Vishay measurements group strain gage website strain gage installation manual me 302 lab schedule week dates lab topics assignment due dates 1 117 121 first week of semester no lab classes 2 124 128 overview, safety, uncertainty analysis statistical analysis 3 1 24 tensile testing data reduction overview homework 1a and 1b 4. In this case, it is possible to compare the strain measurements with calculated values. The strain gauges used for measurement of deflection of a beam subjected to different point and uniformly distributed loading. This solution might also apply to other similar products or applications. Students will take measurements from and calibrate a strain gage mounted on a cantilever beam and placed in a quarterbridge wheatstone configuration. The mechanical strain experienced by the test specimen, and thus also by the strain gauge, gives rise to resistive strain of the gauge element. I have to attach a strain gauge on a aluminum tube to measure 3d forces on it. Connect the data cable between the strain gauge amplifier and the port on the back of the cantilever beam. By using the ni elvis ii prototyping board and labview, students can automate a load reading from a strain gauge while learning how to build a simple. Learn how to take strain gauge measurements with strain gauges using the builtin. This ratio is known as the gauge factor and is approximately equal to 20 for foil. November 7, 2008 ryan carmichael swarthmore college. Plug the power cord from the bottom rear of the 2311 into the bench power strip. A load cell works by converting mechanical force into digital values that the user can read and record.
Sensorcloud provides vis which allow your labview applications to communicate with sensorcloud. For use with d6127, d6129, dbrw, ad6856, d6550 or d6745. Smyser is an assistant academic specialist and the lab director of the. In this laboratory, i successfully installed a cea240uz120 student strain gage onto a 6061 aluminum beam. In this lab, the active resistive transducers are the electrical resistance strain gages. Connect the bendix connector attached to the wire junction to the rear of the 2311. As an extra credit exercise, you will write a labview program to compute the power. Labview sdk lordmicrostrainsensorcloud wiki github. Click on windowsshow diagram to display your block diagram. Before performing this lab you must be familiar with. However, any changes in temperature will affect both gauges in the same way. Labview, a user interface program, is used to translate changes in wire resistance on the strain gage into a numerical value, in microstrains. You will need to run the program to auto tune the bridge once again.
The gauge is attached to the object by a suitable adhesive, such as cyanoacrylate. Strain gage in this laboratory we design our first electronic device, an electronic weight scale. Labview graphical programming4th edgary and richard feb. Acquire data from strain gauges in labview nxg youtube.
A strain gauge also spelled strain gage is a device used to measure strain on an object. Connecting strain gages to a daq device national instruments. They make it simple to authorize devices, register sensors, and send data from within your labview code. In order to compensate for such changes which the instrumentation would interpret as mechanical strain the gauge itself should be chosen, if possible, as one having temperature compensation for the material being tested. 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.
I will use a wheatstone bridge for each strain gauge. Pdf strain gauge force transducer and virtual instrumentation. Labview strain gage sensor integration this manual. This paper describes the implementation of labview, in an experiment in a. Technological science 1 strain gauge laboratory report by akash sherchan student i. Measurements i 14 bridge strain guage labview tutorial. 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.
Building a low cost strain gage load cell amplifier the. We will also use an instrumentation amplifier to gain up the signal. Compatible with labview, dasylab, matlab, origin, c and visual basic software. With a resistance type strain gage, strain is measured by detecting the change of resistance in. In this laboratory, you will build an analog circuit that will enable you to measure the voltage output of a strain gage mounted on a cantilever beam metal beam to. Strain gauge load cells offer accuracies from within 0. Comparing strain gage measurements to force calculations. Rg is the strain gauge nominal resistance value in ohms. As an extra credit exercise, you will write a labview program to compute the power spectrum of the output from your strain gage circuit before and after the lowpass filter. Applying strain gauges properly to get good data is. Mcgraw hill college division 2 montero w et al, 2011, uncertainties associated with strain measuring systems using resistance strain gauges, j. Strain gage sensor system background reading please read the following material prior to this lab. With labview, these equations are included in the convert strain. Then they will measure the natural frequency of the beam assembly by applying a fast fourier transform to the response of the beam due to an impulse.
They are highly accurate and reliable over a long period of time. Recent strain gage measurement applications by simutech include automotive radiators, a helicopter airframe, a forging press, a. Ruge in 1938, the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern. Strain measurements are applicable to a wide variety of structures including industrial equipment, turbomachinery, aircraft, piping, automotive components and electronics. R, and a second gauge is placed transverse to the applied strain. The dscusb strain gauge to usb converter is a compact, high performance strain gauge digital signal conditioner with usb connectivity aimed at applications which require highaccuracy measurement repeatability. This parameter is only required for certain bridge configurations. The fx1901 is an inexpensive 1% strain gauge that can be used for a variety of applications. Laboratory 3 strain gage sensors national instruments. Lab 4 strain gage university of california, berkeley. The special alloys used in strain gauges exhibit a nearlinear ratio between their resistive and mechanical strains. The daqmx does have two vis for this, daqmx perform bridge offset nulling calibration. Generalpurpose gauges are available in the following patterns. So the main attractive feature for the customer is the offset nulling and shunt calibration.
It can be used to calculate forces, pressures, displacements, and a whole variety of other mechanical material properties. Use the arrangement that produces the maximum sensitivity. Dont use this circuit for instrumentation, there is no signal conditioning for the. Design, build and test a force sensor using strain gauges are provided, as well as development of the appropriate combination of strain gauges with other electrical components to obtain an electric voltage or current representing tensile, compressive or bending. This lab explores the concept of strain measurement using a strain gage. Gauge behavior transverse sensitivity use of the fe model. The focus of this thesis is the design of a vi that will collect and plot force and moment data from a six component strain gauge balance and yield real time, nondimensional, force and oment coefficients in six degrees of freedom.
Begin to automate and customize your stain measurements using a builtin example that demonstrates the basics of continuously acquiring data from strain gages. 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. Furthermore strain gages have a low resistance from 60 to 350 ohm depending on the models and feeding load cells with high excitation will heat strain gages up. Measurement of strain due to bending and axial loads. Me 302l cee 370l materials mechanics laboratory manual. Strain is the 2 nd most common physical sensor measurement in the world behind temperature.
The bondable foil strain gauges manufactured by our micromeasurements are available with thousands of possible combinations of grid alloys, pattern designs, gauge lengths, backing materials, resistances, and optional features. Static strain measurement cantilever beam objectives. The key component is a strain gage, a resistor that changes its value in response to mechanical stress. Push on the beam so it deflects and make sure that the resistance changes. In this part there will be a use of a strain gauge device which experiences a change of electric resistance when it is strained. A rugged abs ip50 enclosure makes this usb load cell converter suitable for all environments.
The inner working of a load cell differs based on the load cell that you choose. How to programmatically create a strain gage calibration. Figure 1 shows a strain gage with two electrical leads on the right side. This experiment is dedicated to study the main objective of resistance strain gages. They are designed to work for desktop applications and embedded devices lik the ni compactrio. Strain gauges are available commercially with nominal resistance values from 30 to. Labview for everyone graphical programming made easy and fun, third edition. Strain gauge scales use no springs and use a strain gauge transducer to measure the weight and display it digitally. I am using the strain gauge vi for labview, on the myrio. Measurements i 12 bridge strain gauge labview tutorial duration. This laboratory experiment is intended for students to. All of our controllers are supported by unified pc based user and.
Therefore, the strain has little effect on the second gauge, called the dummy gauge. Strain gage measurement strain gage installation simutech. The metallic strain gauge consists of a very fine wire or, more commonly, metallic foil. For th is lab, materials will assu med to fall in to the linear elastic region, using youngs modulus to relate stress and strain 1. Hello, i have a requirement to build a strain data acquisition systems using labview with all the signal conditioning facilities available with pxie4331. Begin to automate and customize your stain measurements using a builtin example that demonstrates the basics of continuously acquiring data from strain. In fact you cannot use strain gage load cell without instrument amplification, since the sensitivity of the bridge is really low.
Strain gages return varying voltages in response to stress or vibrations in materials. Single opamp amplifier to adapt a quarter bridge strain gauge to the analog input of an arduino micro controller. Now i want some information about strain gauge calibrations. K is a constant known as the gauge factor and is the relative strain.
Associated with the strain gage is a measurement system. The default is 120 gf is the gauge factor of the strain gauge v is poissons ratio. Strain measurement in a simply supported beam asee. In this paper, experimental setup for stress measurement using ni labview has been presented. This is a novel medical application that combines the strain gauge sensing technology, applied on a cantilever beam as an. In a halfbridge, boxes 1 and 2 are strain gages, and the others are resistors 5. Because the temperature changes are identical in the. It is designed to measure, condition rectify and filter, and display the feedback signal derived from ac bridge strain gauge systems. Digitize any combination of channels at 166,000 samples per second aggregate.
1615 527 811 1125 100 1476 1003 724 1343 875 994 36 57 820 83 1130 158 665 366 545 935 1331 782 1495 113 1186 1128 1426 817 1232 1183 507 377 1298 205