Deriving responsivity in Hz/nT

If response of the sensor is: P=a.B+c

where P is the period of the sensor pulse output stream, in magnetic field B, and a and c are constants. Then, differentiating P wrt B, dP/dB=a

But F=1/P, where F is the frequency of the pulse stream. So, dF/dP = -1/P2

We want dF/dB, which is equal to (dF/dP).(dP/dB)   i.e. -a/P2 or -a.F2 . So, the if the response to magnetic field is linear in pulse period P, then the responsivity in Hz/nT will increase as the square of the pulse frequency F.

From the table, the slope (dB/dP) is about 30 Gauss/millisecond. This is 30.105 gamma/millisecond, or 30.105.103   =30.108 nT/second. So, the constant a = 1/30.108 seconds/nT.

From the above, dF/dB = -a.F2 . Assuming F = 60 kHz then dF/dB becomes (6.104)2/(30.108) = 36/30 = 1.2 Hz/nT.