| Intermediate Technology Education | Energy and Power Technology | Pre-Design | Topic 3 | Optional Activity 1 |

Using a Multimeter

Measure Electrical Resistance

Example

The image below shows a resistor being measured.  Note where the probes connect to the meter.   You may also notice that the probes have adaptors with small spring loaded hooks, which are used to hold the resistor.  The selector has been set to 2 kΩ, and the reading is .327 — or .327 kΩ.  Can you get rid of the decimal point?  Of course you can.

Measuring Resistance

Figure. Measuring Resistance

Keep in mind that kilo means a multiplier of 1000, so just multiple .327 by 1000

.327 kΩ

.327 × 1000 Ω

327 Ω

The resistor has a value of 327 Ω.

Measure Resistance

Using the example above as a guide, measure the value of several resistors. 

Make an appropriate entry in your course portfolio.

Measure Electrical Voltage

Example

Voltage readings are taken across the device that is consuming the electricity.  The meter is connected in parallel with the device.  In the image below, a light bulb is powered by battery which consists of two 1.5 volt D cells.  The meter is set at 20 V DC, and has a reading of 2.79 volts.  This means that the voltage drop across the light is 2.79 Volts.

Measuring Electrical Voltage

Figure. Measuring Voltage

The next image shows a schematic of the voltmeter setup.

Measuring Voltage Schematic

Figure. Measuring Voltage Drop across a Load (bulb) Schematic

Measure Voltage

Using the example above as a guide, measure the voltage across a load in the following circuits

  • A battery powered motor or light/LED
  • A solar cell powered motor or light/LED

 

Make a suitable entry in your course portfolio

 

Measure Electrical Current

Example

Current readings are taken with the meter in series with the device that is consuming electricity.  In the image below, the load is a light bulb and the voltage source is a battery which consists of two 1.5 volt D cells. The meter has been set up with the probe in the 10 A socket.  The current reading is .53 amps.  We can say that the light bulb consumes .53 amps of electricty.

Measuring Electrical Current

Figure. Measuring Electrical Current

The next image shows a schematic of the ammeter setup.

Current Schematic

Figure. Measuring Electrical Current

Measure Current

Using the example above as a guide, measure the current flow in the following circuits

  • A battery powered motor or light/LED
  • A solar cell powered motor or light/LED

Make a suitable entry in your course portfolio

When you are done notify your instructor.