Science Forums 2

[ozi-rock]

Hi guy's I'm currently studying for the repeat of the measurement and signals exam, I just can't figure this subject out but anyway I have a question if anyone can shed some light on, it's probably stupidly simple but here it is:

A liquid level sensor has an output range of 0 to 15cm. Use the calibration results given in the table to estimate the maximum hysteresis as a percentage of f.s.d.

Level h (cm) 0 1.5 3 4.5 6 7.5 9 10.5 12 13.5 15
Voltage output increase h 0 0.35 1.42 2.4 3.43 4.35 5.61 6.5 7.77 8.85 10.2
Voltage output decrease h 0.14 1.25 2.32 3.55 4.43 5.7 6.78 7.8 8.87 9.65 10.2

The answer given is 13.2%

I know %f.s.d = n max divided by Y max - Y min all multiplied by 100. so I got the largest difference between the input and output which I think is n max and I took Y min to be 0 and Y max to be 15. This left me with [2.19/(15-0)]*100 which = 14.6%.

Can anyone point out where I'm going wrong?