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read the negative (-) or positive (+) slope and display it as a percent (%) of the
total cycle.
Frequency (Hz), What is it?
Frequency is the number of times a voltage pattern repeats positive compared
to negative: ON compared to OFF, during one (1) second of time. For example;
frequency (Hz) measurements are specified for digitally controlled manifold
Absolute Pressure sensors. The frequency of the ON/OFF signals per second
are measured and displayed.
Frequency (Hz) is shown as Analog: A continuous positive to negative cycle; or
Digital: A positive to negative/ON Dig to OFF cycle.
Pulse Width. What is it?
Pulse width is the length of time an actuator is energized. Foe example; fuel
injectors are activated by an electronic pulse from the engine control module.
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).
Typical Port fuel injectors (PFI) operate with
a single ON to OFF electrical pulse.
Typical Port Throttle Body injectors (TBI) operate with an ON to HOLD to OFF
electrical pulse. This method creates a double electrical "spike". An oscilloscope
is required to measure this type of pulse.
Maintenance
Fuse and Battery Replacement
WARNING:
Avoid electrical shock; remove test leads before opening case.
Do not operate the meter or rotate the meter switch when the case is open.
1. To replace a battery or fuse, loose the three screws in the case back and
remove the case by lifting up and forward.
Replace the battery with an 9 volt alkaline battery.
2. To replace fuse, firmly grasp the printed circuit board (PC boards by the
edges and lift up and out of the case.
IMPORTANT:
To prevent contamination of the circuits, your hands must be clean and the
printed circuit board must be help by the edges.
Replace the fuse with the same type of fuse.
20A is a F20A, 500V high energy, fast acting fuse.
mA is a F500mA ,250V high energy, fast acting fuse.
Make sure the replacement fuse is centered in the fuse holder.
Carefully re-insert the PC boards into the case. Re-assemble the case, then
fasten the three screws.
Trouble Shooting
Meter will not turn ON.
