NI sbRIO-961x/9612XT/963x/9632XT/964x/9642XT 42 ni.com
Accuracy details
Absolute accuracy formulas
AbsoluteAccuracy = Reading · GainError + Range · OffsetError +
NoiseUncertainty
GainError = ResidualGainError + GainTempco ·
TempChangeFromLastInternalCal + ReferenceTempco ·
TempChangeFromLastExternalCal
OffsetError = ResidualOffsetError + OffsetTempco ·
TempChangeFromLastInternalCal + INL_Error
NoiseUncertainty = (RandomNoise · 3) / for a coverage factor of 3σ
and averaging 100 points.
Absolute accuracy at full scale on the analog input channels is determined
using the following assumptions:
TempChangeFromLastExternalCal = 45 °C
TempChangeFromLastInternalCal = 5°C
NumberOfReadings = 100
CoverageFactor = 3 σ
For example, on the 10 V range, the absolute accuracy at full scale is as
follows:
GainError = 94 ppm + 23 ppm · 5 + 5 ppm · 45
GainError = 434 ppm
OffsetError = 20 ppm + 49 ppm · 5 + 76 ppm
OffsetError = 341 ppm
Nominal
Range (V)
Residual
Gain
Error
(ppm of
Reading)
Gain
Tempco
(ppm/°C)
Reference
Tempco
Residual
Offset Error
(ppm of
Range)
Offset
Tempco
(ppm of
Range/°C)
INL Error
(ppm of
Range)
±10 94 23 5 20 49 76
±5 104 23 5 20 50 76
±1 114 23 5 25 62 76
±0.2 154 23 5 40 118 76