Solenoid Question

jmcmillian

1. The problem statement, all variables and given/known data
I ran an experiment to find the magnetic field inside a solenoid at different points using a magnetic sensor, attached to a computer and interface. Starting at the center of the solenoid and moving outwards to the end, I collected points at 1cm increments (starting at the center = 0cm, and then moving outwards to 6cm for each half of the solenoid).

I calculated what the field should be theoretically at each point, and compared it to my findings from the experiment by using basic (%) error analysis.

My experimental values were as much as 16% lower than the theoretical values and as little as 2/3%.

What I noticed was that the error % was the greatest when the sensor was at the center of the solenoid and declined as the sensor was moved towards the end of the solenoid. What I don't understand is if the magnetic field is strongest in the center of the solenoid, why is the error the highest? I would think that a sensor would have an easier time accurately picking up a strong magnetic field as opposed to a weaker field.

2. Relevant equations
http://www.mountainescapesproperties.com/Magfig4.gif


3. The attempt at a solution
Distance Experiment B Theo. B Error
(cm) (mT) (mT) (%)
0.000 5.056 6.045 16.36062862
1.000 5.007 5.964 16.04627767
2.000 5.039 5.721 11.92099283
3.000 5.023 5.531 9.184595914
4.000 5.068 4.820 5.145228216
5.000 4.527 4.229 7.046583117
6.000 3.608 3.612 0.09691264
-1.000 5.031 5.964 15.64386318
-2.000 5.023 5.721 12.20066422
-3.000 5.019 5.531 9.256915567
-4.000 5.039 4.820 4.543568465
-5.000 4.600 4.229 8.772759518
-6.000 3.588 3.612 0.650699155