Model 2651A High Power System SourceMeter® Instrument Reference Manual
Appendix B: Calibration
2651A-901-01 Rev. A / March 2011
B-3
Description Manufacturer/model
Accuracy
Digital multimeter (continued)
DC current
50 nA: ±2700 ppm
90 nA: ±1500 ppm
500 nA: ±1200 ppm
900 nA: ±750 ppm
5
μ
A: ±600 ppm
9
μ
A: ±420 ppm
50
μ
A: ±170 ppm
90
μ
A: ±110 ppm
0.5 mA: ±150 ppm
0.9 mA: ±100 ppm
5 mA: ±170 ppm
9 mA: ±110 ppm
50 mA: ±150 ppm
90 mA: ±100 ppm
500 mA: ±1600 ppm
900 mA: ±950 ppm
2.5 A: ±420 ppm
4.5 A: ±290 ppm
5 A: ±600 ppm
9 A: ±460 ppm
10 A: ±400 ppm
18 A: ±310 ppm
DC current
Pulse only*
20 A: ±750 ppm
45 A: ±620 ppm
Precision resistor: 0.1
Ω
, 250 W,
0.1%
Isotek
RUG-Z-R100-0.1-TK1
Resistance**
0.1
Ω
: ±75 ppm
* To verify this pulse current, DMM must be able to complete its measurement of the shunt voltage within 500
μ
s of
receiving a trigger signal
** Resistor used to test 1 A, 5 A, 10 A, and 20 A ranges (DC level), and 50 A range (pulse). Before use, characterize the
resistor to the uncertainty shown.
Verification limits
The verification limits stated in this section have been calculated using only the Model 2651A one-
year accuracy specifications, and they do not include test equipment uncertainty. If a particular
measurement falls outside the allowable range, recalculate new limits based both on the Model
2651A specifications and corresponding test equipment specifications.
Source limits calculations
As an example of how to calculate source verification limits, assume you are testing the Model 2651A
10 V DC output range using a 9 V output value. Using the one-year accuracy specification for the
10 V range DC output of ± (0.02% of 5 mV offset), the calculated output limits are:
Output limits = 9.0 V ± [(9.0 V
×
0.02%) + 5 mV]
Output limits = 9.0 V ± (0.0018 + 0.005)
Output limits = 9.0 V ± 0.0068 V
Output limits = 8.9932 V to 9.0068 V
Source limits for current are calculated in the same way but using the Model 2651A instrument's
current source specifications.
