National Instruments NI 435 Series, User Manual, Page: 54 / 77

Appendix A Specifications
NI 435x User Manual A-6 ni.com
Accuracy Calculation Examples
The following are accuracy calculation examples:
• Measurement of 760 ° C using J-type thermocouple at 28 ° C ambient
temperature; filter setting of 10 Hz:
accuracy is 0.42 ° C
• Measurement of 760 ° C using J-type thermocouple with NI 4350 at
38 ° C and accessory (cold-junction sensor) at 23 ° C; filter setting of
10 Hz:
accuracy is 0.48 ° C as a result of
[0.42 ° C + (38 ° C – 35 ° C)
×
0.02]
• Measurement of 760 ° C using J-type thermocouple with NI 4350 and
accessory (cold-junction sensor) at 38 ° C; filter setting of 10 Hz:
accuracy is 0.73 ° C as a result of
[0.42 ° C + (38 ° C – 35 ° C)
×
0.02 + 0.25 ° C]
• Measurement of 1 V using 1.25 V range, filter setting of 60 Hz at 28 ° C
ambient temperature after 90 days of calibration with auto-zero; at 0 V
common-mode voltage:
accuracy is 119
µ
V as a result of
[1 V
×
0.0101% +18
µ
V]
• Measurement of 1 V using 1.25 V range, filter setting of 60 Hz at 38 ° C
ambient temperature after 90 days of calibration, with auto-zero; at
0.5 V common-mode voltage:
accuracy is 139
µ
V, as a result of
[1 V
×
0.0101% +18
µ
V + (38 ° C – 35 ° C)
×
{1 V
×
0.0004%/ ° C + 1
µ
V/ ° C}+ (0.5V/10
100/20
)]
Analog Input
Input Characteristics
Number of channels................................16 differential
or 14 thermocouple
Digits ......................................................5 1/2
Type of ADC ..........................................Sigma-delta
ADC resolution.......................................24 bits, no missing codes
Calibration cycle.....................................1 year