load cells

If a load cell has a bridge of strain gages with sensibility of 2 mV/V, and I apply a V=5v, and the range of force is from 0 to100 Kg, is correct to say that with the max force applied the V difference should be 100 * 5

--- No. What the 2mV/V means is that for every volt of excitation, the bridge will output 2 millivolts with the maximum rated mechanical load on the load cell. Like this:

k Vin Fin Vout = ----------- Fmax

where k is the rated sensitivity of the load cell in mV/V Vin is the excitation voltage Fin is the force exerted on the load cell Fmax is the load scale's full-scale force rating

In your case we'll have: 2mV ----- * 5V * 100kgF 1V Vout = ----------------------- 100kgF

which, after the V's and the 100kgF's cancel out leaves you with:

Vout = 2mV * 5 = 10mV

-- John Fields Professional Circuit Designer

Nononononono unless it's given as 2mV/V/kg (which it isn't)

The output at maximum load will be 2mV * 5 = 10mV.

Paul Burke

Force is correctly measured in Newtons ! To use the old fashioned way of talking ... 1 N = 1 kgf ( not 1 kg ) = 1kg*9.81m/s. F = ma. Check the sensitivity spec.

Other than that, your calculation seems ok

Graham