INTERACTIVE EXPERIMENTS AND EXHIBITS
MEASUREMENT OF MAGNETIC FIELDS
The method we have chosen is based on the recent availability of low-cost Hall Effect probes with the proper characteristics. Below we see the circuit of the instrument designed so as to facilitate its construction.
Here are the probes of the instrument:
The value of the magnetic field at that point is shown on the tester. Among other things, the instrument is sensitive enough to give a precise indication of the north-south direction of the earthís magnetic field, which is approximately 0.40 Gauss at our latitude.
Here we have everything ready for verification of the theory:
And here is this instrument in the measurement of the field around a straight electrified wire to verify Biot and Savartís Law.
The diagram of the apparatus:
The nominal sensitivity given for the Hall probe used is 3.125 mV/Gauss, with a measurable maximum of about 800 Gauss = 0.08 Tesla. This circuit has ranges of 1, 10, 100, 1000 Gauss at the bottom scale of 1V of the tester, thus with a tester that indicates 10 mV, we have appreciable variations in the continuous fields of 10 mGauss.