Choosing an NI Measurement System for Strain, Pressure, Load, or Torque


This document introduces available measurement platforms for strain gages, pressure, load, and torque sensors.


Platforms for Measuring Strain and Bridge-Based Sensors

Compact Measurements

Benchtop or Field Measurements

CompactDAQ is a portable, rugged data acquisition platform that integrates connectivity and signal conditioning into modular I/O for directly interfacing to any sensor or signal. Acquire data from over 60 measurement-specific modules over USB, Ethernet, or 802.11 WiFi. 

  • Multiple timing engines to run hardware-timed tasks at different rates
  • Advanced counter functionality from NI-STC3 technology

What Is CompactDAQ?

Embedded Data-Logging Measurements

CompactDAQ controllers offer a high-performance platform for embedded measurements and data logging. Controllers feature an integrated computer and nonvolatile storage so that CompactDAQ can be deployed without an external computer.

  • Intel multicore processing, up to 32 GB nonvolatile storage, and 2 GB RAM
  • Simultaneous streaming of continuous measurements with sample rates up to 1 MS/s per channel

Learn more about CompactDAQ

Extreme Ruggedness and Advanced Control

CompactRIO is a reconfigurable embedded control and acquisition system. The CompactRIO hardware architecture includes a reconfigurable FPGA chassis and an embedded controller. You can use CompactRIO in a variety of embedded control and monitoring applications.

  • A variety of reconfigurable chassis featuring an FPGA for custom timing, analysis, and control
  • Open embedded architecture with small size and extreme ruggedness

What Is CompactRIO?


C Series I/O Modules With Integrated Signal Conditioning for Measuring Strain

NI 9237 24-Bit Bridge Module  

National Instruments offers the NI 9235, NI 9236, and NI 9237 C Series I/O modules specifically designed for the measurement of strain gages. These bridge modules contain all the signal conditioning required to power and measure bridge-based sensors simultaneously. The NI 9235 and NI 9236 have a higher channel count and include completion for quarter-bridge sensors. The NI 9237 supports up to four full- and half-bridge sensors and can measure from quarter-bridge strain gages using a completion accessory. The NI 9237 can perform offset/null as well as shunt calibration and remote sense, making the module the best choice for low- to medium-channel-count strain and bridge measurements.


NI 9218 24-Bit Universal Analog Input Module

The NI 9218 is a 2-channel universal C Series module designed for multipurpose measurements in automotive, off-highway, and data-logging systems. With the NI 9218, you can measure several signals from sensors such as full-bridge strain gages, accelerometers, load cells, and other powered sensors. It can measure quarter- and half-bridge sensors using a completion accessory. The channels are individually selectable, so you can perform a different measurement type on each channel. The NI 9218 has standard 10-pin LEMO and 9-pin DSUB connectivity for ruggedness and custom cabling.




High-Performance and High-Channel-Count Systems


The PXI platform provides a variety of chassis, controller, and module options that give you the power to create a measurement system that meets your application's specific needs. SC Express strain modules offer up to 0.02 percent accuracy at up to 102.4 kS/s. PXI scales to thousands of strain and bridge-based measurement channels for large applications and provides both wired and wireless synchronization options.

  • Configurable desktop, rack-mount, and distributed multichassis solutions
  • Compatibility with a wide range of sensors and transducers
  • More than 1,500 PXI modules, including CAN, vision, motion, and GPS

Learn more about PXI DAQ

PXI I/O Modules With Integrated Signal Conditioning for Measuring Strain

The SC Express family features PXI Express DAQ modules with integrated signal conditioning for sensor measurements, such as strain gages and other Wheatstone bridge-based transducers.


NI PXIe-4330/4331 8 Ch, 24-Bit Bridge Input Module

The PXIe-4330 eight-channel simultaneous bridge input module offers 24-bit resolution, 0.02 percent accuracy, and can perform quarter, half, and full bridge-based measurements with interchannel skews as low as 5 parts per billion. The PXIe-4330 has a maximum sample rate of 25kS/s per channel sample rate, while the PXIe-4331 has a maximum sample rate of 102.4kS/s per channel. This device provides per channel excitation from 0.625 V to 10 V with remote sensing. Added flexibility, built-in bridge completion, and shunt calibration are software-selectable on a per channel basis.



NI PXIe-4339 8 Ch, 24-Bit Bridge and Voltage Input Module

The PXIe-4339 is an 8-channel universal bridge input module ideal for test cell installations requiring both accuracy and flexibility. Completely configurable through software, each channel is capable of taking bridge-based measurements and direct voltage measurements. Eight input ranges in ratiometric mode and four in voltage mode accommodate a wide variety of sensor types for your changing application needs. Per channel, 24-bit delta-sigma analog-to-digital converters (ADCs) with built in anti-aliasing filtering sample at 25.6 kS/s per channel. The PXIe-4339 also features per channel wide bandwidth analog outputs, programmable excitation, Transducer Electronic Data Sheet (TEDS) support, and digital filtering.



Pressure, Load, and Torque Sensors

National Instruments is partnering with Honeywell to offer a wide range of bridge-based load cells, pressure transducers, and torque sensors. NI has tested each of these sensors and verified them for use with the NI PXIe-4330, NI PXIe-4331, NI 9219, and NI 9237 devices. Each sensor is Transducer Electronic Data Sheet (TEDS) enabled for ease of use.

Pressure Sensors

Honeywell’s absolute, gage, and true gage pressure and miniature pressure sensors are manufactured from the start to meet the most demanding test and measurement specifications in some of the world’s most rugged environments.


Load Cells


Honeywell load cells are designed for high accuracy, even under extreme testing conditions that may affect measurements. The load cells include miniature and subminiature tension/compression and compression-style models that are unmatched in harsh environments with tight clearances or confined spaces.


Torque Sensors


With a tradition of quality and accuracy in torque measurement that stretches back over half a century, Honeywell has spent decades improving and customizing both rotary and reaction torque transducers. All Honeywell reaction torque sensors are machined from stainless steel and temperature hardened for low torsional deflection, as well as temperature compensated for long-term stability.


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