Smallest force/weight that can be measured ?

[Jjazari]

Hello everyone, so i am newbie at this whole signal measuring thing.  I want to ask several question. Assume i want to measure force / weight using honeywell model 31 load cell that has some spec :

• Sensitivity : 20 mv/v
• Load range : 500 g
• Excitation: 5 Vdc

And connect it with NI-9237, so

My question is :

• What is resolution or smallest weight/force that can be measured by this system ?
• It is said in spec that NI-9237 has built-in amplifier and +-25 mv/v input range, is that means that my load cell output will be amplified from +-20 mv/v to +-25 mv/v ?

Thanks.

[Henrik_Volkers]

Hook it up and do measurements.

Your limitations will be drift, hystereses, noise , ... acceleration, air turbulences,,,  🙂

[Jjazari]

Yeah thanks for your response, unfortunately i don't have the product yet (load cell, Ni-9949, Ni-9237) because i want to make sure first before buy those product.

I see that in the load cell datasheet, its resolution is infinite (because analog signal i guess(?)), so i assume to look the digital resolution of the NI-9237. From my understanding

• If my understanding of ni-9237 will amplify output from +-20 mv/v to +-25 mv/v correct, does it mean the ideal resolution is just calculate (1000 gram / 2^24) ?
• Or the +-25 mv/v input range is actually just mean the range load cell output that ni 9237 accept (so output of +- 20 mv/v is acceptable to feed to ADC)

Is this correct ?

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@Henrik_Volkers wrote:

Hook it up and do measurements.

Your limitations will be drift, hystereses, noise , ... acceleration, air turbulences,,,  🙂

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