeter in the learning kit
Switching the range to 15V
Connecting the voltmeter
Negative reading (left)