©
National Instruments Corporation
13
NI 9205/9206 Calibration Procedure
Device Test Limits
Table 4 lists the specifications that the NI 9205/9206 meets if it has been
two years between calibrations.
Using the Table
The following definitions describe how to use the information from
Table 4.
Range
Range
refers to the minimum or maximum voltage range of an input signal.
AbsoluteAccuracy = Reading · (GainError) + Range · (OffsetError) + NoiseUncertainty
GainError = ResidualAIGai GainTempco · (TempChangeFromLastInternalCal) +
ReferenceTempco · (TempChangeFromLastExternalCal)
OffsetError = ResidualAIOffse OffsetTempco · (TempChangeFromLastInternalCal) +
INL_Error
Noise Uncertainty = RandomNoise · 3 /
for a coverage factor of 3
Σ
and averaging
10000 points
ResidualAIGainError = ErrorRelativetoExternalRef
ppm
+ ReferenceDriftOverTime
ppm_per_year
·
GainTempco = AnalogCircuitryGainTempco
ReferenceTempco = ReferenceDriftOverTime
ppm
ResidualOffsetError = OffsetErrorDueToCalibration
ppm
OffsetTempco = PreGainOffsetTempco
μ
V
/ Range
V
+ PostGainOffsetTempco
INL_Error = 2 · ADC_Dithered_INL
RandomNoise = RandomNoise
μ
Vrms
10000
CalibrationInterval
years