43
Model UT107: OPERATING MANUAL
5. RPMx10 Testing
(see figure 19)
Set the rotary switch to
RPMx10
and select the
number of cylinders in the automobile to be tested.
As prompted at the LCD connect terminal, insert the
red test lead into the terminal and the black one
into the
COM
terminal.
Connect the black test lead probe to the ground (i.e.
ground strap connection) of the automobile and the
red one to: the appropriate testing test terminal of
the computer of the automobile if the automobile is
in a DIS type (Refer to the servicing handbooks of
various kinds of automotive manuals for the detailed
position); or the negative pole of the ignition coil if
the automobile is equipped with a distributor board
(Refer to the servicing handbooks of various kinds
of automotive manuals for the detailed position).
The normal starting rotation speed of an engine is
about 50 RPM to 275 RPM. Refer the detailed position
to the servicing handbooks of various kinds of
automotive manuals because this value relates to
the then temperature, engine size, battery size, etc..
(1)
(2)
(3)
(4)
(figure 19)
Warning
The displayed value of the meter becomes the actual
tach reading only after it is multiplied by 10.
Red
Black
Ignition Coil
Ground
