Strain Gauge Measurements

[gdk0021]

Hey Everyone, 

 I'm a first time NI and Labview user, I'm currently setup with a NIcDAQ - 9189 and NI 9236 module, to which I have a Omega KFH series three leads, 120 ohms strain gauge connected to CH0. I have been using instructions from an NI vidoe tutorial to setup strain measurements, however on following the instructions adn trying to calibrate i'm getting hit with error 201398. I have tried changing values to what is suggested on the error message, but the same error message pops up with different values. I have attached images of my configuration and error message.

I will be grateful if someone can advise me on how to overcome this issue.

If i'm missing information that you need to help troubleshoot this please let me know.

Thanks

[RavensFan]

You say you have an NI-9236 module which is for 350 ohm 1/4 bridge strain gages.

But you also say you are using a 120 ohm strain gage.

Are you sure you have the correct equipment?  Those numbers don't match.

[gdk0021]

Hey Ravensfan, 

Thank you for responding, Is the NI-9236 module only be used for 350 ohm 1/4 bridge strain gauges?

From what I have understood this can be changed on the configuration page setup. 

On the configuration page I have input the corresponding gauge factor and gauge resistance (as shown in the attached file), shouldn't this allow me to work with a 120 ohm strain gauge  ?

Thanks

[RavensFan]

Yes.  That's what the specs say.  the NI-9236 is only for 350 ohm 1/4 bridges.  There is another module the 9235 for a 120 ohm gage.  The value you key into the task is probably used in the calculation of strain, but the key thing with is 1/4 bridge strain gage is that you need a bridge completion resistor that matches your strain gage.  That is why there are two different model numbers for the module.  One has a 120 ohm completion resistor.  The other has a 350 ohm.  That is why won't allow you to work with the wrong gage.

With the wrong module, the bridge is too unbalanced and can't be measured, thus giving you the kind of error you are seeing.

[gdk0021]

Thank you for clarifying that, I will order some 350 ohm gauges and try again. I appreciate your help.