Operating instructions

250V MAX
15A MAX
FUSED
COM
DC
15A
AUTO POWER OFF CP7678
®
OFF
200
20
2
DC V
200
m
20M
200
K
20K
2K
200
8CYL
6CYL
TACH
X10
5CYL
4CYL
8CYL
6CYL
5CYL
4CYL
DWELL
DUTY
CYCLE
%
OHMS
°
20 M
15
A
250V MAX
15A MAX
FUSED
COM
DC
15A
AUTO POWER OFF CP7678
®
OFF
200
20
2
DC V
200
m
20M
200
K
20K
2K
200
8CYL
6CYL
TACH
X10
5CYL
4CYL
8CYL
6CYL
5CYL
4CYL
DWELL
DUTY
CYCLE
%
OHMS
°
2
15
A
250V MAX
15A MAX
FUSED
COM
DC
15A
AUTO POWER OFF CP7678
®
OFF
200
20
2
DC V
200
m
20M
200
K
20K
2K
200
8CYL
6CYL
TACH
X10
5CYL
4CYL
8CYL
6CYL
5CYL
4CYL
DWELL
DUTY
CYCLE
%
OHMS
°
20
15
A
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 multim-
eter can measure with the rotary switch in that
position. If the multimeter is set to the 20V DC
range, then the highest voltage the multim-
eter can measure is 20V in that range.
EXAMPLE: Measuring Vehicle Battery Volt-
age (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 show-
ing 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 resis-
tance
Let’s assume the multimeter is connected to
an engine coolant sensor with unknown resis-
tance. (See Fig. 3)
Fig. 2
Fig. 1
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.
Fig. 3
Start by setting the multimeter to the largest
OHM range. The display reads 0.0Ω or a short
circuit.
This sensor can’t be shorted so reduce the
range setting until you get a value of resis-
tance.
At the 200KΩ range the multimeter measured
a value of 4.0. This means there is 4KΩ of
resistance across the engine coolant sensor
terminals. (See Fig. 4)
Red
Black
Red
Black
Black
Red