Multimeters: electrical measurements

Multimeters can measure multiple elec properties.
You can measure resistance, voltage, current, or continuity.

• Resistance:
  

1. turn off the device and disconnect it from its power source. (Leaving it connected could damage the meter). Also might need to disc from its circuite.
   
2. Set the MM to read resistance. Might need to set the scale also.
3. Touch the black and red probes to either side of the circuit and read the display.

• Voltage:

1. Set MM to read either AC or DC. Also the range if needed.
2. Touch the black probe to the ground and the red probe to where you want to measure.
3. If you have an analog meter and the needle tries to swing backwards, you have the red probe on the ground.
   
4. Device must be turned on and connected to its power source.
   

• Current

1. You must break the circuit and insert the MM into the break.
   
2. The current in the circuit will then flow through the meter (which is designed not to disrupt the flow noticeably).
   
3. Clamp ammeters are used to clamp around a wire to measure the current flow.
   

• Continuity

1. Fuses intact or wires whole?
   
2. Which pins on one end of a cable are connected to which pins on the other end?
   
3. Set MM to display resistance (ohms) and look for circuits with zero resistance.
   

Most of the time, you might need to measure voltage, resistance and continuity (hardly ever current).

• Check the output voltage of a power supply at various leads.
  
• Check to see if approp wall voltage is available.
  
• Measure resistance most often when determining is a cable is whole.