The NI PCI-4351 is a high-precision data acquisition card that combines multifunction measurement capability with direct integration into PCI-based computer systems. It delivers accurate temperature, voltage, and resistance measurements across 16 differential analog inputs or 14 thermocouple channels using a 24-bit sigma-delta ADC. The card supports thermocouples, RTDs, thermistors, and DC voltage measurements with 5½-digit precision, making it ideal for research, development, and industrial testing environments requiring demanding accuracy.
Technical Specifications
Measurement Channels & Input Types
• 16 differential analog inputs or 14 thermocouple channels
• DC voltage measurement within ±15 V range
• Temperature measurement via thermocouples, RTDs, and thermistors
• Resistance measurements using built-in precision current sources
• Current measurements with external shunt resistors
• Chromatography measurements
ADC & Accuracy
• 24-bit sigma-delta ADC
• Thermocouple (J-type): ±0.42 °C
• RTD: ±0.12 °C
• Thermistor: ±0.03 °C
• 5½-digit voltage measurement resolution
Acquisition Rates
• Single-channel: 10, 50, and 60 readings/s
• Multiple-channel: 2.8, 8.8, and 9.7 readings/s total
Excitation Sources
• 25 μA precision current source (supports up to 600 kΩ system resistance)
• 1 mA precision current source (supports up to 15 kΩ system resistance)
Protection & Signal Conditioning
• ±42 V overvoltage protection on input circuitry
• Digital filters reject 50, 60, and 400 Hz noise automatically
• Per-channel open-thermocouple detection with +2.5 VDC/10 MΩ test circuit
• Software-selectable per-channel ground referencing
– Key Features
• 8 TTL-compatible digital I/O lines (8 mA sink/source per line)
• 480 mA power draw at +5 V
• Flexible channel configuration supporting floating and ground-referenced signals
– Typical Applications
Temperature monitoring systems, precision sensor characterization, thermal testing protocols, resistance measurement networks, and data logging in laboratory and manufacturing environments.
– Compatibility & Integration
PCI card format; digital I/O requires TBX-68T or CB-68T terminal blocks.
