The NI SCXI-1520 is an 8-channel universal strain and bridge input module engineered for high-accuracy signal conditioning of strain gauges, load cells, pressure transducers, force sensors, and torque sensors. It supports quarter-, half-, and full-bridge configurations across 120 Ω and 350 Ω impedances, with per-channel programmable settings for gain, filtering, excitation, and calibration. The module integrates into SCXI chassis and connects to National Instruments DAQ devices via NI-DAQmx driver software.
Technical Specifications
Input Channels & Signal Types
• 8 analog input channels
• Quarter-bridge, half-bridge, and full-bridge configurations (120 Ω, 350 Ω)
• Compatible with strain gauges, load cells, pressure transducers, force sensors, torque sensors
Signal Conditioning
• Programmable amplifier: gain from ±10 mV to ±10 V, up to x1000
• 4-pole Butterworth lowpass filters with selectable bandwidths: 10 Hz, 100 Hz, 1 kHz, 10 kHz; bypass mode available
• Software-selectable excitation: 0 to 10 V per channel, 17 programmable voltage levels
• Remote sensing circuitry for lead resistance compensation
• Half-bridge completion built into module; quarter-bridge completion via SCXI-1314 terminal block
• Two shunt calibration circuits per channel
• Automatic software-configurable null compensation for bridge offset
• Simultaneous sample-and-hold for coordinated multi-channel acquisition
Measurement & Calibration
• 49 programmable input ranges from ±10 mV to ±10 V
• Onboard reference for automatic calibration in variable environments
• NIST-traceable calibration certificate included
• Calibration constants stored on module EEPROM
• Software-configurable offset nulling and shunt calibration via NI-DAQmx
Scanning & Data Acquisition
• Random scanning: acquire selected channels in any order to reduce scan times
• Multiplexed mode: channels routed to single DAQ input
• Parallel mode: each channel routed to unique DAQ analog input (NI-DAQ 7)
Protection
• Overvoltage protection: ±35 V
– Key Features
• Per-channel software configuration for maximum measurement flexibility
• Excitation capable of driving 350 Ω full bridges without external amplification
• Simultaneous sampling via track-and-hold circuitry
• Automatic field calibration in changing thermal or environmental conditions
– Typical Applications
• Structural testing and monitoring
• Materials research and characterization
• Industrial load and force measurement
• Pressure and torque transducer systems
• Field-deployed sensor networks requiring automatic recalibration
– Compatibility & Integration
• NI-DAQmx driver software
• LabVIEW, LabWindows/CVI, Measurement Studio
• Windows 2000/NT/XP (for NI-DAQ 7)
• SCXI chassis integration
