E2 Digital Multi Meters

True or false : the bar graph has a polarity indicator on the left side ?

True

True or false; The bar graph acts like a needle on the analogue meter ?

True

List two advantages of a clamp on style ammeter over a DMM ?

Able to measure currents in excess of 10a, Circuit does not have to be de energized to take current measurement.

What is the wind on the DMM called where the reading appears ?

display

When using the diode test function to a silicon diode, if the diode is good a DMM will display the ________?

forward bias voltage drop

What are these false readings called ?

ghost or stray voltages

How can you extend the range of a digital clip on ammeter

more loops

List three types of electrical equipment that could have their insulation resistance tested ?

motors, transformers, cables, insulators

How is a voltmeter connected in a circuit ?

parallel

What are the two main types of displays for digital multi meters ?

LCD and LED

what is the minimum reading expected when meggering a motor conductor ?

1 megohm

What is the impedance value of most digital multi meters ?

10 Mega ohms

What is the typical input impedance of a digital multimeter ?

10 megaohm

Which DMM setting would used to measure the voltage output of a Alternator ?

AC Volts

What CSA standard covers workplace electrical safety ?

CSA Standard Z462 - 15

Identify one cause of false readings on a DMM on a de energized circuit.

Capacitive couplings

What category of dmm is required for testing where fault currents are very high?

Cat IV

What source voltage of the circuit is 120 Volts AC, and the resistance of the circuit 10 ohms. What type of ammeter would you use to measure the current in the circuit ?

Clamp on DMM max 10a

Which meter is used to take current measurement without opening the circuit ?

Clamp on ammeter

Which DMM setting would be used to measure the voltage output of a Rectifier ?

DC Volts

Which meters are more accurate: analogue or digital ?

Digital

Which meters are more commonly used in the electrical trade: Analogue or digital ?

Digital

What is the abbreviation DMM short for ?

Digital Multi Meter

What should always be done with a conductor before and after megger testing the conductor ?

Discharge each conductor to system ground

Which type of digital meter is best suited for electricians ?

Handheld DMM

When measuring voltage across a component, will meter loading cause the meter reading to be higher or lower than the voltage across the component without the meter in the circuit ?

Lower

List three causes of insulation deterioration

Mechanical damage, fault currents, excessive heat

If you are using the manual range and you see OL displayed, what does this mean ?

Overload

Which measurement function of a DMM requires an internal battery to provide current flow through the circuit ?

Resistance or ohms

List two applications where meggers are used

Routine maintenance programs, to verify conductors in raceways

How does a digital meter display its measurements ?

Segment display

How is a ammeter connected in a circuit ?

Series

What must be done before using DMM on a circuit ?

Test on a known circuit

What is the principle of operation of an AC/DC digital clamp on ammeter ?

The hall effect generator

The category rating of test leads should exceed the category rating of the DMM, true or false ?

True

Which of the two meter types, true rms or average responding would be used by an electrician testing an electronic ballast in a fluorescent lighting fixture ?

True RMS

Which meter is very popular ?

True RMS DMM

Which DMM function is used to measure current flow in an electrical circuit ?

ammeter

List three commonly available styles of digital meters.

cabinet, bench, handheld

Which meter function would be selected to provide quick and easy testing of whether a fuse is open or has a complete path through it ?

continuity

Which DMM function is used to measure resistance ?

ohmmeter

what must be done to get an accurate reading if OL appears on the display when the DMM is on manual range ?

switch to a higher range

Which feature of DMM would best be used to detect a rapidly changing signal such as contact bounce on a microswitch ?

the bar graph reading

Which feature of a DMM would best be used to detect a rapidly changing signal such as contact bounce on a microswitch ?

the bar graph reading