21 22
Ω
Ω
Meter Functions-Duty Cycle (%)
Select the
“%
Duty”
Cycle
function with the rotary switch.
Insert:
Black lead in
COM
terminal.
Red lead in
V-
Ω
-RPM
terminal.
Connect the Black test probe to
ground.
Connect the Red test probe to
the signal wire circuit.
The illustration for a mixture
control solenoid is shown with the
metering rod in the closed
position. The meter will display
the percentage of time the
plunger is in the closed position.
(low duty cycle) during one duty
cycle.
Meter Functions- ms-PULSE (Pulse Width) &
ms- PERIOD (Period)
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 injectors 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.
Measuring Pulse Width on Port Fuel injectors is described on the
following page.
(continued on next page)
