E N G L I S H
39
measured by clamping it around any spark
plug wire of a two stroke or a four stroke
automotive engine. The inductive pickup
takes the magnetic field generated by the
current flown in the spark plug wire and
converts it to a pulse that triggers the
Meter’s RPM measurement.
Using the inductive pickup allows you
to make RPM measurements on any 2
or 4 stroke automotive engine with any
number of cylinders without physically
touching any wires.
WARNING:THE IGNITION SYSTEM
CAN GENERATE A POTENTIAL SHOCK
HAZARD. ENSURE THAT THE ENGINE IS OFF
BEFORE CONNECTING OR REMOVING THE
INDUCTIVE PICKUP.
To measure RPM:
• Select the RPM range with the rotary
switch.
• Press the DC/AC button to select either 2
or 4 stroke engine.
CONVENTIONAL
IGNITION COIL
INDUCTIVE
PICKUP
DUAL BANANA
CONNECTOR
SPARK
PLUG
GROUND
TAB
Insert:
• The DUAL BANANA CONNECTOR into the
input jacks as shown.
Ensure that the plug with the GROUND
TAB goes into the COM jack.
Connect the inductive pickup to a spark
plug wire and start the engine. If no
reading is received, unhook the pickup,
turn it over and connect again.
If the reading is too high or unstable,
adjust trigger leavel.
NOTE:
1. Position the pickup as far away from
the distributor and the exhaust manifold
as possible.
2. Position the pickup within six inches of
the spark plug or move it to another plug
wire if no reading or an erratic reading is
received.
Pulse width Measurements.
Pulse Width is the length of time an
actuator is energized. For example, fuel
injectors are activated by an electronic
pulse from the Engine Control Module
(ECM). This pulse generates a magnetic
field that pulls the injector nozzle valve
open.
The pulse ends and the injector nozzle is
closed. This Open to Close time is the Pulse
Width and is measured in milliseconds
(mS).
The most common automotive application
for measuring pulse width is on fuel
injectors. You can also measure the pulse
width of the fuel mixture control solenoid
and the idle air control motor.
This exercise shows how to measure Pulse
Width on Port Fuel Injectors.
To measure pulse width (mS):
Summary of Contents for UD226
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