Output signal from these sensors is the form of voltage or current. We are a group of geotechnical and electronics engineers in the uk with many years of experience throughout the world in design, manufacture and supply of intelligent sensors, data acquisition systems and geotechnical instrumentation. The circuit is amplified by an instrumental amplifier ina125p. Unlike textbased programming languages, where instructions determine program execution, labview uses data flow programming, where the data flow determines execution. Refer to the measuring strain with strain gages tutorial on the ni developer zone website for more information about using strain gauges. In practice, the range of strain gauge resistance is from 30 ohms to 3000 ohms.
If you have changed the palette views from the default settings, some palette paths described in the course may not match your settings. Strain gages return varying voltages in response to stress or vibrations in materials. Resistance changes in parts of the strain gage to indicate deformation of the material. Common strain gauges often have a large thermal output as shown in figure 1. When external forces are applied to a stationary object, stress and strain are the result. The figures and equations in the previous section ignore the resistance in the lead wires of the strain gauge. The pdf toolkit for labview gives programmers the ability to generate professional reports in the standard portable document format pdf directly from labview applications. This solution might also apply to other similar products or applications.
The gauge number is a measure of the thickness of the wire. Measuring strain gauge circuits in order to measure strain with a bonded resistance strain gauge, it must be connected to an electric circuit that is capable of measuring the minute changes in resistance corresponding to strain. Learn how to take strain gauge measurements with strain gauges using. Open labview by doubleclicking the ni labview link on the desktop or navigating to startall programsnational instruments labview 8. Each vi uses functions that manipulate input from the user interface or other sources and display that information or move it to other files or other. Therefore, if we replace r4 in figure 3 with an active strain gauge, any changes in the strain gauge resistance will unbalance the bridge and produce a nonzero output voltage. The model will be placed in a wind tunnel where its performance under simulated wind forces will be.
If the nominal resistance of the strain gauge is designated as rg, then the strain induced change in resistance. Also explore the seminar topics paper on strain gauge with abstract or synopsis, documentation on advantages and disadvantages, base paper presentation slides for ieee final year mechanical engineering me or production automobile students for the year 2019 2020. Wheatstone bridge circuit theory, example and applications. Begin to automate and customize your stain measurements using a builtin example that demonstrates the basics of continuously acquiring data from strain gages. Measurement of strain due to bending and axial loads. External calibration, which a metrology lab typically performs, requires. The wheatstone bridge university of colorado boulder. In a halfbridge, boxes 1 and 2 are strain gages, and the others are resistors 5. Scxi strain gauge application we will use a realworld application to illustrate the use of scxi to acquire strain gauge measurements. Reported in shows products that are verified to work for the solution described in this article. For example, consider the twowire connection of a strain gauge shown in figure 8a. The labview concept ii labview is designed to build graphical user interfaces guis for laboratory instrumentation also called virtual instruments vis. This can be done on the computers in the lab, or any other computer with the current version of labview installed. Labview measurements manual chalmers university of technology.
For a quarterbridge, box 1 is an active strain gage, and all other boxes are fixed resistance resistors. Important information warranty the media on which you receive national instruments software are warranted not to fail to execute programming instructions, due to defects in materials and workmanship, for a period of 90 days from date of shipment, as evidenced. With labview, these equations are included in the convert strain. The task of bonding strain gauges to test specimens may appear to be very simple, but it is not. The while loop is a structure that will continuously execute. Labview strain gage sensor integration this manual. In labview, measurements are set up as virtual instruments vi. Ni strain gauge tutorial free download as pdf file. Labview for you, but to work effectively with the control and measurement system in the lab, you should have a good understanding of how the interface and software work. This course assumes you are using the default installation of labview. Connecting strain gages to a daq device national instruments. While ignoring the lead resistances may be beneficial to understanding the basics of strain gauge measurements, doing so in practice can be very dangerous. Ni compactdaq getting started tutorial page 7 of 17 3. The sccsg series straingauge input modules sccsgxx allow you to take quarter, half, and.
The name bonded gauge is given to strain gauges that are glued to a larger structure under stress called the test specimen. Traditionally used by scientists, engineers and other domain experts to build systems quickly. Measurements i 12 bridge strain gauge labview tutorial duration. Strain gage in this laboratory we design our first electronic device, an electronic weight scale. Technological science 1 strain gauge laboratory report by akash sherchan student i. Measurements i 12 bridge strain gauge labview tutorial youtube. In this lab, the active resistive transducers are the electrical resistance strain gages. Load spectrum there are two methods to compute the load spectrum for a material or component. Measurements i 12 bridge strain gauge labview tutorial. Programmers reference manual, a ni labview instrument driver, and programming examples to simplify writing.
Acquire data from strain gauges in labview nxg youtube. Building an analog circuit to obtain deflection measurements using a strain gage in this experiment, you will build an analog circuit for using a 120. You will then observe the voltage output from your. Now available to all makers professional and hobbyists. Labview strain gauge is not at zero with no load ni. Carya has developed the pdf toolkit so you can design report templates in ni labview software and populate these templates with data from labview applications be it text, numbers, or graphs to generate pdf rep. Refer to the installing labview and nidaqmx document for more information. Measuring strain with strain gauges tutorial developer zone national instruments figure 2.
Wheatstone bridge for strain measurement most commonly for measuring the strain, strain gages are used whose electrical resistance varies with proportionate strain in the device. Vi stands for virtual instrument but labview can be used for much more than virtual instrumentation. May 25, 2017 begin to automate and customize your stain measurements using a builtin example that demonstrates the basics of continuously acquiring data from strain gages. The user interface consists of a block diagram area and a front panel area. Sep 11, 2015 measurements i 12 bridge strain gauge labview tutorial. The latter form of the strain gauge is represented in the previous illustration. The accuracy of these models can be verified through testing.
Ive tried placing one strain gauge in a bridge with three matching resistors whose resistances are. Strain gage clamp the strain gage to the lab bench and use the ohmmeter to determine the resistance ro of the unloaded gage. And lastly though there are many other less common load cell set ups, there is a strain gauge load cell, which is a mechanical element of which the force is being sensed by the deformation of a or several strain gauge s on the element. Bonded metallic strain gauge it is very important that the strain gauge be properly mounted onto the test specimen so that the strain is accurately transferred from the test specimen, through the adhesive and strain gauge backing, to the foil itself. Explore the fundamentals of data acquisition using sensors, ni data acquisition hardware, and labview. Guide to labview and apt page 7 chapter 2 labview programs labview programs are called virtual instruments, or vis, because their appearance and operation imitates physical instruments. The sccsg series straingauge input modules sccsgxx allow you to take quarter, half, and fullbridge configuration strain measurements. Several of hbm s data acquisition systems provide easytouse interfaces when used with the labview software.
How to use the while structure tutorial functions programming structures while loop the while loop structure in labview is the same as a dowhile loop that is used in other languages and requires a termination condition. May 15, 2019 wheatstone bridge for strain measurement most commonly for measuring the strain, strain gages are used whose electrical resistance varies with proportionate strain in the device. If you think youve messed something up, the easiest way to fix it for what were doing today is to start over. Figure 1 shows a strain gage with two electrical leads on the right side.
Measurements manual labview measurements manual july 2000 edition part number 322661a01. Carya has developed the pdf toolkit so you can design report templates in ni labview software and populate these templates with data from labview applications be it text. Measure and record the resistance of each of the gages. Pdf toolkit for labview carya automatisering national. Labview basics instrumentation and control engineering.
Wednesday, december 8 midnight for this homework assignment, you will complete a tutorial on the labview data acquistion software. Use the nidaqmx driver to measure, generate, and synchronize data acquisition tasks. Reported in shows products that are verified to work for the solution described. Signal conditioning is done before interfacing with labview. Use the arrangement that produces the maximum sensitivity. For part 2 of the lab, rx is a standalone coil of copper. Our combined experience means that our equipment can be easily adapted to provide unique solutions to electronic and geotechnical. When using a strain gage, you bond the strain gage to the device under test, apply force, and measure the strain by detecting changes in resistance. Do not save any changes you may have made to the builtin vis were using such as hp34970a initialize. Sccsg series straingauge modules user guide and specifications. Reading a strain gauge signal on labview via arduino ni. Measuring strain with strain gages national instruments.
How to easily integrate hbm s quantumx system with labview by using prepared vi function blocks. The tutorial is installed on the lab computers, and can also be installed on your personal computer along with labview and completed at home. Ni strain gauge tutorial electrical resistance and. I just want to know that which daq card will be suitable for this application i have searched a lot and i am a little bit confused about the chocie of daq card. And lastly though there are many other less common load cell set ups, there is a strain gauge load cell, which is a mechanical element of which the force is being sensed by the deformation of a or several strain gauges on the element. Sketch in your lab notebook a bridge circuit in which the two gages can be used to measure the strain in the beam when it is loaded as a cantilever beam. Strain gages are one of these examples which are used to measure the strain in structures.
My problem lies with acquiring any signal at all with a quarter bridge arrangement. Pdf strain gauge force transducer and virtual instrumentation. Measurements i 14 bridge strain guage labview tutorial. Hi, ive been using labview to acquire signals from a full bridge strain gauge circuit on a steel bar, which thus outputs a signal when i bend it. Use a strain gauge to record the stress on a material or component when performing fatigue analysis. An experimental aircraft model is instrumented with 16 halfbridge, 350. This method is simple, fast, and requires no manual adjustments.
The key component is a strain gage, a resistor that changes its value in response to mechanical stress. Learn the basics of hardware selection, including resolution and sample rate, and the foundation of sensor connectivity, including grounding and wiring configurations. A vis can read out to a single sensor, emulate the frontface of commercial devices or control large integrated systems. The compuscope labview sdk for windows allows gage users complete control of. An original strain gauge force transducer and virtual instrumentation in a ni and labview environment are used, conforming to a rigorous clinical protocol to. Labview strain gage sensor integration on material. A strain gauge sometimes refered to as a strain gage is a sensor whose resistance varies with applied force. All of our controllers are supported by unified pc based user and. We will also use an instrumentation amplifier to gain up the signal. The metallic strain gauge consists of a very fine wire or, more commonly, metallic foil arranged in a grid.
Simply close all your labview windows, saving only your work, and exit labview. May 25, 2018 labview strain gauge is not at zero with no load. Strain gauge seminar report, ppt, pdf for mechanical. This document provides stepbystep instructions for wiring and configuring your daq device for strain gage measurements. The explanation about strain gauge function, calculation, application, signal conditioning from national instruments. Labview is a graphical programming language that uses icons instead of text lines to create applications. You will demonstrate your new programming skills by completing selected exercises from an ni training course, found here. Hi, i am going to interface 16 strain gauges with labview.