# Calibration Without Weight

Question asked by dclm on Feb 13, 2014
Latest reply on Mar 3, 2014 by JohnnyG

Hi,

There are a lot of scale manufacturers that claims to have calibration without actually putting weight on to the scale. How are they doing such a thing?

For me calibration is;

1-) Suppose you have a loadcell with a dead weight. Dead weight is unknown. Can change in time because of environmental factors.

2-) When weighing hopper is empty suppose 16 bit A/D conversion results in decimal 10000.

3-) You put a weight of 500gr. Now A/D conversion result is 60000.

4-) For 500gr weight decimal 50000 change. store that value.

5-) Put a unknown weight.

6-) If A/D is 40000. 40000-10000 = net 30000 change is A/D

7-) If 50000 changes for 500gr what weight changes A/D 30000. Solve equation and calculation result is 300gr.

For me this is how to calculate weight of a unknown product.

Suppose there is a problem on weighing result. Or when you put weight 500gr on scale it shows 500.5gr. How can you correct it without a reference?

As far as I remember AD7730 has internal full scale, internal zero scale, system zero scale, system full scale calibration methods. Where does these calibration methods stands with MY calibration method.

Is it possible to make a calibration without weight with AD7730 for example?

Regards,

DC