Unit 7. General Purpose Test Equipment Instruments Flashcards
- Fluke 8025A Multimeter
1. Which control do you use to select the meter’s different measurement functions?
The rotary switch.
List the four types of information presented in the multimeter’s display section.
(1) Digital display.
(2) Visual annunciators.
(3) Analog bar graph.
(4) Range indicator.
Which information in the display section shows the absolute value of the input?
Analog bar graph.
Describe the function of the range push button.
The range push button lets you manually select the measurement range.
What is the purpose of the touch-hold push button?
The touch-hold push button locks the measurement into the display for viewing and automatically updates
the display when you take a new measurement.
List the multimeter’s four input jacks.
(1) Amperes
(2) Milliamps/microamps.
(3) V olts/ohms/diode.
(4) Common.
When does the 8025A perform a power-up self-test?
- When you move the rotary switch to any position from the OFF position
- Using the Fluke 8025A Multimeter
1. What two ranges of DC voltages can you measure using the 8025A multimeter?
- What is the maximum amount of continuous AC current you can measure with the multimeter?
10 amps.
- When using the Fluke 8025A, how do you know you’re in the resistance measurement function?
The ohms annunciator is showing in the display.
- How do you determine if you’re testing a “good” diode with the 8025A?
Placing the leads across a “good” diode produces “OL” in the display while reversing the leads produces a continuous audible tone.
- Oscilloscope basics
1. What type of display does the oscilloscope present?
Amplitude vs time.
- On which axis of an oscilloscope is voltage, time, and depth information presented?
Voltage = Y axis, time = X axis, and depth = Z axis.
- What is the purpose of the delay line at the input of the vertical amplifier?
It allows the sweep generator circuitry time to start a sweep before the signal reaches the cathode ray tube vertical deflection plates. This enables you to view the leading edge of the signal waveform.
- What position of the input coupling switch is used to view digital-type or square wave signals?
DC coupling.
- Basic oscilloscope probe considerations
1. What is the basic purpose of the oscilloscope probe?
To provide isolation for scope inputs and prevent circuit loading.
- List four types of probes.
(1) Passive.
(2) Passive divider.
(3) Active (field effect transistor).
Amperes.
(4) Current probes.
- What is the typical input impedance of most oscilloscopes?
One megaohm shunted by 20 pF of capacitance.
- When making an amplitude measurement and the source impedance is unknown, greatest accuracy is achieved when the probe’s Zin is what?
Highest (maximum).
- Why do we test ground?
1. Why do we test ground?
To verify the ground-resistance specification that the ground rod or grid must meet.
- What test equipment is used to identify a poor ground?
Earth ground tester.
- Basics of earth ground testing
1. What is another name for the fall of potential test method?
The three-point method.
- What is each point of contact called in the fall of potential testing method?
(1) The test ground.
(2) V oltage probe.
(3) Current probe.
- At what distance represents the closest value to the theoretical true resistance measurement?
61.8 percent of the total distance.