NI 9237 with NI 9945 using DAQ Assistant for Strain Gauge Showing Output with Vex value

[wanized11]

Hi Everyone,

I am new to Labview. As per the subject, I am using NI 9237 with NI 9945 using DAQ Assistant for strain gauge showing output with Vex value. I am setting up a quarter bridge strain gauge. I already put in DAQ Assistant. As for the setup, I put in 3.3 as Vex value, for example. The output value is just +-0.0033. Even when I tried bending the strain gauge, the value does not show any changes. I am definitely out of ideas on what should I do next.

Please assist me. Thank you in advance.

[santo_13]

I would double-check the wiring connections and also check the resistance with a multimeter to ensure that there is no break in the strain gage.

[wanized11]

Hi Santhosh,

Thank you for your reply. This has been quite sometimes but I haven't solve it yet. 

I now try with NI 9944. I have checked the circuit connection in NI 9944 and everything seems right (I referred to the NI guide). I have measured the voltage across the strain gauge and it's 1.6V. I double checked the strain gauge resistance and see if there is anything's wrong with it, but the strain gauge's still showing 120 ohm. Thus, i doubt that from NI 9944 to strain gauge connection has error here.

But i was wondering if there is anything's wrong with RJ-50 cable, will it cause output error like what I'm seeing now? I was actually able to get strain value about 3 months ago so this is really strange for me. 

Thanks in advance.

[wanized11]

Hi Santhosh,

Thank you for your reply. This has been quite sometimes but I haven't solve it yet. 

I now try with NI 9944. I have checked the circuit connection in NI 9944 and everything seems right (I referred to the NI guide). I have measured the voltage across the strain gauge and it's 1.6V. I double checked the strain gauge resistance and see if there is anything's wrong with it, but the strain gauge's still showing 120 ohm. Thus, i doubt that from NI 9944 to strain gauge connection has error here.

But i was wondering if there is anything's wrong with RJ-50 cable, will it cause output error like what I'm seeing now? I was actually able to get strain value about 3 months ago so this is really strange for me.

Thanks in advance.

[santo_13]

It is possible that the RJ-50 cable might be damaged, you could test out the RJ-50 cable using the Continuity test mode of a DMM.