Actron Digital Multimeter CP7676 - Manual (Page 6)

4
CYL 5
CYL
6
CYL
8
CYL
2K 200
200
750
20
2
20M
2M
200K
20K
DC V
AC V
OHMS
® CP7676
RPM
X10
750V AC
200V DC
COM V
DWELL
4
CYL
5
CYL
6
CYL
8
CYL
OFF
4
CYL 5
CYL
6
CYL
8
CYL
2K 200
200
750
20
2
20M
2M
200K
20K
DC V
AC V
OHMS
® CP7676
RPM
X10
750V AC
200V DC
COM V
DWELL
4
CYL
5
CYL
6
CYL
8
CYL
OFF
4
CYL 5
CYL
6
CYL
8
CYL
2K 200
200
750
20
2
20M
2M
200K
20K
DC V
AC V
OHMS
® CP7676
RPM
X10
750V AC
200V DC
COM V
DWELL
4
CYL
5
CYL
6
CYL
8
CYL
OFF
Setting the Range
Two of the most commonly asked questions
about digital multimeters are What does
Range mean? and How do I know what
Range the multimeter should be set to?
What Does Range mean?
Range refers to the largest value the
multimeter can measure with the rotary
switch in that position. If the multimeter is
set to the 20V DC range, then the highest
voltage the multimeter can measure is 20V
in that range.
EXAMPLE: Measuring Vehicle Battery
Voltage (See Fig. 1)
6
Now assume we set the multimeter to the 2V
range. (See Fig. 2)
The multimeter display now shows a “1” and
nothing else. This means the multimeter is
being overranged or in other words the
value being measured is larger than the
current range. The range should be
increased until a value is shown on the
display. If you are in the highest range and
the multimeter is still showing that it is
overranging, then the value being measured
is too large for the multimeter to measure.
How do I know what Range the multimeter
should be set to?
The multimeter should be set in the lowest
possible range without overranging.
EXAMPLE: Measuring an unknown
resistance
Let’s assume the multimeter is connected to
an engine coolant sensor with unknown
resistance. (See Fig. 3)
Start by setting the multimeter to the largest
OHM range. The display reads 0.0 Ω or a
short circuit.
Let’s assume the multimeter is connected to
the battery and set to the 20V range.
The display reads 12.56. This means there is
12.56V across the battery terminals.
This sensor can’t be shorted so reduce the
range setting until you get a value of
resistance.
At the 200K Ω range the multimeter
measured a value of 4.0. This means there
is 4K Ω of resistance across the engine
coolant sensor terminals. (See Fig. 4)
If we change the multimeter to the 20K Ω
range (See Fig. 5) the display shows a value
of 3.87K Ω . The actual value of resistance is
Fig. 1
Black Red
Black Red
Fig. 2
Red
Black
Fig. 3