The Challenge:
Designing a reliable and accurate structural monitoring system for oil and gas pipelines subjected to internal pressure and environmental stresses. The system must deliver real-time strain data from multiple locations along the pipe while maintaining integrity over long cable distances.
The Solution:
A modular data acquisition system using NI cDAQ-9174 and NI 9236 modules, integrated with strain gauges in a quarter-bridge configuration, enabled by Haliatech. The setup reads strain across multiple biaxial gages (0° and 90°) attached to the pipe. A dedicated LabVIEW-based interface visualizes strain data in real-time for structural analysis and reporting.
Pipeline systems are subjected to a variety of stresses, including internal pressure, temperature fluctuations, and external loads from installation or geological movement. Accurately capturing the mechanical response of the pipe material under these conditions is crucial for maintaining structural safety and predicting potential failures.
To address this, Haliatech developed a strain measurement system comprising:
- NI cDAQ-9174 USB Chassis with NI 9236 strain modules (8-channel, 350 ohm quarter-bridge support)
- Strain gauge sensors (350 Ohm) configured as biaxial gauges at 0° and 90° orientations
- A custom LabVIEW application for real-time data visualization, analysis, and automated report generation
- Control and Testing Rooms connected via 3–5m shielded strain gauge cables
Key Features:
- Read Strain Data – up to 16 gages monitored in real time
- Live Data Visualization – dynamic strain graphing interface with LabVIEW
- Report Generation – export of test reports and historical analysis for engineering records
- Modular Hardware – expandable system using NI CompactDAQ platform
Real-World Implementation
The system is deployed in a controlled test environment:
- Testing Room: A pipe section equipped with 8 strain gauges (4 sets of biaxial pairs) spaced evenly to capture deformation patterns along its 3-meter length.
- Control Room: Hosts the NI cDAQ system and PC interface, where engineers can observe strain behavior live and export test results.
The strain gauges, connected through quarter-bridge configurations, send analog data to the NI 9236 module, which digitizes and transmits data to LabVIEW for processing.
The strain measurement interface includes:
- Real-time strain chart updates
- Zeroing and calibration functions
- Individual strain channel monitoring
- Exportable test logs
Benefits
- Precision Monitoring: Captures microstrain changes as small as ±0.001 με
- Remote Setup: 5-meter cable tolerance enables separation of harsh test conditions from operator workspace
- Scalability: Add more channels or upgrade to cDAQ-9178 for 8-slot expansion
- Compliance: Assists in verifying pipeline designs meet safety standards before field deployment
Conclusion:
This strain monitoring solution empowers pipeline engineers with accurate, real-time mechanical data essential for evaluating structural performance. By leveraging NI’s high-precision data acquisition hardware and LabVIEW visualization tools, Haliatech offers a complete system for stress analysis in critical oil & gas infrastructure.
References:
What Is CompactDAQ?
https://www.ni.com/en-us/innovations/compactdaq.html
NI CompactDAQ Overview
https://www.ni.com/en-us/shop/hardware/products/compactdaq.html
NI 9236 Datasheet – 8-Channel Strain/Bridge Input Module
https://www.ni.com/en-us/support/model.ni-9236.html
Strain Gauge Fundamentals
https://www.omega.com/en-us/resources/strain-gages
Understanding Quarter-Bridge Strain Gauge Measurements
https://www.ni.com/en-us/support/documentation/supplemental/06/quarter-bridge-strain-gage-measurements.html
LabVIEW for Measurement and Control
https://www.ni.com/en-us/shop/labview.html
Haliatech – Improving Confidence in Data Integrity with TSN
https://haliatech.com/electronics/improving-confidence-in-data-integrity-with-time-sensitive-networking-technology/
Time-Sensitive Networking (TSN) Explained
https://www.avnu.org/what-is-tsn/
