Accuracy; Analog Input Dc Voltage Measurement Accuracy; Noise Performance; Settling Time - Measurement Computing USB-1608G User Manual

USB-1608G User's Guide

Accuracy

Analog input DC voltage measurement accuracy

Table 2. DC accuracy components and specifications. All values are (±)
Gain error
Range (% of reading)
±10 V 0.024
±5 V 0.024
±2 V 0.024
±1 V 0.024

Noise performance

For the peak-to-peak noise distribution test, a differential input channel is connected to AGND at the input
terminal block, and 32,000 samples are acquired at the maximum rate available at each setting.
Range Counts
±10 V 6
±5 V 6
±2 V 7
±1 V 9

Settling time

Settling time is defined as the accuracy that can be expected after one conversion when switching from a
channel with a DC input at one extreme of full scale to another channel with a DC input at the other extreme of
full scale. Both input channels are configured for the same input range.
Range 4 µS settling accuracy
(% FSR)
±10 V 0.0061
±5 V 0.0061
±2 V 0.0061
±1 V 0.0061

Analog input calibration

Parameter
Recommended warm-up time
Calibration method
Calibration interval
Calibration reference
Offset error INL error
(µV) (% of range)
915 0.0076
686 0.0076
336 0.0076
245 0.0076
Table 3. Noise performance specifications
LSBrms
0.91
0.91
1.06
1.36
Table 4. Input settling time specifications in µS, typical
6 µS settling accuracy
(% FSR)
0.0031
0.0031
0.0031
0.0031
Table 5. Analog input calibration specifications
Specification
15 minutes min
Self-calibration (firmware)
1 year (factory calibration)
+5 V, ±2.5 mV max. Actual measured values stored in EEPROM.
Tempco: 5 ppm/°C max
Long term stability: 15 ppm/1000 hours
17
Absolute Gain
accuracy at temperature
Full Scale coefficient
(µV) (% reading/°C)
4075 0.0014
2266 0.0014
968 0.0014
561 0.0014
±10 µS settling accuracy
(% FSR)
0.0015
0.0015
0.0015
0.0015
Specifications
Offset
temperature
coefficient
(µV/°C)
47
24
10
5