Dear,
I have a problem while amplifying the signal of a load cell by using a INA125P (integrato)
I am not able to achieve a defined value under a certain limit. Here following some examples:
If a insert the Arduino ADV value read without load =0, the error is spread on all measurements. If I detract it I still experience no detection untill a certain limit.
By using a 200N load cell I get a value (related to the gain set), of about 20 ADC without load, which finally correspond to a initial reading threshold of about 0,7 - 0,8 N.
Normally we use 3000 N load cell. The threshold moves consequently thus preventing low loads detection that yet become significant ( about 10%).
I also cannot perform load cell calibration, as normally it is applied by linking the ADC value to 0 load and the FS to the relevant value. This because 0 value is underneath the threshold.
By resuming, it is like the load cell zero was under the threshold amplifier reading.
So, If I could move the zero value to a slightly higher tension, I should have solved the problem. But I do not know how to get this done.
To simplify:
If I have not load reading under the reading threshold I will never be able to calibrate these.
Let's consider the example of a Kitchen balance that starts to weigh right over the 100 gr. value ( it would not visualize 99 gr, yet it would visualize 101 gr). If I place a 80 gr plate ( but of course I do not know it before...) and then I want to weigh 500 sugar gr, how can I detract the plate weight?
Enclosed Scheme picture
Thanks,
Sergio
