SC-2043-SG Signal Conditioning high gain need

[altelec]

I�m working in a continuous weighting machine, for grading application.
I�m using a PCI 6013 ( 16 bit A/D resolution) low cost boards, with a SC-2043-SG eight channel Signal Conditioning and a load cell with 2mv/v strain gauges. For mechanical reliability considerations, load cells works within a range of 10% of full load.
PCI 6013 has a max sensibility of +/- 100 mv. And SC-2043-SG has a fixed gain of only 10, on each channel.
Internal excitation voltage for the strain gauge bridge is 2.5V. ( I�m thinking to use an external excitation source of 10 VCC, to increase strain gauge output).
Under this working condition, I need at least an additional gain of 10 to 50 to obtain 15 bit resolution.
Some suggestions?

Regards,


Alberto Tubía
tubial@lq.com.ar


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ALTELEC Ing. Electr.
Lamadrid 328
7500 Tres Arroyos
Buenos Aires
ARGENTINA
54 2983 422579
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[RIO-Todd]

Hello Alberto,

How did you calculate the +/- 100 mV sensibility for the PCI-6013? With the 16-bits of resolution you will be able to achieve much better resolution with the PCI-6013. Additionally, the PCI-6013 has gains of .5, 1, 10, and 100 to further increase the resolution of your readings. Using the +/- 0.05 V input range (gain of 100), the resolution is on the order of 4 uV. You can change the input range within your software program to +/- 0.05 V and then NI-DAQ will automatically set the gain of the device to 100 to achieve the maximum resolution. That will give you plenty of resolution for your strain gauge readings.

I've linked the 6013 manual below that has all of the specifications for the device (gains, resolution, etc..) for you to take a look at.


NI 6013/6014 Family Specifications
http://digital.ni.com/manuals.nsf/webAdvsearch/6053BACD268F7E6D86256DA200722B67?OpenDocument&vid=niwc&node=132100_US

I hope this helps.

Regards,

Todd D.
NI Applications Engineer