Appendix A
Specifications
©
National Instruments Corporation
A-5
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 [directly from table]
•
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 1V 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 1V 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
PCMCIA ......................................8 differential or 6 thermocouple
ISA and USB................................16 differential or
14 thermocouple
Digits ..................................................5½
Type of ADC ......................................Sigma-delta
