Appendix A
Specifications
©
National Instruments Corporation
A-3
RTD Mode
Excitation current ................................... 0.15 mA ±0.04%, 0.45 mA ±0.2%
Maximum load resistance ...................... 10 k
Ω
Drift ........................................................ 40 ppm/ °C
Lead resistance effect............................. Negligible (4-wire measurement)
Resistance range..................................... 10 k
Ω
, maximum
Strain Gauge Mode
Bridge types ........................................... Quarter-, half-, and full-bridge
Bridge completion.................................. Two 4.5 k
Ω
±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 ................................ V
EXT
/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
Accuracy
2
....................................... 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.
