Negative results with strain gauges

Similar Questions

• With the help of the strain gauge convert read vi

  I'm having trouble with the wiring of the strain gauge convert reading vi. Are there examples of this vi showing how to connect?

  Thank you

  HS

  Have you checked the help file to this topic?

  http://zone.NI.com/reference/en-XX/help/371361G-01/lvinstio/conv_strain_read/

  There seems to be some examples of stock to use, but the help files for these screws can be VERY useful.

• Calibration with NI9237 and NI9944 strain gauge.

  Gentlemen.

  I have a cDAQ9172 OR with NI9237 and the bridge 1/4 NI 9944. Practically, I'm working on measures of strain gauge issues using a strain than 120 ohms connected to the NI9944 to build the bridge half happening inside of 9237. I have a continuous doubt how is the calibration for the strain gauges. The manual speaks of a shunt resistance which, in the case of NI9944, is already in the system. The manual says that I don't have the shunt resistance external nee. It is clear.

  My question is this:

  the menu for calibration requires a resistance value that I don't know, I'm leaving in the value proposed by the menu of NOR. The strain gauges takes easily compensate, so I always have to recalibrate the channels in the NI9237. Is this normal? Can a (application to 2.0 V strain gage) voltage of 2.5 [V] generates a continuous drift of the measure?

  Strain gauges are: EA-06-125BT-120

  Hi cgenco,

  Because the NOR-9237 with 9944 uses an internal resistance for shunt calibration, you need not to worry about the value of the shunt resistance. Take a look at the following article that specifies how connections are made. Calibration article will show you the basics behind how to exploit.

  Also, since there is a ratiometric measurement, the voltage is 2.5V shouldn't matter as long as your pawn takes care of everything.

• How do I program labview to read a full bridge strain gauge placed at an angle of 45 degrees to measure the torsional deformation?

  Hello

  Currently, I'm trying to convert the reading of the strain gauge allows to get readings of the strain of a game of strain gauges of configuration of full-bridge at an angle of 45 degrees on a hollow cyllinder. It is set at 45 degrees, because we are trying to get traction and compression strains resulting from the application of the twist, or a moment of torsion, to the cyllinder hollow. Finally, we want to convert these readings of strain in order to get the couple. Our problem is that full-bridge options to convert the strain gauges appear only apply to configurations 0 or 90 degrees. My question is how can I take my current VI and set it to take readings of the strain of an alignment of 45 degrees. Also suggestions on how to add couple of this VI measures would be appreciated. We have scoured the site, but we are very new to Labview.

  Thank you!

  

  This is not a very good example, they show.  Full-bridge 1 will also read the constraint of torsion.  Full-bridge 1 is for any configuration where you get 2 gauges of tensile and compression 2 meters and you expect roughly equal magnitudes.  With a twisting bridge, the only thing you need to do is to make sure that the wiring and pay attention to the numbering of gage.  Think just mentally on what measurers are in tension and in compression as you twist the stem or tube.

  If you're wrong, you pretty much know immediately because you will see very little change in the output when you go to the torsion of the shaft because the templates of traction and compression will liquidate cancel each other in the bridge rather than expand their effects.  To fix it, all you will need to exchange a few threads to effectively rewire the bridge correctly.

  Good luck in your project.

• Measure the voltage of strain gauge

  I have connected my 9237 to a 9945. I use a 350 ohm strain gauge. I have the voltage set to 2, 5V Max is there a way to measure physically to be sure that it is 2.5V? Also, in my vi I use a DAQmx create function of the channel. I want to add another channel for this but can't see how to do it.

  Thank you

  HS

  Hi, Harry, it's Paul with engineering Applications to the OR.

  My first question is why you are wanting to physically measure the voltage?

  If you are wondering how that tension may vary, it is limited by the maximum capacity of 150mW of your device, as explained here: http://digital.ni.com/public.nsf/allkb/7CBC67482CC9FB318625758C0048FF73?OpenDocument

  If you want to continue to measure externally, you have a few options.  You can use another DAQ hardware to measure the voltage, or you can use another external device, like a digital multimeter.

  If you want to see in the excitement that is actually supplied LabVIEW code, you can use the node property DAQmx 'Value of real excitement'.

  As far as playback of multiple channels, theres two ways you can go about it.  If your channels are sequential and all have the same settings, then you can change your name of the physical channel to something like 'Dev1/ai0' to ' Dev1 / ai0:3: to specify the first 4 channels.»  Alternatively, if you wanted to select non sequential channels, you can chain create channel set tasks, as long as they are of the same type of task (AI voltage, etc.) and the same device, as shown below.

  

  Let us know if you have any other questions.

  Kind regards

  Paul

• To win a set of multiple strain gauges

  Hello

  We are using several gauges of constraint and "Calibration of Shunt DAQmx Perform (strain) .vi" for calibration of shunt. We want to output, gain adjustment, used by the "Shunt DAQmx Perform (strain) .vi calibration" for each caliber. We've had some success using a property node (see attached pictures 1 and 2); However, when we try to use the same method to achieve adjustment gain, any other strain gauges (picture 3), the readings are always 0 (visible) in image 2.

  If someone could give some insight on how to get the gain adjust for several gauges, it would be highly appreciated.

  See you soon

  Bart Scicchitano

  (using his account of supervisors with his permission)

  Hi Bart,.

  You can be is 0 because there are several channels in the same task, then the property node does not know the following. You can set the active channel by using the Active Channel property node. Place a DAQmx channel property node and select ActiveChan from the drop-down list. Give it a try and see if you can read the multiple factors of gain.

• Reading of several strain gauges (10 to 20 strain gauges)

  I work on my ME senior project and I try to read the pressure on the suspension triangles and the stems of thrust for vehicle FSAE of our school. I want to read and data log 5 readings of strain by corner so 20 strain readings altogether. The system must be compact enough to fit in the car.

  From my research, each strain gauge will have 4 analog inputs (2 analog channels, one for the constraint of voltage reading and one for the voltage of reading). It would mean I would need 80 analog inputs to achieve this and I can't find a proper data acquisition.

  I'll try to find a good solution cheap and easy to achieve and seeks in things like multiplexers to change string beetween to demand less entered DAQ, but it becomes very compliated.

  Can anyone recommend a good cheap and easy solution to accomplish this task?

  Reference example of strain canal bridge: (http://zone.ni.com/devzone/cda/epd/p/id/6417)

  Thanks in adance for any input!

  You must first complete circuits bridges.  If you plan to use a unique to each place active extensometer, then you connect the other 3 elements (resistors or dummy gauges) complete form bridges.

  If you had a handful of bridge circuits, the U3 would be the least expensive option.  With a U3 - LV, you need 1 LJTick-InAmp for each circuit of 2 bridges, which would be about $170 to manage 2 bridges.

  For circuits of 20 bridges, however, the cheapest option will be a U6/U6-Pro with the Mux80.  For a little more, you can go with the T7/T7-Pro for Ethernet and WiFi in addition to USB connectivity.  These solutions will be about $450 - $650 and give you 84 analog inputs (you need 40 analog inputs for your 20 differential signals, most at least 1 analog input to read the voltage).

  What is the rate of scanning max you need?

  There are some more details that we can get in, so you can send us an email to talk more.

• As a strain gauge measure weight?

  Hello everyone. I am doing a project in Labview and I have to measure the weight of the different animals. I was thinking a strain gauge to measure with the NOR-9237 as DAQ hardware. Can it happen? I downloaded a system image.

  Thanks in advance

  You're still more general. If you want us ethe USB daq, you should have the driver for the acquisition of data so that you can detect the hardware in the window of measurement and Automation Explorer and then take an example of simple data acquisition and trying to work around. Create a task for the channel you are going to connect to the strain/in² and then configure the channel type and etc, and then you're good to go with the stuffs of base (DAQ assistant) in LabVIEW.

• Strain gauge: calibrate, relaxation and to write to the file

  Hello

  I'm new to labVIEW please bare with me.  My title says I'm trying to do.  I want to capture data from strain gauge using a trigger and write data to a file.  However, I also want to be able to calibrate the strain gauges.

  My attached program reads the data correctly with relaxation and stores it in a file, but it does not calibrate properly.  If I run the program several times and press the button "calibrate" each time, finally get gauges calibrated after two or three iterations.

  Is it possible to change the program so that the gauges are calibrated and then data can be triggered and written to the file?

  I'm using LabVIEW 8.6 and NI-DAQmx 8.8.

  A screenshot of the front panel is also attached.

  So I thought about it, but I'm not completely sure why it works.  I didn't remove the loop condition around the calibration block and the program works beautifully.  All I have to do is wait about 20 seconds before I hit the trigger for the calibration to be completed, and my gauges will be calibrated when I pull the trigger.

  This program works very well for this application.  However, it is difficult to change because all parameters are constant in the block diagram.

• Compensation of temperature for the strain gauges

  I'm trying to compensate for the effects of temperature on an extensometer placed on a sample of carbon fiber.  The sample will be only responsible uniaxialement.  The temperature is a major concern here, for an electrical current will be executed by him for purposes of measurement, which should also heat the sample.  I read in the document 'Strain gauges measure' on the website of NOR (http://www.ni.com/white-paper/3642/en), but he speaks with a Measurer of mannequin, he speaks not just how this second pledge, placed perpendicularly to the axis of the applied force, we are not talking of how connect to the strain gauge module , in my case the NI 9235, to use for temperature compensation.  My first thought was just connect each pledge to the module as their own separate channels, using quarter-bridge in the LabVIEW software set up, calibrate the two gauges while not external physical load or temperature effects are applied, and then, after the test, by subtracting the measure pledge Sham in the values of assets pledged.  But then I started wondering, is there a better way to do this?  Can I use the half-bridge configuration, or some other configuration with the 9235 to automatically merge the readings two pledge during the test?

  I'd appreciate it really any advice that anyone can give me on this.  I don't want to build my own external wheatstone bridge (other than the built-in NI 9235), and I would like to make these measurements as accurate as possible.  I have also considered the possibility of the compensators measurers, but I don't think this would be applicable in this case, the complexity of the matter - being a composite.

  Hello WyoEng,

  You want to use the temperature compensation is referred to as a quarter bridge II configuration (image below). This configuration is very similar to a half of the bridge, while the second element (R3) is inactive because it is placed transversely to the direction of the load, without strain and in the same location the active gage (R4) to take account of thermal affect.

  

  NI 9235 supports only a quarter bridge I configuration for measures of constraints.  You will get an error if you try to use this module for any other configuration of pledge of strain that is not quarter bridge I. Thus, active policy that you asked to use two channels to read the pledge and the dummy gage will be the best option to use NI 9235 to compensate for thermal effects on your extensometer.

  Another option would be to look on the NI 9237 which supports a quarter bridge II configuration.

  Best regards

  Izzy O.

  Technical sales engineer

  National Instruments

  NI.com/support

• Several strain gauges

  Hello

  I'm trying to run a simple application, where several strain gauges is to read, nothing fency. I use an indicator of the gauge to display the strain reading well. The problem is when I connect multiple calibers, I do not know how to assign the individual indicators to different strain gauges, so all my indicators in gauge end by showing the same value. What I want is the different gauge indicator show the succession of different strain gauges.

  Material: Labview 8.5.1, block SC-2345, CSC-SG01 measuring module connector, card data PCI-6251 acquisition.

  Thank you

  Sine

  On the block diagram, go to Express---> Signal handling.

  You will see some functions to merge and split signals.  It is mobile control.  You can enter the bottom and drag them down, so you can create multiple entries (Merger) or outputs (for split) as needed.

  Eventually you want to get a way to use the Express VI, but they are good for a beginner to get started quickly.

  To learn more about LabVIEW, I recommend watching the LabVIEW tutorials online
  LabVIEW Introduction course - 3 hours
  LabVIEW Introduction course - 6 hours

• When I subtract two numbers DBL and try to compare the result with another DBL, it fails

  I found a curious problem with subtraction and compare numbers DBL in LabVIEW (8.6). Here's how it works:

  1. subtract two numbers DBL such that the result is not incorporated. (Say, 3.2 - 3.1)

  2. compare the result with a constant/control that is on the result of the subtraction (in the example, 0.1)

  3 see the output of the comparison.

  If the result of the subtraction is an integer, the Boolean result is (as expected). If the result is not complete, the comparison fails.

  (Now, if I simply compare two floating point numbers, it works, so the issue is not with the node comparison itself, but with the data that is entered to the node). Can someone understand why this happens? It's unexpected, it's a pretty serious bug.

  It is provided with all programming languages. Numbers do not have an exact binary floating-point representation. This has been discussed endlessly. Never use the equal function with floats. You can use the function in the range and force.

• Computer started to delay the result with a click of a button, etc. by seveal seconds.

  Have aw computer laptop Dell Inspiron 1501 XP SP3. Computer started to delay the result with a click of a button, etc. by seveal seconds.  A ran the anti-virus, malware search, keylogers search and found nothing.  The delay also occurs when you use an application such as CorelDRAW, Word, WordPerfect programs, etc.  any ideas what is happening or where to look? Thank you.

  You experience this delay all the time, or they occur from time to time?

  Could complete you the following procedure to obtain information about your current system and post here, so I can be more specific in suggestions.
  0 close the programs as open as you can before the first step.
  1 copy the following line below exactly as it appears:
  Taskpad cmd /C /V > tempo & tempo notebook
  2. press on + R
  3. paste copied line run window and press enter or click Ok.
  4 copy all the information from the Notepad window. (The list can be long, you can use + a combination to select all)
  5 paste info copied to the next reply.
  6. after that you can close the Notepad window.

• Help in parsing the XML result with ksoap2

  Hi, I have another problem. I used KSOAP2 to call a web service net but when I catch him to display the result with a selectionneret, it shows the following screen:

  

  reading on the web, I didn't find a good way to analyze the result. Could you help me with this? Thanks in advance

  Thanks, the problem here is that we use the same webservice for more devices and a web page in .NET) that's why we use this webservice. Anyway thanks for the help. I read a lot of posts and the only way is perhaps to save the XML document in the SD card

• Showing results with one decimal two. Force the decimal.

  Hello

  Im a simple computing of writing device.

  You enter a digit, press one of the two buttons to multiply by a number, and then the result is displayed. The result is copied hide the result from the button you press on and visa versa.

  I'm having a problem to display the result with a decimal point two constant.

  I'm using strings and so do not know how to do this.

  Here is my code:

  import flash.events.MouseEvent;

  restrict entry to only numbers textfield

  txtInput.Restrict = "0-9";

  restrict the input textfield only a two-digit

  txtinput.maxChars = 6;

  event listeners

  btnW.addEventListener (MouseEvent.CLICK, WHandler);

  btnC.addEventListener (MouseEvent.CLICK, CHandler);

  btnW.addEventListener (MouseEvent.CLICK, hideC);

  btnC.addEventListener (MouseEvent.CLICK, hideW);

  functions

  function WHandler (e:MouseEvent): void

  {

  calculation of white

  var answerW:Number = Number (txtinput.text) * Number (0.90);

  txtWResult.text = answerW.toString ();

  }

  function of CHandler (e:MouseEvent): void

  {

  calculation of the color

  var answerC:Number = Number (txtinput.text) * Number (0.99).

  txtCResult.text = answerC.toString ();

  }

  function hideC (e:MouseEvent): void

  {

  Hide the result color

  txtCResult.visible = false;

  txtWResult.visible = true;

  }

  function hideW (e:MouseEvent): void

  {

  Hide the white result

  txtWResult.visible = false;

  txtCResult.visible = true;

  }

  After having had a look online I found these two resources:

  http://helpx.Adobe.com/Flash/KB/rounding-specific-decimal-places-Flash.html

  and

  http://StackOverflow.com/questions/11469321/decimals-to-one-decimal-place-in-AS3

  But I'm confused when combining these techniques with ropes.

  Any help would be greatly appreciated,

  Thanks in advance

  Mr B

  Use the toFixed() class number instead of the toString() method.  The result is a string that contains the number of decimal places you specify.

  var answerW:Number = Number (txtinput.text) * Number (0.90);

  txtWResult.text = answerW.toFixed (2);

  var answerC:Number = Number (txtinput.text) * Number (0.99).

  txtCResult.text = answerC.toFixed (2);