C4 LT4 Flashcards
What is an analogue-to-digital converter?
Converts analogue voltage into a digital signal
What are some causes of transient voltages?
Lightning strikes, unfiltered equipment, power being switched on and off
Why is it important to use proper test leads when using test equipment?
Ensure safety
What is the recommended procedure for connecting the leads of a DMM to a circuit or component?
Black lead to negative, red lead to positive. Black lead connected first.
Where do you plug the black test lead when measuring DC voltage with a DMM?
Jack labelled ‘COM’
What should be used if the current is higher than what the meter is rated for?
AC clamp-on ammeter
When should you use a DC clamp-on ammeter?
current higher than meter rating
Why should you never connect a DMM set for ohms to an energized circuit?
Damage the meter
What type of display do digital meters have?
Numerical digits
What do the categories in a DMM classify?
Application and equipment usage for testing voltages up to 1000 volts
Where is the category rating usually stamped on?
Test probe
What does protective clothing made of durable flame-resistant material provide protection from?
Hot and sharp objects
Where do you plug the red test lead when measuring DC voltage with a DMM?
Jack labelled ‘V’
What should you do before testing a component with a DMM set to resistance?
Remove or isolate
What are panel types of meters used for?
Displaying electrical measurements
What does a category-rated meter provide protection from?
Overcurrent faults
What should you do if a test lead is damaged?
Replace with new one with same category rating
What is required to protect from falling objects, impact, and electrical shock?
Hard hat or protective helmet
Where is the bench type meter commonly used?
In lab areas and on workbenches
What is the hand-held type of meters used for?
Troubleshooting and field measurements
What precaution should be taken when working with circuits?
Assume energized until confirmed de-energized
What organization sets the standards for electrical measurement category ratings for test tools?
IEC (International Electrotechnical Commission)
What is a transient voltage?
Temporary voltage spike in an electrical circuit
What should be the relationship between the category rating of test leads and the tester?
Equal or exceeds
What should be checked for on test leads?
Wear and abuse
What protective equipment should be worn when working with circuits?
Appropriate gear for area
What is the advantage of digital meters over analogue meters?
Faster and easier to read
Where is Category I equipment used?
Protected electronic equipment not directly connected to mains
What may also be stamped on a test lead?
Amperage rating
Should correct polarity be ensured when connecting test leads to an AC voltage waveform?
No
Where are analogue-to-digital converters used?
Digital meters
Where is Category II equipment used?
Single-phase receptacle-connected loads like appliances and portable tools
Should correct polarity be ensured when connecting test leads to a DC voltage?
Yes
What should be done if a negative sign is displayed in the DMM’s display window during measurements?
Reverse the meter leads.
What should you do first when measuring DC voltage with a DMM?
Set function switch to DC volts
What should you do before plugging in the test leads when measuring AC amps?
Set to highest current range
Why is it important not to change the function switch position while the circuit is energized?
To avoid damage or injury
How should the ammeter be connected in the circuit for measurement?
In series
To avoid damaging the meter, what should you do if you are done with current measurements?
Turn function selector switch to OFF position
What are the steps to connect a DC clamp-on ammeter?
turn off power, open circuit, connect leads
Where should you plug the black lead when using a DMM for resistance?
Common jack
Where should you plug the red lead when using a DMM for resistance?
Resistance jack (N)
