29
Model UT107: OPERATING MANUAL
L. Engine Tach (Rotation Speed) Testing “RPMx10”
(see figure 13)
The RPM means the rotating frequency of the main shaft
of the engine per minute.
Set the rotary switch to
RPMx10
.
As prompted at the LCD connect terminal, insert the
red test lead into the terminal and the black one
into the
COM
terminal. Select an appropriate number
of cylinders. Connect the ends to be tested as illustrated.
1.
2.
( figure 13)
If a DIS ignition system without any distributor
board is used in the automobile, connect the
red test lead probe to the TACH (tachometer)
signal line (which is connected to the computer
DIS module of the automotive engine). Refer to
the automotive servicing manual for the specific
position.
If an ignition system with a distributor board is
used in the automobile, connect the red test
lead probe to the primary negative end of the
ignition coil. (Refer to the automotive servicing
manual for the specific position.)
l
l
Ignition Coil
Red
Test Lead
Black
Test Lead
Ground
