Using a S2M transducer to read force measurements. New to LabVIEW.

[Vin91]

I was pushing on the sensor with my hands on and off. Not continuously. I assumed that this would lead to some peaks but there were none observable.

[cbutcher]

If you set the "Offset Null" to true before starting the VI (and then start it with no load applied) does anything change?

I'm only guessing now, but I wonder if there's some issue with the min/max values and conversion (since I'd expect +-5mV to be your full scale voltage, given 2mV/V and 2.5V excitation), but I think the 0.008 is actually N, not mV, right?

If you read directly an analog input (as voltage, not force) do you get variation? I'm not sure you'll be able to use all of the convenience features if you do this - you might need to separately wire a power supply, and your accuracy might be horrible, but as a (has response/no response) kind of test you might(?) see something (and that could rule out a broken sensor).

[Vin91]

Hey,

Yeah I tried this voltage program as well. I have attached the VI here. Similar procedure. I started the program and then squeezed the sensor with my hands to see if there is a response. Let me know if I should try something differently.

[GerdW]

Hi Vin,

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@Vin91 wrote:

Yeah I tried this voltage program as well. I have attached the VI here. Similar procedure. I started the program and then squeezed the sensor with my hands to see if there is a response. Let me know if I should try something differently.

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First recommendation: don't attach BMP files, use PNG instead! (Much smaller files!)

Other recommendation:

1. Use a simple power supply of ~5V.
2. Connect the power supply to the excitation inputs of your sensor.
3. Use a simple DMM and connect it to the signal output of your bridge-type sensor.
4. Measure the output voltage with/without pushing the force sensor…
5. That should give you a noisy signal around zero (when not pushing the sensor) and some other value (with added noise) when pushing the sensor.

A very simple check to test the sensor working correctly…

[Vin91]

Hey,

Haha thanks will remember that for the next time. Ok I will try that. I have access to a DMM but maybe not to the 5V source.

[GerdW]

Hi Vin,

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@Vin91 wrote:

Ok I will try that. I have access to a DMM but maybe not to the 5V source.

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No simple USB charger outputting 5V?

No cheap batteries? Just two AAA cells already provide 3V…

[Vin91]

Hey,

Sorry for the late reply. I managed to connect my sensor to a P3 strain indicator and in full bridge mode I did receive a signal back when I pressed on it. To do this, I had to do a weird thing which was connect the blue and green wires together in one slot and the black and gray wires together in another slot. However after doing this I received a response from the machine which I understood as that the sensor is working. However when I use these same connections in my NI 9219 receiver, I am not receiving any signal at all which is different from the previous small signals that I was receiving. I am a little confused with this result.

[GerdW]

Hi Vin,

gray/black and blue/green are connected anyway, so that should not make a difference (from the point of view of the sensor). (See page 2 in your datasheet!)

Can you measure the resistance between gray/black and blue/green (each combination) and between white and red using a simple DMM?

[Vin91]

Hey, sorry yeah I misunderstood it and that was my fault. I have checked again on LabVIEW to see if my wiring has some problem but I am again getting some weird results. Attaching it here.  I will also check the voltage with the DMM in some time as I don't have access to that yet.

Regards,

Vin

[Vin91]

Hey thank you all for the help. I connected my strain gauge to the P3 strain indicator and I got no appreciable result. The variance was very high and it was not giving me repeatable readings. So I concluded that the gauge is broken and decided to order a new one. Thanks again for all the help.