7-4
Relative and Math
Math operations
Math functions
The SourceMeter has built-in math functions to calculate the following:
•
Power
•
Offset Compensated
Ω
•
Varistor Alpha
•
Voltage Coefficient
•
Percent Deviation
The Power and Percent Deviation math functions use a single voltage and/or current mea-
surement to perform the calculation. The Offset-Compensated
Ω
, Varistor Alpha, and Voltage
Coefficient math functions require 2-point measurements to perform a calculation.
Power
This math function calculates power using the measured voltage and measured current val-
ues as follows:
Power = V
×
I
where: V = measured voltage
I = measured current
Offset-compensated
Ω
The presence of thermal EMFs (V
EMF
) can adversely affect low-resistance measurement
accuracy. To overcome these unwanted OFFset voltages use the Offset Compensated
Ω
mea-
surement method. In general, this method measures resistance (V/I) at a specific I-Source level
and then subtracts a resistance measurement made with the I-Source set to a different level
(typically zero).
NOTE
Offset-compensated
Ω
is also available from the CONFIG OHMS menu structure.
Using Offset-Compensated
Ω
from this menu automatically selects zero as one of the
source values. For details, see Section 4, “Offset-compensated ohms.”
This two-point measurement method is mathematically expressed as:
Offset-Compensated
Ω
=
∆
V /
∆
I where
∆
V = V2 – V1 and
∆
I = I2 – I1.
•
V1 is the voltage measurement with the I-Source set to a specific level.
•
V2 is the voltage measurement with the I-Source set to a different level (typically zero).
•
I1 is the current measurement with the I-Source set to a specific level.
•
I2 is the current measurement with the I-Source set to a different level (typically zero).
You will be prompted to enter the two I-Source values. See
Front panel math operations
.
Summary of Contents for 6430
Page 26: ......
Page 32: ......
Page 78: ...2 14 Connections ...
Page 98: ...3 20 Basic Source Measure Operation ...
Page 138: ...5 30 Source Measure Concepts ...
Page 156: ...6 18 Range Digits Speed and Filters ...
Page 168: ...7 12 Relative and Math ...
Page 176: ...8 8 Data Store ...
Page 202: ...9 26 Sweep Operation ...
Page 248: ...11 22 Limit Testing ...
Page 310: ...16 6 SCPI Signal Oriented Measurement Commands ...
Page 418: ...17 108 SCPI Command Reference ...
Page 450: ...18 32 Performance Verification ...
Page 477: ...A Specifications ...
Page 489: ...B StatusandErrorMessages ...
Page 498: ...B 10 Status and Error Messages ...
Page 499: ...C DataFlow ...
Page 503: ...D IEEE 488BusOverview ...
Page 518: ...D 16 IEEE 488 Bus Overview ...
Page 519: ...E IEEE 488andSCPI ConformanceInformation ...
Page 523: ...F MeasurementConsiderations ...
Page 539: ...G GPIB488 1Protocol ...
Page 557: ......