Specification question for NI-9219 For Full Bridge Torque Measurment

[MrQuestion-CW]

I have a cDAQ with a NI-9219 and I'm planning on using it with a TQ513-2k.  I have questions if the Full bridge configuration of the NI9219 will work with my applicaitons.

I'm looking at the specifications of the NI-9219 can only go down to 7.8 mV/V

And the Load resistance looks like is only configurable for 350 ohm or 120 ohm at 2.7V and 2.2V excitation.

Attached clip from the TQ513-25 torque sensor.

It has been a few years since I have worked with bridge circuits.

The Excitation voltage I don't think is nearly as important.

But when I look at the input ranges for the NI9219 I see +/7.8mV/V

Table 5 and Table 6 makes this card look like it can't go below 7.8mV/V accuracy

Also, I see that in the NI-9219 datasheet the nominal load resistance is 350 ohm and 120 ohm. Will this even work with 1,000 ohm nominal resistance?

I was given this card and sensor to work with, but when I look at the details I don't' think this is combination of card and load cell can work together.

Can I please get a second opinion? 

Regards,

[GerdW]

Hi Mr,

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@MrQuestion-CW wrote:

I was given this card and sensor to work with, but when I look at the details I don't' think this is combination of card and load cell can work together.

Can I please get a second opinion? 

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Well, NI doesn't specify a 1000Ohm bridge - but that doesn't mean you cannot use it…

I see two options:

1. Just connect the bridge as recommended and see what you get. The excitation voltage should be a little higher than for 350Ohm, but still (much) less than the allowed 20V…
   (The 7.8mV/V is just a measurement range, the module can also measure 2.0mV/V.)
2. Use your own excitation voltage source and use the NI9219 in "voltage measurement" mode. Do the calculations (to get mV/V) on your own…