How to calibrate load cell from testing stand
Here you see the hybrid rocket motor i build for a school project. The motor is fixed on a linear rail and push on the load cell at the back. I was wondering how do I need to calibrate it ?
- I tried by setting 10N on the load cell directly and obtained a scale value of 108 (in blue)
- but when I tried calibrating it by pulling 10N on the rocket nozzle by pulling a string around the mother and with a dynamometer I get 25 of scale value. (In red)
So with the first method I get around 10N of trust but with the second like 60. So which one is accurate ? I mean I understand that using the second method allow to delete the friction of the linear rail (that is also by the way not very smooth) but this amount of gap between the scale values is so huge. Thanks in advance.
By the way the motor perform well with ASA/ABS and GOX.
Here you see the hybrid rocket motor i build for a school project. The motor is fixed on a linear rail and push on the load cell at the back. I was wondering how do I need to calibrate it ?
- I tried by setting 10N on the load cell directly and obtained a scale value of 108 (in blue)
- but when I tried calibrating it by pulling 10N on the rocket nozzle by pulling a string around the mother and with a dynamometer I get 25 of scale value. (In red)
So with the first method I get around 10N of trust but with the second like 60. So which one is accurate ? I mean I understand that using the second method allow to delete the friction of the linear rail (that is also by the way not very smooth) but this amount of gap between the scale values is so huge. Thanks in advance.
By the way the motor perform well with ASA/ABS and GOX.