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In the past, it was very important to test the dwell of the cut-off switch of an ignition system. The dwell
testing measures the duration which the cut-off switch remains off when the cam is turning. Today’s
automobiles are ignited electronically, and it is no longer necessary to adjust the ignition dwell.
However, the dwell testing can also be used to test a mixed-controlled solenoid.
1.
Set the rotary switch to
DWELL
. Press
RANGE
button to select the number of cylinders and
press
BLUE
button to select DWELL measurement mode.
2.
Insert the red test lead into the
DWELL
terminal and the black test lead into the
COM
terminal.
Connect the ends to be tested as illustrated.
If the cut-off switch of an ignition system is tested, 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.)
If the dwell of an arbitrary ON/OFF equipment is tested, connect the red probe to the end of the
equipment, fixed with an ON/OFF switch.
3.
Connect the black test lead probe to a ground terminal of the automobile.
4.
Read the ignition dwell of the tested automobile directly from the display
K.
Engine Tach (Rotation Speed) Testing “RPMx10
” (see figure 14)
The RPM means the rotating frequency of the main shaft of the engine per minute.
1.
Set the rotary switch to
RPM X10
. Press
RANGE
button to select the number of cylinders and
72-9280: OPERATING MANUAL