Urrea UD88 User's Manual And Warranty Information page 63

In this case, use the Hz of RPM IG mode to get the
correct readings.
To measure frequency (Hz):
• Select the Hi-Sen Hz setting with the rotary switch.
Insert:
- Black lead in COM jack.
- Red lead in VΩRPM CAP jack.
Connect:
- The Black test probe to GROUND side.
- The Red test probe to the "SIGNAL OUT" wire of the
object to be tested.
NOTE: The display will show 00.00Hz for frequencies below
0.5Hz.
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 the
trigger level.
NOTES:
1. Position the pickup as far away from the distributor and
the exhaust manifold as possible.
2. Position the pick up within six inches of the spark plug
or move it to another plug wire if no reading or an erratic
reading is received.
RPM Measurements Using the Inductive Pickup
(RPM IP mode)
RPM refers to Revolutions Per Minute. Using the
inductive pickup, which comes with the Meter, RPM
can be measured by clamping it around any spark plug
wire of a two or 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 TURNED OFF BEFORE CONNECTING OR REMOVING THE
INDUCTIVE PICKUP.
To measure RPM:
• Select the RPM IP range with the rotary switch.
• Press the RANGE button to select either 2 or 4 stroke
engine.
Insert:
• The DUAL BANANA CONNECTOR into the input jacks
as shown. Ensure that the plug with the GROUND
TAB goes into the COM jack.
RPM Measurements Using the Test Leads
(RPM IG mode)
This exercise shows how to measure RPM using
the test leads from the primary side of the regular
conventional distributor type ignition coils.
In order to measure RPM, you need to determine
whether you are looking at a two stroke or a four
stroke engine and how many cylinders are in the
engine.
When the RPM IG setting is first selected, the Meter
defaults to four strokes and four cylinders so that RPM
IG, STR, CYL, AT, TRIG and – appear on the display.
If you want to select other number of cylinder, press
E N G L I S H
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