I-8
Delta, Pulse Delta, and Differential Conductance
Delta calculation example
Assume you wish to measure the voltage across a 1
Ω
DUT using a co10mA cur-
rent source and a voltmeter. Ideally, the measured voltage would be 10mV (V = I x R).
However, due to a 10µV thermal EMF in the test leads, the voltmeter actually reads
10.01mV (0.1% error due to EMF).
The error contributed by EMF can be eliminate by using Delta. Assume the square wave
output of the Model 622x is set to 10mA (high) and -10mA (low) and the following Model
2182/2182A measurement conversions (A/Ds) are made for the first Delta cycle.
A/D A = 10.01mV
A/D B = -9.99mV
A/D C = 10.01mV
The first Delta reading is calculated as follows:
The 10mV Delta reading effectively cancelled the 10µV EMF to provide a more accurate
measurement.
Measurement units
The fundamental measurement for Delta is voltage (Volts; V). However, the voltage read-
ing can converted into a conductance (Siemens; S), resistance (Ohms; W), or power
(Watts; W) reading by the Model 622x.
Delta
A
2
B
–
C
+
4
---------------------------
1
–
(
)
0
•
=
10.01
mV
2
9.99
mV
–
(
)
–
10.01
˙
mV
+
4
---------------------------------------------------------------------------------------
1
•
=
40
mV
4
--------------
=
10
mV
=
Summary of Contents for 2182
Page 1: ...www tek com keithley Model 2182 2182A Nanovoltmeter User s Manual 2182A 900 01 Rev B May 2017...
Page 18: ......
Page 22: ......
Page 23: ...1 Getting Started Getting Started...
Page 41: ...2 VoltageandTemperature Measurements Voltageand Temperature Measurements...
Page 68: ...2 28 Voltage and Temperature Measurements...
Page 69: ...3 Range Digits Rate andFilter Range Digits Rate andFilter...
Page 82: ...3 14 Range Digits Rate and Filter...
Page 83: ...4 Relative mX b and Percent Relative mX b andPercent...
Page 91: ...5 RatioandDelta Ratioand Delta...
Page 117: ...6 Buffer Buffer...
Page 123: ...7 Triggering Triggering...
Page 140: ...7 18 Triggering...
Page 141: ...8 Limits Limits...
Page 149: ...9 SteppingandScanning Steppingand Scanning...
Page 168: ...9 20 Stepping and Scanning...
Page 169: ...10 AnalogOutput Analog Output...
Page 175: ...11 RemoteOperation Remote Operation...
Page 205: ...12 CommonCommands Common Commands...
Page 221: ...13 SCPISignalOriented Measurement Commands SCPISignalOri entedMeasure ment Commands...
Page 225: ...14 SCPIReferenceTables SCPIRefer enceTables...
Page 239: ...15 AdditionalSCPI Commands Additional SCPICom mands...
Page 260: ...15 22 Additional SCPI Commands...
Page 261: ...A Specifications Specifications...
Page 263: ...B Statusand ErrorMessages StatusandError Messages...
Page 268: ...B 6 Status and Error Messages...
Page 269: ...C Measurement Considerations Measurement Consider ations...
Page 278: ...C 10 Measurement Considerations...
Page 279: ...D Model182Emulation Commands Model182 EmulationCom mands...
Page 284: ...D 6 Model 182 Emulation Commands...
Page 285: ...E Example Programs ExamplePro grams...
Page 293: ...F IEEE 488 BusOverview IEEE 488Bus Overview...
Page 307: ...G IEEE 488andSCPI ConformanceInformation IEEE 488and SCPIConform anceInforma tion...
Page 310: ...G 4 IEEE 488 and SCPI Conformance Information...
Page 311: ...H Measurement Queries Measurement Queries...
Page 316: ...H 6 Measurement Queries...
Page 317: ...I Delta PulseDelta and DifferentialConductance Delta Pulse Deltaand Dif ferentialCon ductance...