SECTION 7 - GENERAL ELECTRICAL INFORMATION & SCHEMATICS
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Min/Max
Use of the "Min/Max" recording feature of some meters
can help when taking measurements of intermittent
conditions while alone. For example, you can read the
voltage applied to a solenoid when it is only operational
while a switch, far from the solenoid and meter, is held
down.
Polarity
Finding a negative voltage or current reading when
expecting a positive reading frequently means the leads
are reversed. Check what reading is expected, the loca-
tion of the signal and that the leads are connected to
the device under test correctly. Also check that the lead
on the "COM" port goes to the ground or negative side
of the signal and the lead on the other port goes to the
positive side of the signal.
Scale
M = Mega = 1,000,000 * (Displayed Number)
k = kilo = 1,000 * (Displayed Number)
m = milli = (Displayed Number) / 1,000
μ = micro = (Displayed Number) / 1,000,000
Example: 1.2 k
= 1200
Example: 50 mA = 0.05 A
Voltage Measurement
Resistance Measurement
Figure 7-1. Voltage Measurement (DC)
Figure 7-2. Resistance Measurement
• If meter is not auto ranging, set it to the correct range
(See multimeter’s operation manual)
• Use firm contact with meter leads
• First test meter and leads by touching leads together.
Resistance should read a short circuit (very low resis-
tance)
• Circuit power must be turned OFF before testing resis-
tance
• Disconnect component from circuit before testing
• If meter is not auto ranging, set it to the correct range
(See multimeter’s operation manual)
• Use firm contact with meter leads
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