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Section 2: General operation
Model 2657A High Power System SourceMeter® Instrument Reference Manual
2-34
2657A-901-01 Rev. B/December 2012
The 4-wire sensing method, as shown in the following figure (Four-wire resistance sensing),
minimizes or eliminates the effects of lead resistance by measuring the voltage across the resistor
under test with a second set of test leads. Because of the high input impedance of the voltmeter, the
current through the sense leads is negligible, and the measured voltage is essentially the same as
the voltage across the resistor under test.
Figure 9: Four-wire resistance sensing
Power measurements
Power calculations
Power readings are calculated from the measured current and voltage as follows:
Where:
P
is the calculated power
V
is the measured voltage
I
is the measured current
Basic power measurement procedure
If you need to customize the MODE key's standard watt-meter configuration, perform the following
steps to perform power measurements. The following procedure assumes that the Model 2657A is
already connected to the device under test (DUT) as explained in
(on page 2-
Содержание 2657A
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