Mathematics

Someone asked me whether I do the mathematics before I do an electronic design. In fact I work almost wholly on intuitive knowledge of the parts, then do the mathematics afterwards, or in refining the design. Nor am I very good at mathematics. I battled with the inverse cube law for my latest design. But here are some calculations that the publisher did:

• It's official. My magnetometer's sensitivity is 30 microgauss
• Its gain (amplification) is 25 million in each of two channels

OBSERVATION: These are extreme figures. However, things may look different when a design is brought into contact with the real world, where ideal performance may be compromised by many things. In the case of this design, turbulence in the ocean, mineralisation of the earth, even activity on the surface of the sun.