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NAME: _________________________
PERIOD:________________________
Test Equipment Introductory Lab
Using a handheld Volt-Ohm meter
Electronics Basic Standard: 470105-3 Objective 1
Robotics and Automation Standard: 210117-6 Objective 2
Common Core Math Standard: Algebra
Background Information:
The ability to use a Multimeter to test electronics is a foundation skill. These cheap and simple
testers can be used to diagnose very complicated electronic problems.
Part 1: Determining the Multimeter Setting
(1) To determine what setting the Multimeter should be set to, you have to know what type of
electrical measurement you will be taking.
Resistance : Set the Multimeter to the “ohm” (Ω) setting.
AC Voltage : Place the meter into the AC voltage setting. This setting will be labeled either
“ACV” or “V” with a “~” (squiggly line) over or next to it.
DC Voltage : Place the meter into the DC voltage setting. This setting will be labeled either
“DCV” or “V” with a “-” (straight line) over or next to it.
Current : Place the meter into the amperage setting. This setting is labeled “A” or “ma”.
Part 2: Measuring Voltage:
(1) To measure voltage using a Multimeter you simply turn the mode setting to the type of voltage you want to measure and connect the leads. If you are using an old “pointing needle” type
of Multimeter be sure to place the meter measurement scale to the highest range and step the
range down until you get to the range where the needle is deflected from 25 percent of scale to 75
percent of scale. This protects the meter from damage. Modern digital meters do not require
this protection since they will auto range to the correct voltage setting.
(2) Place meter leads so they are polarized correctly. (Black lead to black terminal and red lead to
red terminal)
(3) Be careful to not shock yourself or place the meter tip into a circuit where they will cause a
short.
(4) For this exercise test the following voltages from the high current power supplies (blue) on
the workbenches.
Set meter initially to read DC voltages Meter setting “V-“.
A. 5 volt output (labeled): measured: ___________________
B. Variable DC output: the built-in meter shows the variable voltage. Adjust to 12 volts and then
connect the meter first between the positive (red) output and the negative (black).
Measured:__________________
Set meter to read AC voltages Meter setting “V~“.
C. AC output: Connect the meter to the AC voltage output (yellow jacks on the right side of the
power supply) and measure its output. (Set meter to read AC voltage)
Measured: __________________
Part 3: Other Measurements: Meter setting “mV”
(1) Turn the multimeter to the ” mV” Voltage setting. Tightly grasp one meter lead in each hand
and measure the voltage from your body. Record the voltage below.
AC voltage generated from your body: ___________________
(2) Now measure the AC voltage from a classmate’s body. Record the voltage below and compare the reading to your own. Was the reading greater, lesser or the same as yours?
AC voltage generated from classmate body: ________________
Classmate’s body voltage was (circle one) greater, lesser, equal to my own.
(3) Theorize why their voltage readings were either different or the same as yours?
(4) Set the meter to the resistance (Ω) setting and measure you body resistance. Tightly grasp
one meter lead in each hand and measure the resistance between the hands of your body. Record
the resistance reading below.
Body hand-to-hand resistance reading: __________________________
(5) Now measure the hand-to-hand resistance of a classmate’s body. Record the reading below
and compare the reading to your own. Was the reading greater, lesser or the same as yours?
Classmate hand-to-hand resistance reading: __________________________
Classmate’s hand-to-hand body resistance was (circle one) greater, lesser, equal to my own.
(6) Theorize why their resistance readings were either different or the same as yours?
(7) Leave the meter set to the resistance (Ω) setting and measure you body resistance between
the temples of your forehead. Lightly place one meter lead on each temple and measure the resistance of your head. Record the resistance reading below.
Body head resistance reading: __________________________
(8) Now measure the body head resistance of a classmate’s body. Record the reading below and
compare the reading to your own. Was the reading greater, lesser or the same as yours?
Classmate head resistance reading: __________________________
Classmate’s head resistance was (circle one) greater, lesser, equal to my own.
(6) Theorize why their resistance readings were either different or the same as yours?