Accuracy of an FTA-scale

Hello Peter1,

The calculation of the accuracy is:

accuracy = Emax x √N / Y

In your case it is:

- Emax = 100 kg

- N = 3 (= number of load cells)

- Y = 1 / vmin x 100 (with vmin = 0.009 from the technical data sheet) = 1 / 0.009 x 100 = 11111

accuracy = Emax x √N / Y = 100 kg x √3 / 11111 = 16 gr

Best regards

Siwarexi

Hello monkeyjacob,

The formula to calculate Y is:

Y = 1 / (v_min) = 1/(0.009%) = 1/(0.009/100) = 1 / 0.009 x 100 = 11111

“x 100” is coming from the %.

It’s not E_max.

Best regards

Siwarexi

Hello monkeyjacob,

Well, unfortunately I don’t know about some documentation about the accuracy.

But in general, the calculation of the accuracy is:

1. Calculation of the laod cells:

E_maxx √(N) / Y

2. Calculation of the electronic module:

deltaU_minx E_maxx N / C / U_exc

E_max= nominal load of one load cell

N = number of load cells

Y = highest scale interval from the technical data sheet of the load cell

deltaU_min= 0.5 uVfor the WP321

C = characteristic value from the technical data sheet of the load cell (e.g. 2mV/V)

U_exc= power supply for the load cells from the electronic module (e.g.: WP321 = 4.85)

Now, you have to use the higher value from the two calculations.

That’s the accuracy of your whole scale.

Best regards

Siwarexi