Appendix A Specifications
© National Instruments Corporation A-3 SCXI-1121 User Manual
RTD Mode
Excitation current...................................0.15 mA ±0.04%, 0.45 mA ±0.2%
Maximum load resistance...................... 10 kΩ
Drift........................................................40 ppm/ °C
Lead resistance effect.............................Negligible (4-wire measurement)
Resistance range.....................................10 kΩ, maximum
Strain Gauge Mode
Bridge types........................................... Quarter-, half-, and full-bridge
Bridge completion..................................Two 4.5 kΩ ±0.05% ratio
tolerance resistors
Excitation voltage.................................. 3.333 V ±0.04% or 10 V ±0.2%
Resistance range.....................................120 Ω, minimum at 3.333 V
800 Ω, minimum at 10 V
Half-bridge voltage................................ VEXT/2 ±0.04%
Cold-Junction Sensor 1
SCXI-1320 and SCXI-1321
Accuracy.........................................1.0 °C over 0 to 55 °C
Output............................................. 10 mV/°C
SCXI-1328
Accuracy2 .......................................0.35 ° from 15 to 35 °C
0.65 ° from 0 to 15 ° and
35 to 55 °C
Output............................................. 1.91 to 0.58 V from 0 to 55 °C
Output at 25 °C............................... 1.25 V
1 Located on the SCXI-1320, SCXI-1328, and SCXI-1321 terminal blocks
2 Includes the combined effects of the temperature sensor accuracy and the temperature difference between the temperature
sensor and any screw terminal.