Faced with the challenge of testing a large and complex on‐highway vehicle, engineers from Integrated Test & Measurement knew it would take hundreds of channels…
The most common strain gauge installation configuration is a 350 ohm, quarter bridge. Quarter bridge installations a generally the easiest and most economical installation for determining structural strain levels. In the quarter bridge configuration a single element strain gauge is mounted in the principle axial or bending strain direction.
One tool that our engineers and technicians use to collect data from 350 ohm, quarter bridge strain gauge installations is the NI-9236 strain module. The NI-9236 is an 8-Channel C Series 350 ohm strain/bridge input module that is used with a CompactDAQ or CompactRIO chassis. This module provides bridge excitation (3.3 Volts), Wheatstone bridge completion, shunt calibration, and filtering for 350 ohm quarter bridges. Use this module in conjunction with a CompactDAQ chassis and iTestSystem engineering measurement software to collect synchronized, high-speed (10kHz) structure strain data.
A case study describing a strain gauge DAQ system used to validate several new designs of a heavy lift lattice boom crane to comply with SAE J987 standards.
Our iTestSystem customers who routinely acquire data with high channel counts and data from full-bridge transducers recently requested that we update the sensor auto-zero utility to improve test setup efficiency. In the latest version of iTestSystem, we updated the sensor auto-zero utility to include all channels that use the From Custom Scale option. This update enables users to quickly adjust selected channel offsets with only a few mouse clicks.
One of our test engineers recently used this feature to test and calibrate a new load cell design for measuring loads in a manufacturing process. He was able to quickly calibrate and zero the strain gauges along with a calibrated load cell and a pressure transducer prior to testing and before each directional test. The offset values are included in the calibration data files for traceability.
Contact Information: For more information about this update or iTestSystem contact:
Chase Petzinger – Integrated Test & Measurement (ITM), LLC. Email: email@example.com or Phone: 1.844.TestSys
Image1: Shaft torque strain gauge installation example for field testing
Our engineers and technicians have epoxied, soldered and spot welded strain gauges for applications ranging from high temperature exhaust systems to miniature load cell measurements. Every application requires a unique understanding of the strain measurement requirements including installation environment.
If the strain gauge installation is to survive in the field you must plan for the conditions it will undergo. Three important variables that you should account for are temperature range, liquid exposure, and potential impact forces. These variables determine the type of strain gauge, epoxy, solder, wiring, coating, and impact/wear protection to use in the application. The table below shows which variables affect your installation choices.
Table1: Strain gauge installation variables
For more information about ITM’s strain gauging services contact Ryan Welker at email: firstname.lastname@example.org or phone: 1.844.837.8797 x702
ITM | Integrated Test + Measurement
227 Water Street, Suite 300
Milford, OH 45150
Email: ITM Sales
ITM provides software development, structural and mechanical testing services, industrial monitoring, strain gauging, and data analysis solutions to clients on six continents. ITM is a recognized National Instruments Gold Alliance Partner.