The National Instruments PXI-4350 is a 24-bit data acquisition module designed for high-precision measurement of thermocouples, DC voltage, resistance, strain, pressure, and load in structural testing and monitoring applications. This PXI-compatible instrument combines 16 differential analog input channels with programmable bridge excitation and integrated signal conditioning to deliver accurate readings across demanding industrial and laboratory environments.
Technical Specifications
Analog Input
• 24-bit analog-to-digital converter
• 16 differential analog input channels
• Single-channel reading rates: 10, 50, and 60 readings/s
• Multi-channel reading rates: 2.8, 8.8, and 9.7 total readings/s
• ±42 V overvoltage protection
• Per-channel low-pass antialiasing filters
• Digital noise rejection at 50, 60, and 400 Hz (selectable)
• Software-selectable ground referencing per channel
• Per-channel open-thermocouple detection with +2.5 VDC bias through 10 MΩ resistor
Bridge Excitation and Resistance Measurement
• Programmable bridge excitation for strain gauges, pressure sensors, and load cells
• On-board bridge completion circuitry
• 25 µA precision current source for RTDs and thermistors (up to 600 kΩ total system resistance)
– Key Features
• Simultaneous measurement of floating and ground-referenced signals via channel-by-channel ground selection
• Open-thermocouple detection generates rapid reading increase (≥100 mV) upon sensor disconnection
• Per-channel input filtering reduces aliasing and external noise interference
• Direct thermocouple, RTD, and thermistor measurement without external conditioning
– Typical Applications
• Structural health monitoring with strain and load measurement
• Pressure and temperature data acquisition in test environments
• Multi-point thermocouple systems requiring synchronized readings
• Resistance-based sensor excitation and measurement
– Compatibility & Integration
Designed for integration into PXI or CompactPCI chassis as part of the NI 435x family, which spans PCMCIA, USB, PXI, and PCI platforms.
